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  • Question about Cost in Oracle Explain Plan

    - by Will
    When Oracle is estimating the 'Cost' for certain queries, does it actually look at the amount of data (rows) in a table? For example: If I'm doing a full table scan of employees for name='Bob', does it estimate the cost by counting the amount of existing rows, or is it always a set cost?

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  • ASP.NET MVC Deployed Application Server Address

    - by Jacob Huggart
    I have an application that sends an email to a user so that they may access a web form. In the email there is just a link to the start page of this form. Currently, I have the value for the form location hardcoded. Once the app is deployed I know it is in inetpub/wwwroot/appName, which results in a URL of serverip:appPort/appName. What is the C# to get the serverip:appPort portion of the URL that I need? I think that server.mappath() might work, but for some reason I can't get to the method even though I have the necessary references.

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  • Acceessing some aggregate functions in a linq datasource in a GridView

    - by Stephen Pellicer
    I am working on a traditional WebForms project. In the project I am trying out some Linq datasources with plans to eventually migrate to an MVC architecture. I am still very new to Linq. I have a GridView using a Linq datasource. The entities I am showing has a to many relationship and I would like to get the maximum value of a column in the many side of the relationship. I can show properties of the base entity in the gridview: <asp:TemplateField HeaderText="Number" SortExpression="tJobBase.tJob.JobNumber"> <ItemTemplate> <asp:Label ID="Label1" runat="server" Text='<%# Bind("tJobBase.tJob.JobNumber") %>'> </asp:Label> </ItemTemplate> </asp:TemplateField> I can also show the count of the many related property: <asp:TemplateField HeaderText="Number" SortExpression="tJobBase.tJob.tHourlies.Count"> <ItemTemplate> <asp:Label ID="Label1" runat="server" Text='<%# Bind("tJobBase.tJob.tHourlies.Count") %>'> </asp:Label> </ItemTemplate> </asp:TemplateField> Is there a way to get the max value of a column called WeekEnding in the tHourlies collection to show in the GridView?

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  • Is it possible to have a tableless select with multiple rows?

    - by outis
    A SELECT without a FROM clause gets us a multiple columns without querying a table: SELECT 17+23, REPLACE('bannanna', 'nn', 'n'), RAND(), CURRENT_TIMESTAMP; How can we write a query that results in multiple rows without referring to a table? Basically, abuse SELECT to turn it into a data definition statement. The result could have a single column or multiple columns. I'm most interested in a DBMS neutral answer, but others (e.g. based on UNPIVOT) are welcome. There's no technique application behind this question; it's more theoretical than practical.

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  • how to design a schema where the columns of a table are not fixed

    - by hIpPy
    I am trying to design a schema where the columns of a table are not fixed. Ex: I have an Employee table where the columns of the table are not fixed and vary (attributes of Employee are not fixed and vary). Nullable columns in the Employee table itself i.e. no normalization Instead of adding nullable columns, separate those columns out in their individual tables ex: if Address is a column to be added then create table Address[EmployeeId, AddressValue]. Create tables ExtensionColumnName [EmployeeId, ColumnName] and ExtensionColumnValue [EmployeeId, ColumnValue]. ExtensionColumnName would have ColumnName as "Address" and ExtensionColumnValue would have ColumnValue as address value. Employee table EmployeeId Name ExtensionColumnName table ColumnNameId EmployeeId ColumnName ExtensionColumnValue table EmployeeId ColumnNameId ColumnValue There is a drawback is the first two ways as the schema changes with every new attribute. Note that adding a new attribute is frequent. I am not sure if this is the good or bad design. If someone had a similar decision to make, please give an insight on things like foreign keys / data integrity, indexing, performance, reporting etc.

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  • How to consolidate multiple LOG files into one .LDF file in SQL2000

    - by John Galt
    Here is what sp_helpfile says about my current database (recovery model is Simple) in SQL2000: name fileid filename size maxsize growth usage MasterScratchPad_Data 1 C:\SQLDATA\MasterScratchPad_Data.MDF 6041600 KB Unlimited 5120000 KB data only MasterScratchPad_Log 2 C:\SQLDATA\MasterScratchPad_Log.LDF 2111304 KB Unlimited 10% log only MasterScratchPad_X1_Log 3 E:\SQLDATA\MasterScratchPad_X1_Log.LDF 191944 KB Unlimited 10% log only I'm trying to prepare this for a detach then an attach to a sql2008 instance but I don't want to have the 2nd .LDF file (I'd like to have just one file for the log). I have backed up the database. I have issued: BACKUP LOG MasterScratchPad WITH TRUNCATE_ONLY. I have run multiple DBCC SHRINKFILE commands on both of the LOG files. How can I accomplish this goal of having just one .LDF? I cannot find anything on how to delete the one with fileid of 3 and/or how to consolidate multiple files into one log file.

