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  • Appropriate design / technologies to handle dynamic string formatting?

    - by Mark W
    recently I was tasked with implementing a way of adding support for versioning of hardware packet specifications to one of our libraries. First a bit of information about the project. We have a hardware library which has classes for each of the various commands we support sending to our hardware. These hardware modules are essentially just lights with a few buttons, and a 2 or 4 digit display. The packets typically follow the format {SOH}AADD{ETX}, where AA is our sentinel action code, and DD is the device ID. These packet specs are different from one command to the next obviously, and the different firmware versions we have support different specifications. For example, on version 1 an action code of 14 may have a spec of {SOH}AADDTEXT{ETX} which would be AA = 14 literal, DD = device ID, TEXT = literal text to display on the device. Then we come out with a revision with adds an extended byte(s) onto the end of the packet like this {SOH}AADDTEXTE{ETX}. Assume the TEXT field is fixed width for this example. We have now added a new field onto the end which could be used to say specify the color or flash rate of the text/buttons. Currently this java library only supports one version of the commands, the latest. In our hardware library we would have a class for this command, say a DisplayTextArgs.java. That class would have fields for the device ID, the text, and the extended byte. The command class would expose a method which generates the string ("{SOH}AADDTEXTE{ETX}") using the value from the class. In practice we would create the Args class as needed, populate the fields, call the method to get our packet string, then ship that down across the CAN. Some of our other commands specification can vary for the same command, on the same version, depending on some runtime state. For example, another command for version 1 may be {SOH}AA{ETX}, where this action code clears all of the modules behind a specific controller device of their text. We may overload this packet to have option fields with multiple meanings like {SOH}AAOC{ETX} where OC is literal text, which tells the controller to only clear text on a specific module type, and to leave the others alone, or the spec could also have an option format of {SOH}AADD{ETX} to clear the text off a a specific device. Currently, in the method which generates the packet string, we would evaluate fields on the args class to determine which spec we will be using when formatting the packet. For this example, it would be along the lines of: if m_DeviceID != null then use {SOH}AADD{ETX} else if m_ClearOCs == true then use {SOH}AAOC{EXT} else use {SOH}AA{ETX} I had considered using XML, or a database to store String.format format strings, which were linked to firmware version numbers in some table. We would load them up at startup, and pass in the version number of the hardwares firmware we are currently using (I can query the devices for their firmware version, but the version is not included in all packets as part of the spec). This breaks down pretty quickly because of the dynamic nature of how we select which version of the command to use. I then considered using a rule engine to possibly build out expressions which could be interpreted at runtume, to evaluate the args class's state, and from that select the appropriate format string to use, but my brief look at rule engines for java scared me away with its complexity. While it seems like it might be a viable solution, it seems overly complex. So this is why I am here. I wouldn't say design is my strongest skill, and im having trouble figuring out the best way to approach this problem. I probably wont be able to radically change the args classes, but if the trade off was good enough, I may be able to convince my boss that the change is appropriate. What I would like from the community is some feedback on some best practices / design methodologies / API or other resources which I could use to accomplish: Logic to determine which set of commands to use for a given firmware version Of those command, which version of each command to use (based on the args classes state) Keep the rules logic decoupled from the application so as to avoid needing releases for every firmware version Be simple enough so I don't need weeks of study and trial and error to implement effectively.

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  • Non use of persisted data – Part deux

    - by Dave Ballantyne
    In my last blog I showed how persisted data may not be used if you have used the base data on an include on an index. That wasn't the only problem ive had that showed the same symptom.  Using the same code as before,  I was executing similar to the below : select BillToAddressID,SOD.SalesOrderDetailID,SOH.CleanedGuid from sales.salesorderheader SOH join Sales.SalesOrderDetail SOD on SOH.SalesOrderID = SOD.SalesOrderID But,  due to a distribution error in statistics i found it necessary to use a table hint.  In this case, I wanted to force a loop join select BillToAddressID,SOD.SalesOrderDetailID,SOH.CleanedGuid from sales.salesorderheader SOH inner loop join Sales.SalesOrderDetail SOD on SOH.SalesOrderID = SOD.SalesOrderID   But, being the diligent  TSQL developer that I am ,looking at the execution plan I noticed that the ‘compute scalar’ operator was again calling the function.  Again,  profiler is a more graphic way to view this…..   All very odd,  just because ive forced a join , that has NOTHING, to do with my persisted data then something is causing the data to be re-evaluated. Not sure if there is any easy fix you can do to the TSQL here, but again its a lesson learned (or rather reinforced) examine the execution plan of every query you write to ensure that it is operating as you thought it would.

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  • A quick look at: sys.dm_os_buffer_descriptors

    - by Jonathan Allen
    SQL Server places data into cache as it reads it from disk so as to speed up future queries. This dmv lets you see how much data is cached at any given time and knowing how this changes over time can help you ensure your servers run smoothly and are adequately resourced to run your systems. This dmv gives the number of cached pages in the buffer pool along with the database id that they relate to: USE [tempdb] GO SELECT COUNT(*) AS cached_pages_count , CASE database_id WHEN 32767 THEN 'ResourceDb' ELSE DB_NAME(database_id) END AS Database_name FROM sys.dm_os_buffer_descriptors GROUP BY DB_NAME(database_id) , database_id ORDER BY cached_pages_count DESC; This gives you results which are quite useful, but if you add a new column with the code: …to convert the pages value to show a MB value then they become more relevant and meaningful. To see how your server reacts to queries, start up SSMS and connect to a test server and database – mine is called AdventureWorks2008. Make sure you start from a know position by running: -- Only run this on a test server otherwise your production server's-- performance may drop off a cliff and your phone will start ringing. DBCC DROPCLEANBUFFERS GO Now we can run a query that would normally turn a DBA’s hair white: USE [AdventureWorks2008] go SELECT * FROM [Sales].[SalesOrderDetail] AS sod INNER JOIN [Sales].[SalesOrderHeader] AS soh ON [sod].[SalesOrderID] = [soh].[SalesOrderID] …and then check our cache situation: A nice low figure – not! Almost 2000 pages of data in cache equating to approximately 15MB. Luckily these tables are quite narrow; if this had been on a table with more columns then this could be even more dramatic. So, let’s make our query more efficient. After resetting the cache with the DROPCLEANBUFFERS and FREEPROCCACHE code above, we’ll only select the columns we want and implement a WHERE predicate to limit the rows to a specific customer. SELECT [sod].[OrderQty] , [sod].[ProductID] , [soh].[OrderDate] , [soh].[CustomerID] FROM [Sales].[SalesOrderDetail] AS sod INNER JOIN [Sales].[SalesOrderHeader] AS soh ON [sod].[SalesOrderID] = [soh].[SalesOrderID] WHERE [soh].[CustomerID] = 29722 …and check our effect cache: Now that is more sympathetic to our server and the other systems sharing its resources. I can hear you asking: “What has this got to do with logging, Jonathan?” Well, a smart DBA will keep an eye on this metric on their servers so they know how their hardware is coping and be ready to investigate anomalies so that no ‘disruptive’ code starts to unsettle things. Capturing this information over a period of time can lead you to build a picture of how a database relies on the cache and how it interacts with other databases. This might allow you to decide on appropriate schedules for over night jobs or otherwise balance the work of your server. You could schedule this job to run with a SQL Agent job and store the data in your DBA’s database by creating a table with: IF OBJECT_ID('CachedPages') IS NOT NULL DROP TABLE CachedPages CREATE TABLE CachedPages ( cached_pages_count INT , MB INT , Database_Name VARCHAR(256) , CollectedOn DATETIME DEFAULT GETDATE() ) …and then filling it with: INSERT INTO [dbo].[CachedPages] ( [cached_pages_count] , [MB] , [Database_Name] ) SELECT COUNT(*) AS cached_pages_count , ( COUNT(*) * 8.0 ) / 1024 AS MB , CASE database_id WHEN 32767 THEN 'ResourceDb' ELSE DB_NAME(database_id) END AS Database_name FROM sys.dm_os_buffer_descriptors GROUP BY database_id After this has been left logging your system metrics for a while you can easily see how your databases use the cache over time and may see some spikes that warrant your attention. This sort of logging can be applied to all sorts of server statistics so that you can gather information that will give you baseline data on how your servers are performing. This means that when you get a problem you can see what statistics are out of their normal range and target you efforts to resolve the issue more rapidly.

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  • Sub query pass through

    - by SQL and the like
    Occasionally in forums and on client sites I see conditional subqueries in statements. This is where the developer has decided that it is only necessary to process some data under a certain condition.  By way of example, something like this : Create Procedure GetOrder @SalesOrderId integer, @CountDetails tinyint as Select SOH.salesorderid , case when @CountDetails = 1 then (Select count(*) from Sales.SalesOrderDetail SOD where SOH.SalesOrderID = SOD.SalesOrderID) end from sales.SalesOrderHeader...(read more)

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  • How to use a list of values in Excel as filter in a query

    - by Luca Zavarella
    It often happens that a customer provides us with a list of items for which to extract certain information. Imagine, for example, that our clients wish to have the header information of the sales orders only for certain orders. Most likely he will give us a list of items in a column in Excel, or, less probably, a simple text file with the identification code:     As long as the given values ??are at best a dozen, it costs us nothing to copy and paste those values ??in our SSMS and place them in a WHERE clause, using the IN operator, making sure to include the quotes in the case of alphanumeric elements (the database sample is AdventureWorks2008R2): SELECT * FROM Sales.SalesOrderHeader AS SOH WHERE SOH.SalesOrderNumber IN ( 'SO43667' ,'SO43709' ,'SO43726' ,'SO43746' ,'SO43782' ,'SO43796') Clearly, the need to add commas and quotes becomes an hassle when dealing with hundreds of items (which of course has happened to us!). It’d be comfortable to do a simple copy and paste, leaving the items as they are pasted, and make sure the query works fine. We can have this commodity via a User Defined Function, that returns items in a table. Simply we’ll provide the function with an input string parameter containing the pasted items. I give you directly the T-SQL code, where comments are there to clarify what was written: CREATE FUNCTION [dbo].[SplitCRLFList] (@List VARCHAR(MAX)) RETURNS @ParsedList TABLE ( --< Set the item length as your needs Item VARCHAR(255) ) AS BEGIN DECLARE --< Set the item length as your needs @Item VARCHAR(255) ,@Pos BIGINT --< Trim TABs due to indentations SET @List = REPLACE(@List, CHAR(9), '') --< Trim leading and trailing spaces, then add a CR\LF at the end of the list SET @List = LTRIM(RTRIM(@List)) + CHAR(13) + CHAR(10) --< Set the position at the first CR/LF in the list SET @Pos = CHARINDEX(CHAR(13) + CHAR(10), @List, 1) --< If exist other chars other than CR/LFs in the list then... IF REPLACE(@List, CHAR(13) + CHAR(10), '') <> '' BEGIN --< Loop while CR/LFs are over (not found = CHARINDEX returns 0) WHILE @Pos > 0 BEGIN --< Get the heading list chars from the first char to the first CR/LF and trim spaces SET @Item = LTRIM(RTRIM(LEFT(@List, @Pos - 1))) --< If the so calulated item is not empty... IF @Item <> '' BEGIN --< ...insert it in the @ParsedList temporary table INSERT INTO @ParsedList (Item) VALUES (@Item) --(CAST(@Item AS int)) --< Use the appropriate conversion if needed END --< Remove the first item from the list... SET @List = RIGHT(@List, LEN(@List) - @Pos - 1) --< ...and set the position to the next CR/LF SET @Pos = CHARINDEX(CHAR(13) + CHAR(10), @List, 1) --< Repeat this block while the upon loop condition is verified END END RETURN END At this point, having created the UDF, our query is transformed trivially in: SELECT * FROM Sales.SalesOrderHeader AS SOH WHERE SOH.SalesOrderNumber IN ( SELECT Item FROM SplitCRLFList('SO43667 SO43709 SO43726 SO43746 SO43782 SO43796') AS SCL) Convenient, isn’t it? You can find the script DBA_SplitCRLFList.sql here. Bye!!