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  • How do I write this MySQL query?

    - by CT
    I am working on an Asset DB using a lamp stack. In this example consider the following 5 tables: asset, server, laptop, desktop, software All tables have a primary key of id, which is a unique asset id. Every object has all asset attributes and then depending on type of asset has additional attributes in the corresponding table. If the type is a server, desktop or laptop it also has items in the software table. Here are the table create statements: // connect to mysql server and database "asset_db" mysql_connect("localhost", "asset_db", "asset_db") or die(mysql_error()); mysql_select_db("asset_db") or die(mysql_error()); // create asset table mysql_query("CREATE TABLE asset( id VARCHAR(50) PRIMARY KEY, company VARCHAR(50), location VARCHAR(50), purchase_date VARCHAR(50), purchase_order VARCHAR(50), value VARCHAR(50), type VARCHAR(50), notes VARCHAR(200))") or die(mysql_error()); echo "Asset Table Created.</br />"; // create software table mysql_query("CREATE TABLE software( id VARCHAR(50) PRIMARY KEY, software VARCHAR(50), license VARCHAR(50))") or die(mysql_error()); echo "Software Table Created.</br />"; // create laptop table mysql_query("CREATE TABLE laptop( id VARCHAR(50) PRIMARY KEY, manufacturer VARCHAR(50), model VARCHAR(50), serial_number VARCHAR(50), esc VARCHAR(50), user VARCHAR(50), prev_user VARCHAR(50), warranty VARCHAR(50))") or die(mysql_error()); echo "Laptop Table Created.</br />"; // create desktop table mysql_query("CREATE TABLE desktop( id VARCHAR(50) PRIMARY KEY, manufacturer VARCHAR(50), model VARCHAR(50), serial_number VARCHAR(50), esc VARCHAR(50), user VARCHAR(50), prev_user VARCHAR(50), warranty VARCHAR(50))") or die(mysql_error()); echo "Desktop Table Created.</br />"; // create server table mysql_query("CREATE TABLE server( id VARCHAR(50) PRIMARY KEY, manufacturer VARCHAR(50), model VARCHAR(50), warranty VARCHAR(50))") or die(mysql_error()); echo "Server Table Created.</br />"; ?> How do I query the database so that if I search by id, I receive all related fields to that asset id? Thank you.

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  • Returning IEnumerable<T> vs IQueryable<T>

    - by stackoverflowuser
    what is the difference between returning iqueryable vs ienumerable. IQueryable<Customer> custs = from c in db.Customers where c.City == "<City>" select c; IEnumerable<Customer> custs = from c in db.Customers where c.City == "<City>" select c; Will both be deferred execution? When should one be preferred over the other?

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  • Simple Database normalization question...

    - by user365531
    Hi all, I have a quick question regarding a database that I am designing and making sure it is normalized... I have a customer table, with a primary key of customerId. It has a StatusCode column that has a code which reflects the customers account status ie. 1 = Open, 2 = Closed, 3 = Suspended etc... Now I would like to have another field in the customer table that flags whether the account is allowed to be suspended or not... certain customers will be automatically suspended if they break there trading terms... others not... so the relevant table fields will be as so: Customers (CustomerId(PK):StatusCode:IsSuspensionAllowed) Now both fields are dependent on the primary key as you can not determine the status or whether suspensions are allowed on a particular customer unless you know the specific customer, except of course when the IsSuspensionAllowed field is set to YES, the the customer should never have a StatusCode of 3 (Suspended). It seems from the above table design it is possible for this to happen unless a check contraint is added to my table. I can't see how another table could be added to the relational design to enforce this though as it's only in the case where IsSuspensionAllowed is set to YES and StatusCode is set to 3 when the two have a dependence on each other. So after my long winded explanation my question is this: Is this a normalization problem and I'm not seeing a relational design that will enforce this... or is it actually just a business rule that should be enforced with a check contraint and the table is in fact still normalized. Cheers, Steve

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  • Does the optimizer filter subqueries with outer where clauses

    - by Mongus Pong
    Take the following query: select * from ( select a, b from c UNION select a, b from d ) where a = 'mung' Will the optimizer generally work out that I am filtering a on the value 'mung' and consequently filter mung on each of the queries in the subquery. OR will it run each query within the subquery union and return the results to the outer query for filtering (as the query would perhaps suggest) In which case the following query would perform better : select * from ( select a, b from c where a = 'mung' UNION select a, b from d where a = 'mung' ) Obviously query 1 is best for maintenance, but is it sacrificing much performace for this? Which is best?