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  • Entity Framework v1 &hellip; Brief Synopsis and Tips &ndash; Part 2

    - by Rohit Gupta
    Using Entity Framework with ASMX Web sErvices and WCF Web Service: If you use ASMX WebService to expose Entity objects from Entity Framework... then the ASMX Webservice does not  include object graphs, one work around is to use Facade pattern or to use WCF Service. The other important aspect of using ASMX Web Services along with Entity Framework is that the ASMX Client is not aware of the existence of EF v1 since the client solely deals with C# objects (not EntityObjects or ObjectContext). Since the client is not aware of the ObjectContext hence the client cannot participate in change tracking since the client only receives the Current Values and not the Orginal values when the service sends the the Entity objects to the client. Thus there are 2 drawbacks to using EntityFramework with ASMX Web Service: 1. Object state is not maintained... so to overcome this limitation we need insert/update single entity at a time and retrieve the original values for the entity being updated on the server/service end before calling Save Changes. 2. ASMX does not maintain object graphs... i.e. Customer.Reservations or Customer.Reservations.Trip relationships are not maintained. Thus you need to send these relationships separately from service to client. WCF Web Service overcomes the object graph limitation of ASMX Web Service, but we need to insure that we are populating all the non-null scalar properties of all the objects in the object graph before calling Update. WCF Web service still cannot overcome the second limitation of tracking changes to entities at the client end. Also note that the "Customer" class in the Client is very different from the "Customer" class in the Entity Framework Model Entities. They are incompatible with each other hence we cannot cast one to the other. However the .NET Framework translates the client "Customer" Entity to the EFv1 Model "customer" Entity once the entity is serialzed back on the ASMX server end. If you need change tracking enabled on the client then we need to use WCF Data Services which is available with VS 2010. ====================================================================================================== In WCF when adding an object that has relationships, the framework assumes that every object in the object graph needs to be added to store. for e.g. in a Customer.Reservations.Trip object graph, when a Customer Entity is added to the store, the EFv1 assumes that it needs to a add a Reservations collection and also Trips for each Reservation. Thus if we need to use existing Trips for reservations then we need to insure that we null out the Trip object reference from Reservations and set the TripReference to the EntityKey of the desired Trip instead. ====================================================================================================== Understanding Relationships and Associations in EFv1 The Golden Rule of EF is that it does not load entities/relationships unless you ask it to explicitly do so. However there is 1 exception to this rule. This exception happens when you attach/detach entities from the ObjectContext. If you detach an Entity in a ObjectGraph from the ObjectContext, then the ObjectContext removes the ObjectStateEntry for this Entity and all the relationship Objects associated with this Entity. For e.g. in a Customer.Order.OrderDetails if the Customer Entity is detached from the ObjectContext then you cannot traverse to the Order and OrderDetails Entities (that still exist in the ObjectContext) from the Customer Entity(which does not exist in the Object Context) Conversely, if you JOIN a entity that is not in the ObjectContext with a Entity that is in the ObjContext then the First Entity will automatically be added to the ObjContext since relationships for the 2 Entities need to exist in the ObjContext. ========================================================= You cannot attach an EntityCollection to an entity through its navigation property for e.g. you cannot code myContact.Addresses = myAddressEntityCollection ========================================================== Cascade Deletes in EDM: The Designer does not support specifying cascase deletes for a Entity. To enable cascasde deletes on a Entity in EDM use the Association definition in CSDL for the Entity. for e.g. SalesOrderDetail (SOD) has a Foreign Key relationship with SalesOrderHeader (SalesOrderHeader 1 : SalesOrderDetail *) if you specify a cascade Delete on SalesOrderHeader Entity then calling deleteObject on SalesOrderHeader (SOH) Entity will send delete commands for SOH record and all the SOD records that reference the SOH record. ========================================================== As a good design practise, if you use Cascade Deletes insure that Cascade delete facet is used both in the EDM as well as in the database. Even though it is not absolutely mandatory to have Cascade deletes on both Database and EDM (since you can see that just the Cascade delete spec on the SOH Entity in EDM will insure that SOH record and all related SOD records will be deleted from the database ... even though you dont have cascade delete configured in the database in the SOD table) ============================================================== Maintaining relationships in Code When Setting a Navigation property of a Entity (for e.g. setting the Contact Navigation property of Address Entity) the following rules apply : If both objects are detached, no relationship object will be created. You are simply setting a property the CLR way. If both objects are attached, a relationship object will be created. If only one of the objects is attached, the other will become attached and a relationship object will be created. If that detached object is new, when it is attached to the context its EntityState will be Added. One important rule to remember regarding synchronizing the EntityReference.Value and EntityReference.EntityKey properties is that when attaching an Entity which has a EntityReference (e.g. Address Entity with ContactReference) the Value property will take precedence and if the Value and EntityKey are out of sync, the EntityKey will be updated to match the Value. ====================================================== If you call .Load() method on a detached Entity then the .Load() operation will throw an exception. There is one exception to this rule. If you load entities using MergeOption.NoTracking, you will be able to call .Load() on such entities since these Entities are accessible by the ObjectContext. So the bottomline is that we need Objectontext to be able to call .Load() method to do deffered loading on EntityReference or EntityCollection. Another rule to remember is that you cannot call .Load() on entities that have a EntityState.Added State since the ObjectContext uses the EntityKey of the Primary (Parent) Entity when loading the related (Child) Entity (and not the EntityKey of the child (even if the EntityKey of the child is present before calling .Load()) ====================================================== You can use ObjContext.Add() to add a entity to the ObjContext and set the EntityState of the new Entity to EntityState.Added. here no relationships are added/updated. You can also use EntityCollection.Add() method to add an entity to another entity's related EntityCollection for e.g. contact has a Addresses EntityCollection so to add a new address use contact.Addresses.Add(newAddress) to add a new address to the Addresses EntityCollection. Note that if the entity does not already exist in the ObjectContext then calling contact.Addresses.Add(myAddress) will cause a new Address Entity to be added to the ObjContext with EntityState.Added and it will also add a RelationshipEntry (a relationship object) with EntityState.Added which connects the Contact (contact) with the new address newAddress. Note that if the entity already exists in the Objectcontext (being part theOtherContact.Addresses Collection), then calling contact.Addresses.Add(existingAddress) will add 2 RelationshipEntry objects to the ObjectStateEntry Collection, one with EntityState.Deleted and the other with EntityState.Added. This implies that the existingAddress Entity is removed from the theOtherContact.Addresses Collection and Added to the contact.Addresses Collection..effectively reassigning the address entity from the theOtherContact to "contact". This is called moving an existing entity to a new object graph. ====================================================== You usually use ObjectContext.Attach() and EntityCollection.Attach() methods usually when you need to reconstruct the ObjectGraph after deserializing the objects as received from a ASMX Web Service Client. Attach is usually used to connect existing Entities in the ObjectContext. When EntityCollection.Attach() is called the EntityState of the RelationshipEntry (the relationship object) remains as EntityState.unchanged whereas when EntityCollection.Add() method is called the EntityState of the relationship object changes to EntityState.Added or EntityState.Deleted as the situation demands. ========================================================= LINQ To Entities Tips: Select Many does Inner Join by default.   for e.g. from c in Contact from a in c.Address select c ... this will do a Inner Join between the Contacts and Addresses Table and return only those Contacts that have a Address. ======================================================== Group Joins Do LEFT Join by default. e.g. from a in Address join c in Contact ON a.Contact.ContactID == c.ContactID Into g WHERE a.CountryRegion == "US" select g; This query will do a left join on the Contact table and return contacts that have a address in "US" region The following query : from c in Contact join a in Address.Where(a1 => a1.CountryRegion == "US") on c.ContactID  equals a.Contact.ContactID into addresses select new {c, addresses} will do a left join on the Address table and return All Contacts. In these Contacts only those will have its Address EntityCollection Populated which have a Address in the "US" region, the other contacts will have 0 Addresses in the Address collection (even if addresses for those contacts exist in the database but are in a different region) ======================================================== Linq to Entities does not support DefaultIfEmpty().... instead use .Include("Address") Query Builder method to do a Left JOIN or use Group Joins if you need more control like Filtering on the Address EntityCollection of Contact Entity =================================================================== Use CreateSourceQuery() on the EntityReference or EntityCollection if you need to add filters during deferred loading of Entities (Deferred loading in EFv1 happens when you call Load() method on the EntityReference or EntityCollection. for e.g. var cust=context.Contacts.OfType<Customer>().First(); var sq = cust.Reservations.CreateSourceQuery().Where(r => r.ReservationDate > new DateTime(2008,1,1)); cust.Reservations.Attach(sq); This populates only those reservations that are older than Jan 1 2008. This is the only way (in EFv1) to Attach a Range of Entities to a EntityCollection using the Attach() method ================================================================== If you need to get the Foreign Key value for a entity e.g. to get the ContactID value from a Address Entity use this :                                address.ContactReference.EntityKey.EntityKeyValues.Where(k=> k.Key == "ContactID")