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  • TSQL: grouping customer orders by week

    - by fishhead
    I have a table with a collection of orders. The fields are: customerName (text) DateOfOrder (datetime). I would like to show totals of orders per week per customer. I would like to have it arranged for the Friday of each week so that it looks like this: all dates follow mm/dd/yyyy "bobs pizza", 3/5/2010, 10 "the phone co",3/5/2010,5 "bobs pizza", 3/12/2010, 3 "the phone co",3/12/2010,11 Could somebody please show me how to do this? Thanks

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  • Properly populating tables in an Object Relational database

    - by chaosTechnician
    I've got a homework assignment that requires that I use Oracle 10g Express to implement an Object Relational database to track phone billing data. I have a superclass of Communications with subclasses of Call, Text, and Data. I'm hitting a snag with properly populating these tables so that I can find the appropriate data in the various tables. My Types and Tables are declared as such: create type CommunicationType as object ( -- column names here ) not final; create type CallType under CommunicationType ( -- column names here ); create type TextType under CommunicationType ( -- column names here ); create type DataType under CommunicationType ( -- column names here ); create table Communications of CommunicationType ( -- Primary and Foreign key constraints here ); create table Calls of CallType; create table Texts of TextType; create table Datas of DataType; When I try to insert data into one of the subclasses, its entry doesn't appear in the superclass. Likewise if I insert into the superclass, it doesn't show up in the appropriate subclass. For example, insert into Calls values (CallType( -- Values -- )); doesn't show any data in Communications. Nor does insert into Communications values (CallType( -- Values -- )); show anything in Calls. What am I doing wrong?

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  • Oracle database connection string PLSQL compatibility

    - by user521180
    Hi I'm using an application called Logi info. it requires a connection string to my oracle database. the connection works fine but in order to configure the connection to recive ref cursors from the database, I apparently need to add PLSQLRSet=1 to the end of the string. when I do that I recieve an error "invalid connection string" Here is my connection string without plsqlrset=1 Data Source=SID; User Id=username; Password=password; My concern is that PLSQLRSet=1 might be .NET paramater only. Can anyone shed some light on the issue. Thanks

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  • Oracle Stored Procedure with Alter command

    - by Will
    Hello, I am trying to build an oracle stored procedure which will accept a table name as a parameter. The procedure will then rebuild all indexes on the table. My problem is I get an error while using the ALTER command from a stored procedure, as if PLSQL does not allow that command.

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  • postgresql is incrementing an update by 2 ?

    - by John Tyler
    I'm migrating our model to postgresql for the FTS and data integrity update myschema.counters set counter_count= (counter_count+1) where counter_id =? Works as expected in mysql, however in postgres it is incrementing by 2 each time? It is simple int field I believe, I don't have anything special going on.

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  • linq join query

    - by SamB09
    Hi, im trying to do a join in linq , however for some reason i cant access the primary key of a table. It's the 'h.ProjectId' that doesn't seem to be accepted. The following error is given CW1.SearchWebService.Bid does not contain a definition for 'ProjectId' and no extention method 'ProjectId' accepting a first argument of type 'CW1SearchWebService.Bid' var allProjects = ctxt.Project.ToList() ; var allBids = ctxt.Bid.ToArray();// return all bids var projects = (from project in allProjects join h in allBids on project.ProjectId equals h.ProjectId

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  • Computed column should result to string

    - by strakastroukas
    Here is a snap of my database. Both col1 and col2 are declared as int. My ComputedColumn currently adds the Columns 1 and 2, as follows... col1 col2 ComputedColumn 1 2 3 4 1 5 Instead of this, my ComputedColumn should join the columns 1 and 2 (includimg the '-' character in the middle) as follows... col1 col2 ComputedColumn 1 2 1-2 4 1 4-1 So, what is the correct syntax?

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  • Database layout tagging system

    - by Kurresmack
    I am creating a web site for a customer and they want to be able to create articles. My idea is to tag them so I am going to implement the system. What is the best design, both from an architectural and a perfomance perspective: 1. To have table with all tags and then have a one to many relationship table that links a tag like this: articles table with ID tags table with ID one to many table with columns Article.ID and Tags.ID 2. To have one table with articles and one with tags for articles like this: articles table with ID tags table with Article.ID and tag text Thanks in advance!

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  • mysql whats wrong with this query?