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  • How do I create a "global variable" in Java such that all classes can access it?

    - by Chrystle Soh
    here's my problem: I have multiple classes that are part of the same package and they need access to a certain file path String filePath = "D:/Users/Mine/School/Java/CZ2002_Assignment/src/" Rather than declaring the same Filepath in every single class, is it possible to simply have a "global" type of variable of this FilePath so that all classes can access it and I only need to declare and update it once. Thanks

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  • MemoryFailPoint fires to early in WinXP 64

    - by msedi
    Hello, I have created a volume class (called VoxelVolume) with a self-organizing memory management, since the GC in C# didn't provide a good mechanism for managing contents of the volume for mapping, unmapping and remapping. Although I could have used the mechanisms of virtual memory, the problem is that the files are often too large to fit into the page file and I don't want to force the users to increase the pagefile size. Currently this system is working quite well and there is no problem in lacking resources and OutOfMemoryExceptions since the InsufficientMemoryException using the MemoryFailPoint works quite well. This was all testes on a 32bit WinXP system with 2GB of main memory. Running the same mechanism on 64bit system with 32GB of main memory also works well, but when the application runs the MemoryFailPoint suddenly throws an exception although 24GB of main memory are still free. Another point is when the MemoryFailPoint has fired once, it fires everytime and there is no chance to get rid of it. What I have read so far, that there is a small object and a large object heap (SOH and LOH). But only for the SOH the GC takes real care of and I can free the SOH from unused objects by applying GC.Collect() and GC.WaitForPendingFinalizers. The MemoryFailPoint is obviously the only way to get a little bit of control for the LOH, but since there is enough memory left on the system I see no reason why the MemoryFilePoint should fire. Is there any experience around here using the MemoryFailPoint? Thank you for your help Martin

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  • Joins in single-table queries

    - by Rob Farley
    Tables are only metadata. They don’t store data. I’ve written something about this before, but I want to take a viewpoint of this idea around the topic of joins, especially since it’s the topic for T-SQL Tuesday this month. Hosted this time by Sebastian Meine (@sqlity), who has a whole series on joins this month. Good for him – it’s a great topic. In that last post I discussed the fact that we write queries against tables, but that the engine turns it into a plan against indexes. My point wasn’t simply that a table is actually just a Clustered Index (or heap, which I consider just a special type of index), but that data access always happens against indexes – never tables – and we should be thinking about the indexes (specifically the non-clustered ones) when we write our queries. I described the scenario of looking up phone numbers, and how it never really occurs to us that there is a master list of phone numbers, because we think in terms of the useful non-clustered indexes that the phone companies provide us, but anyway – that’s not the point of this post. So a table is metadata. It stores information about the names of columns and their data types. Nullability, default values, constraints, triggers – these are all things that define the table, but the data isn’t stored in the table. The data that a table describes is stored in a heap or clustered index, but it goes further than this. All the useful data is going to live in non-clustered indexes. Remember this. It’s important. Stop thinking about tables, and start thinking about indexes. So let’s think about tables as indexes. This applies even in a world created by someone else, who doesn’t have the best indexes in mind for you. I’m sure you don’t need me to explain Covering Index bit – the fact that if you don’t have sufficient columns “included” in your index, your query plan will either have to do a Lookup, or else it’ll give up using your index and use one that does have everything it needs (even if that means scanning it). If you haven’t seen that before, drop me a line and I’ll run through it with you. Or go and read a post I did a long while ago about the maths involved in that decision. So – what I’m going to tell you is that a Lookup is a join. When I run SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 285; against the AdventureWorks2012 get the following plan: I’m sure you can see the join. Don’t look in the query, it’s not there. But you should be able to see the join in the plan. It’s an Inner Join, implemented by a Nested Loop. It’s pulling data in from the Index Seek, and joining that to the results of a Key Lookup. It clearly is – the QO wouldn’t call it that if it wasn’t really one. It behaves exactly like any other Nested Loop (Inner Join) operator, pulling rows from one side and putting a request in from the other. You wouldn’t have a problem accepting it as a join if the query were slightly different, such as SELECT sod.OrderQty FROM Sales.SalesOrderHeader AS soh JOIN Sales.SalesOrderDetail as sod on sod.SalesOrderID = soh.SalesOrderID WHERE soh.SalesPersonID = 285; Amazingly similar, of course. This one is an explicit join, the first example was just as much a join, even thought you didn’t actually ask for one. You need to consider this when you’re thinking about your queries. But it gets more interesting. Consider this query: SELECT SalesOrderID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276 AND CustomerID = 29522; It doesn’t look like there’s a join here either, but look at the plan. That’s not some Lookup in action – that’s a proper Merge Join. The Query Optimizer has worked out that it can get the data it needs by looking in two separate indexes and then doing a Merge Join on the data that it gets. Both indexes used are ordered by the column that’s indexed (one on SalesPersonID, one on CustomerID), and then by the CIX key SalesOrderID. Just like when you seek in the phone book to Farley, the Farleys you have are ordered by FirstName, these seek operations return the data ordered by the next field. This order is SalesOrderID, even though you didn’t explicitly put that column in the index definition. The result is two datasets that are ordered by SalesOrderID, making them very mergeable. Another example is the simple query SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276; This one prefers a Hash Match to a standard lookup even! This isn’t just ordinary index intersection, this is something else again! Just like before, we could imagine it better with two whole tables, but we shouldn’t try to distinguish between joining two tables and joining two indexes. The Query Optimizer can see (using basic maths) that it’s worth doing these particular operations using these two less-than-ideal indexes (because of course, the best indexese would be on both columns – a composite such as (SalesPersonID, CustomerID – and it would have the SalesOrderID column as part of it as the CIX key still). You need to think like this too. Not in terms of excusing single-column indexes like the ones in AdventureWorks2012, but in terms of having a picture about how you’d like your queries to run. If you start to think about what data you need, where it’s coming from, and how it’s going to be used, then you will almost certainly write better queries. …and yes, this would include when you’re dealing with regular joins across multiples, not just against joins within single table queries.

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  • MSSQL STOREDPROC SELECTING FROM A FIELD FROM 1 TABLE USING LIKE TO CREATE MORE THAN 1 COLUM IN A DAT

    - by djshortbus
    I have a ASPX.NET DataGrid and im trying to USE a select LIKE 'X'% from a table that has 1 field called location. im trying to display the locations that start with a certain letter (example wxxx,axxx,fxxx,) in different columns in my data grid. SELECT DISTINCT LM.LOCATION AS '0 LOCATIONS' , LM.COUNTLEVEL AS 'COUNTLEVEL' FROM SOH S WITH(NOLOCK) JOIN LOCATIONMASTER LM ON LM.LMID = S.LMID WHERE LM.COUNTLEVEL = 1 AND LM.LOCATION NOT IN ('RECOU','PROBLEM','TOSTOCK','PYXVLOC') AND LM.LOCATION LIKE '0%' SELECT DISTINCT LM.LOCATION AS 'A LOCATIONS' , LM.COUNTLEVEL AS 'COUNTLEVEL' FROM SOH S WITH(NOLOCK) JOIN LOCATIONMASTER LM ON LM.LMID = S.LMID WHERE LM.COUNTLEVEL = 1 AND LM.LOCATION NOT IN ('RECOU','PROBLEM','TOSTOCK','PYXVLOC') AND LM.LOCATION LIKE 'A%'

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  • Need SQL Server Stored Procedure for This Query

    - by djshortbus
    I have a ASPX.NET DataGrid and im trying to USE a select LIKE 'X'% from a table that has 1 field called location. im trying to display the locations that start with a certain letter (example wxxx,axxx,fxxx,) in different columns in my data grid. SELECT DISTINCT LM.LOCATION AS '0 LOCATIONS' , LM.COUNTLEVEL AS 'COUNTLEVEL' FROM SOH S WITH(NOLOCK) JOIN LOCATIONMASTER LM ON LM.LMID = S.LMID WHERE LM.COUNTLEVEL = 1 AND LM.LOCATION NOT IN ('RECOU','PROBLEM','TOSTOCK','PYXVLOC') AND LM.LOCATION LIKE '0%' SELECT DISTINCT LM.LOCATION AS 'A LOCATIONS' , LM.COUNTLEVEL AS 'COUNTLEVEL' FROM SOH S WITH(NOLOCK) JOIN LOCATIONMASTER LM ON LM.LMID = S.LMID WHERE LM.COUNTLEVEL = 1 AND LM.LOCATION NOT IN ('RECOU','PROBLEM','TOSTOCK','PYXVLOC') AND LM.LOCATION LIKE 'A%'

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  • Need SQL Server Stored Procedure for This Query

    - by djshortbus
    I have a ASPX.NET DataGrid and im trying to USE a select LIKE 'X'% from a table that has 1 field called location. im trying to display the locations that start with a certain letter (example wxxx,axxx,fxxx,) in different columns in my data grid. SELECT DISTINCT LM.LOCATION AS '0 LOCATIONS' , LM.COUNTLEVEL AS 'COUNTLEVEL' FROM SOH S WITH(NOLOCK) JOIN LOCATIONMASTER LM ON LM.LMID = S.LMID WHERE LM.COUNTLEVEL = 1 AND LM.LOCATION NOT IN ('RECOU','PROBLEM','TOSTOCK','PYXVLOC') AND LM.LOCATION LIKE '0%' SELECT DISTINCT LM.LOCATION AS 'A LOCATIONS' , LM.COUNTLEVEL AS 'COUNTLEVEL' FROM SOH S WITH(NOLOCK) JOIN LOCATIONMASTER LM ON LM.LMID = S.LMID WHERE LM.COUNTLEVEL = 1 AND LM.LOCATION NOT IN ('RECOU','PROBLEM','TOSTOCK','PYXVLOC') AND LM.LOCATION LIKE 'A%'

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  • File corrupted by some tools (probably virus or antivirus)- does the pattern indicate any known corruptions?

    - by StackTrace
    As part of our software we install postgres(windows). In one of the customer sites, a set of files got corrupted. All files were part of timezone information(postgres/share/timezone). They are some sort of binary files. After the corruption, they all starts with following pattern od -tac output $ od -tac GMT 0000000 can esc etx sub nak dle em | nl em so | o r l _ 030 033 003 032 025 020 031 | \n 031 016 | o r l _ 0000020 \ \ \ \ \ \ \ del 3 fs ] del del del del del \ \ \ \ \ \ \ 377 3 034 ] 377 377 377 377 377 0000040 > ack r v s ack p soh q h r s q w h q 276 206 362 366 363 206 360 201 361 350 362 363 361 367 350 361 0000060 t r ack h eot s } v h | etx p eot ack nul } 364 362 206 350 204 363 375 366 350 374 203 360 204 206 200 375 0000100 | q t s t 8 E E E E E E E E E E 374 361 364 363 364 270 305 305 305 305 305 305 305 305 305 305 0000120 E E E E E E E E E E E E E E E E 305 305 305 305 305 305 305 305 305 305 305 305 305 305 305 305 * 0000240 m ; z dc3 7 sub c can em a u 5 can d 2 B 355 ; z 023 267 232 343 230 031 a u 5 230 d 262 302 0000260 X nul y J o S - 9 ] stx soh L can 1 ! j 330 \0 y 312 o S 255 9 335 202 001 314 030 261 241 j 0000300 dle g o etb n ff em ] 9 F ' dc4 } , em $ 020 g 357 227 n \f 231 ] 271 F 247 024 375 254 231 244 0000320 Q si ff L bs 2 # stx i 5 r % | | c del Q 017 214 314 210 2 # 002 351 5 362 245 374 374 343 177 0000340 m C esc H em enq ~ X o V p / l dc3 N sp m C 033 H 031 205 376 X o 326 360 257 l 023 N 0000360 } ) enq ( syn ! 3 s $ E z dc3 A dc3 ff P

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  • IIS SMTP unable to relay for domain on local network.

    - by MartinHN
    Hi I have a network with the following servers: EXCH01 - Exchange Server for @domain.com e-mails. TEST-REP01 - Local reporting server. Have IIS SMTP installed and configured. What happens on the TEST-REP01, is that I have a Windows Service that reads reports in a SQL server that is ready for delivery. All reports is sent one at a time, using the local SMTP server. It works perfectly, unless the recipient e-mail address is [email protected] - the domain that the EXCH01 server manages. I get the following error: Mailbox unavailable. The server response was: 5.7.1 Unable to relay for [email protected] What can I do to troubleshoot this further? I can't seem to find useful information in the SMTP log: 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 EHLO - +TEST-REP01 250 0 210 15 0 SMTP - - - - 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 MAIL - +FROM:<[email protected]> 250 0 44 31 0 SMTP - - - - 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 RCPT - +TO:<[email protected]> 550 0 50 28 0 SMTP - - - - 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 QUIT - TEST-REP01 240 0 50 28 0 SMTP - - - - 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 EHLO - +TEST-REP01 250 0 210 15 0 SMTP - - - - 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 MAIL - +FROM:<[email protected]> 250 0 44 31 0 SMTP - - - - 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 RCPT - +TO:<[email protected]> 550 0 50 28 0 SMTP - - - - 2011-01-05 03:01:38 192.168.8.168 TEST-REP01 SMTPSVC1 TEST-REP01 192.168.8.168 0 QUIT - TEST-REP01 240 0 50 28 0 SMTP - - - - Relay access on the local IIS (TEST-REP01) are set to allow 127.0.0.1, TEST-REP01 and other servers such as TEST-WEB01. DNS settings on the local network is not domain.com - but companyname-domain.local.

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  • Use sed command to replace , appearing between numbers

    - by Saurabh
    I have a CSV file where data are in the following format |001|,|abc,def|,123456,789,|aaa|,|bbb|,444,555,666 I want to replace only those "," that appears between numbers with some other character like say SOH or $ or * other "," appearing in the line should not get replaced i.e. to say I wish to have following output |001|,|abc,def|,123456*789,|aaa|,|bbb|,444*555*666 Can someone please help me with sed command pattern to get the above desired output

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  • Getting n-th line of text output

    - by syker
    I have a script that generates two lines as output each time. I'm really just interested in the second line. Moreover I'm only interested in the text that appears between a pair of #'s on the second line. Additionally, between the hashes, another delimiter is used: ^A. It would be great if I can also break apart each part of text that is ^A-delimited (Note that ^A is SOH special character and can be typed by using Ctrl-A)

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  • How modify ascii table in C?

    - by drigoSkalWalker
    like this: My ASCII Chart 0 1 2 3 4 5 6 7 8 9 A B C D E F 0 NUL SOH STX ETX EOT ENQ ACK BEL BS HT LF VT FF CR SO SI 1 DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US 2 SP ! " # $ % & ' ( ) * + , - . / 3 0 1 2 3 4 5 6 7 8 9 : ; ? 4 @ A B C D E F G H I J K L M N O 5 P Q R S T U V W X Y Z [ \ ] ^ _ 6 ` a b c d e f g h i j k l m n o 7 p q r s t u v w x y z { | } ~ DEL I want to call a function, alter the ascii sequence in this function and when it return, the ascii sequence back to the original. thanks in advance!

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  • C Newbie, ascii control function

    - by user570607
    Hey there, I have written a program that works well in C that converts non-readable ASCII to their character values. I would appreciate if a C master? would show me a better way of doing it that I have currently done, mainly this section: if (isascii(ch)) { switch (ch) { case 0: printControl("NUL"); break; case 1: printControl("SOH"); break; .. etc (32 in total) case default: putchar(ch); break; } } Is it normal to make a switch that big? Or should I be using some other method (input from an ascii table?)

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  • How to modify ASCII table in C ? [closed]

    - by drigoSkalWalker
    Like this: My ASCII Chart 0 1 2 3 4 5 6 7 8 9 A B C D E F 0 NUL SOH STX ETX EOT ENQ ACK BEL BS HT LF VT FF CR SO SI 1 DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US 2 SP ! " # $ % & ' ( ) * + , - . / 3 0 1 2 3 4 5 6 7 8 9 : ; ? 4 @ A B C D E F G H I J K L M N O 5 P Q R S T U V W X Y Z [ \ ] ^ _ 6 ` a b c d e f g h i j k l m n o 7 p q r s t u v w x y z { | } ~ DEL I want to call a function, alter the ASCII sequence in this function and when it returns, the ASCII sequence back to the original. Thanks in advance! EDIT: What I want is it: I want to change the order of chars, for examble, A is 65, if I want to make A equal a 0? without to make a function to do it, for example, I could accomplish it with a function that compare an array of chars, and store it in another way with the correct value (the new table), but do it is too expensive, is there another way? thanks in advance again!

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  • Jquery Automatic Image Slider w/ CSS & jQuery

    - by Jacinto
    This is Automatic Image Slider w/ CSS & jQuery by Soh Tanaka I am trying to customize it to show .desc when the mouse hover overs the slider but it does not seem to work any help? //Set Default State of each portfolio piece $(".paging").show(); $(".paging a:first").addClass("active"); //Get size of images, how many there are, then determin the size of the image reel. var imageWidth = $(".window").width(); var imageSum = $(".image_reel ul.examples").size(); var imageReelWidth = imageWidth * imageSum; //Adjust the image reel to its new size $(".image_reel").css({'width' : imageReelWidth}); //Paging + Slider Function rotate = function(){ var triggerID = $active.attr("rel") - 1; //Get number of times to slide var image_reelPosition = triggerID * imageWidth; //Determines the distance the image reel needs to slide $(".paging a").removeClass('active'); //Remove all active class $active.addClass('active'); //Add active class (the $active is declared in the rotateSwitch function) //Slider Animation $(".image_reel").animate({ left: -image_reelPosition }, 500 ); }; //Rotation + Timing Event rotateSwitch = function(){ play = setInterval(function(){ //Set timer - this will repeat itself every 3 seconds $active = $('.paging a.active').next(); if ( $active.length === 0) { //If paging reaches the end... $active = $('.paging a:first'); //go back to first } rotate(); //Trigger the paging and slider function }, 7000); //Timer speed in milliseconds (3 seconds) }; rotateSwitch(); //Run function on launch //On Hover $(".image_reel").hover(function() { clearInterval(play); //Stop the rotation }, function() { rotateSwitch(); //Resume rotation }); //Hide the tooglebox when page load $(".desc").hide(); //slide up and down when hover over heading 2 $(".image_reel").hover(function(){ // slide toggle effect set to slow you can set it to fast too. $(this).next(".desc").slideToggle("slow"); return true; }); //On Click $(".paging a").click(function() { $active = $(this); //Activate the clicked paging //Reset Timer clearInterval(play); //Stop the rotation rotate(); //Trigger rotation immediately rotateSwitch(); // Resume rotation return false; //Prevent browser jump to link anchor });

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  • drop down menu will not display outside containing div in IE7..

    - by playahabana
    I am tearing my hair out over this, I have a dropdown menu using CSS and jQuery (thanks to Soh Tanaka) and it works perfectly in Firefox, Safari, Google chrome and I.E. 8, but in IE 7 it will not drop down outside the 'Banner div'. It drops below the nav div however. I have moved the nav div higher in the banner the result is the same, menu drops until it reaches the border of the banner div and then vanishes.... Below is the css. This is my first website and I have some limited understanding of what I am doing. The drop down menu includes transparent png's as links (I know, I know...but it's what the Boss wants...) please could someone take a quick scan at the below CSS and let me know what is wroong? Is this some form of the IE z-index bug? i have tried all different combinations of z-index and still I can't get a different result. . The html is below as well. Thankyou in advance #banner { position: relative; width: 62.5em; height: 12em; background-color: #46280A; background-image: url('images/includes/banner2.jpg'); background-repeat: no-repeat; background-position: center; -moz-box-shadow: -4px 6px 8px #000; -webkit-box-shadow: -4px 6px 8px #000; box-shadow: -4px 6px 8px #000; /* For IE 8 */ -ms-filter: "progid:DXImageTransform.Microsoft.Shadow(Strength=8, Direction=225, Color='#000000')"; /* For IE 5.5 - 7 */ filter: progid:DXImageTransform.Microsoft.Shadow(Strength=8, Direction=225, Color='#000000'); z-index: 1; } /*------------------------------------SCROLLER---------------------------------------------*/ #headlines{ position: absolute; top: 1.3em; right: 2.75em; overflow: hidden; height: 2.5em; width: 24em; background-color: #000000; display: block; z-index: 3; } #news{ position: relative; height: 3.1em; line-height: 2.5em; font-size: 0.8em color: #FFFF99; white-space: nowrap; overflow: hidden; font-family: Georgia,Arial; } #scrollerglass{ position: absolute; top: 0.95em; right: 2em; height: 52px; width: 410px; border: none; padding: 0.2em 0em 0em 0em; line-height: 0.7em; text-align: center; background-image: url('images/includes/scrollerglass.png'); background-color: transparent; background-repeat: no-repeat; background-position: center; opacity: 20; z-index: 10; } #scrollerglass a i { visibility: hiddn ; } /-------------------------------------NAVIGATION-----------------------------------------/ #nav { position: absolute; top: 5.8em; left: 0.2em; font-family: trebuchet, sans-serif; font-size: 1em; line-height: 3.75em; text-align: center; color: #FFFF00; z-index: 3; } ul.navlist { list-style: none; padding: 0em; margin: 1em; float: left; width: 62.5em; background: transparent; font-size: 1em; } ul.navlist li { position: relative; /*--Declare X and Y axis base for sub navigation--*/ float: left; margin: 0em 1.4em; padding: 0em 0.7em 0em 0em; z-index: 1; } ul.navlist li a{ display: block; text-decoration: none; float: left; border: 0px solid; } ul.navlist li img{ border: 0px solid; } ul.navlist li span { trigger styles--*/ width: 1.2em; height: 5.25em; float: left; background: url(images/links/downlogo.png) no-repeat center top; } ul.navlist li span.subhover { background-position: center bottom; cursor: pointer; } ul.navlist li ul.navdrop { list-style: none; position: absolute; float: left; top: 5.3em; left: -2.4em; height: 15.0em; width: 11.25em; margin: 0; padding: 0.5em 0em 0em 0em; display: none; background-position: center; background-image: url('images/includes/slider.jpg'); background-color: transparent; background-repeat: no-repeat; -moz-box-shadow: -4px 6px 8px #000; -webkit-box-shadow: -4px 6px 8px #000; box-shadow: -4px 6px 8px #000; /* For IE 8 */ -ms-filter: "progid:DXImageTransform.Microsoft.Shadow(Strength=8, Direction=225, Color='#000000')"; /* For IE 5.5 - 7 */ filter: progid:DXImageTransform.Microsoft.Shadow(Strength=8, Direction=225, Color='#000000'); z-index:1; } ul.navlist li ul.navdrop li{ margin: 0em 2.3em 0em 0em; padding: 1em 0em 0em 0em; width: 8em; clear: both; } html ul.navlist li ul.navdrop li a { border: 0px solid; width: 11.25em; } html ul.navlist li ul.navdrop li a:hover { background: transparent; } <div id="banner"> <div id="headlines"> <div id="news"> Whatever we want to promote </div> </div> <div id="scrollerglass"> <a href="vintagecigars.php"> <i>------s-c-r-o-l-l-e-r - - - -l-i-n-k-s--------<br /> <br>------s-c-r-o-l-l-e-r - - - -l-i-n-k-s------</i></a> </div> <div id="nav"> <ul class="navmenu"> <li><a href="index.php"><img src="images/links/home.png" alt="Home" ></a></li> <li><a href="ourbar.php"><img src="images/links/ourbar.png" alt="Our Bar" ></a> <ul class="navdrop"> <li ><a href="ourcocktails.php"><img src="images/links/cockteles.png" alt="Our Cocktails" ></a></li> <li ><a href="celebrate.php"><img src="images/links/celebrate.png" alt="Celebrate in Style" ></a></li> </ul> </li> <li><a href="ourcigars.php"><img src="images/links/ourcigars.png" alt="Our Cigars" ></a> <ul class="navdrop"> <li ><a href="edicioneslimitadas.php"><img src="images/links/edicioneslimitadas.png" alt="Edition Limitadas" ></a></li> <li ><a href="cigartasting.php"><img src="images/links/cigartasting.png" alt="Cigar Tastings" ></a></li> </ul> </li> <li><a href="personalroller.php"><img src="images/links/personalcigar.png" alt="Personal Cigar Roller" ></a></li> <li><a href="galleryentrance.php"><img src="images/links/photogallery.png" alt="Photo Gallery" ></a></li> <li><a href="contactus.php"><img src="images/links/contactus.png" alt="Contact Us" ></a></li> </ul></div></div><!--end banner-->

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