    - by Hailwood
    I'm trying to write a query that selects from four tables campaignSentParent csp campaignSentEmail cse campaignSentFax csf campaignSentSms css Each of the cse, csf, and css tables are linked to the csp table by csp.id = (cse/csf/css).parentId The csp table has a column called campaignId, What I want to do is end up with rows that look like: | id | dateSent | emailsSent | faxsSent | smssSent | | 1 | 2011-02-04 | 139 | 129 | 140 | But instead I end up with a row that looks like: | 1 | 2011-02-03 | 2510340 | 2510340 | 2510340 | Here is the query I am trying SELECT csp.id id, csp.dateSent dateSent, COUNT(cse.parentId) emailsSent, COUNT(csf.parentId) faxsSent, COUNT(css.parentId) smsSent FROM campaignSentParent csp, campaignSentEmail cse, campaignSentFax csf, campaignSentSms css WHERE csp.campaignId = 1 AND csf.parentId = csp.id AND cse.parentId = csp.id AND css.parentId = csp.id; Adding GROUP BY did not help, so I am posting the create statements. csp CREATE TABLE `campaignsentparent` ( `id` int(11) NOT NULL AUTO_INCREMENT, `campaignId` int(11) NOT NULL, `dateSent` datetime NOT NULL, `account` int(11) NOT NULL, `status` varchar(15) NOT NULL DEFAULT 'Creating', PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=latin1 cse/csf (same structure, different names) CREATE TABLE `campaignsentemail` ( `id` int(11) NOT NULL AUTO_INCREMENT, `parentId` int(11) NOT NULL, `contactId` int(11) NOT NULL, `content` text, `subject` text, `status` varchar(15) DEFAULT 'Pending', PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=140 DEFAULT CHARSET=latin1 css CREATE TABLE `campaignsentsms` ( `id` int(11) NOT NULL AUTO_INCREMENT, `parentId` int(11) NOT NULL, `contactId` int(11) NOT NULL, `content` text, `status` varchar(15) DEFAULT 'Pending', PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=141 DEFAULT CHARSET=latin1

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  • Deeply nested subqueries for traversing trees in MySQL

    - by nickf
    I have a table in my database where I store a tree structure using the hybrid Nested Set (MPTT) model (the one which has lft and rght values) and the Adjacency List model (storing parent_id on each node). my_table (id, parent_id, lft, rght, alias) This question doesn't relate to any of the MPTT aspects of the tree but I thought I'd leave it in in case anyone had a good idea about how to leverage that. I want to convert a path of aliases to a specific node. For example: "users.admins.nickf" would find the node with alias "nickf" which is a child of one with alias "admins" which is a child of "users" which is at the root. There is a unique index on (parent_id, alias). I started out by writing the function so it would split the path to its parts, then query the database one by one: SELECT `id` FROM `my_table` WHERE `parent_id` IS NULL AND `alias` = 'users';-- 1 SELECT `id` FROM `my_table` WHERE `parent_id` = 1 AND `alias` = 'admins'; -- 8 SELECT `id` FROM `my_table` WHERE `parent_id` = 8 AND `alias` = 'nickf'; -- 37 But then I realised I could do it with a single query, using a variable amount of nesting: SELECT `id` FROM `my_table` WHERE `parent_id` = ( SELECT `id` FROM `my_table` WHERE `parent_id` = ( SELECT `id` FROM `my_table` WHERE `parent_id` IS NULL AND `alias` = 'users' ) AND `alias` = 'admins' ) AND `alias` = 'nickf'; Since the number of sub-queries is dependent on the number of steps in the path, am I going to run into issues with having too many subqueries? (If there even is such a thing) Are there any better/smarter ways to perform this query?

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  • Why index_merge is not used here using MySQL?

    - by user198729
    Setup: mysql> create table t(a integer unsigned,b integer unsigned); mysql> insert into t(a,b) values (1,2),(1,3),(2,4); mysql> create index i_t_a on t(a); mysql> create index i_t_b on t(b); mysql> explain select * from t where a=1 or b=4; +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | t | ALL | i_t_a,i_t_b | NULL | NULL | NULL | 3 | Using where | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ Is there something I'm missing? Update mysql> explain select * from t where a=1 or b=4; +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | t | ALL | i_t_a,i_t_b | NULL | NULL | NULL | 1863 | Using where | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ Version: mysql> select version(); +----------------------+ | version() | +----------------------+ | 5.1.36-community-log | +----------------------+

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  • Using subselect to accomplish LEFT JOIN

    - by Andre
    Is is possible to accomplish the equivalent of a LEFT JOIN with subselect where multiple columns are required. Here's what I mean. SELECT m.*, (SELECT * FROM model WHERE id = m.id LIMIT 1) AS models FROM make m As it stands now doing this gives me a 'Operand should contain 1 column(s)' error. Yes I know this is possible with LEFT JOIN, but I was told it was possible with subselect to I'm curious as to how it's done.

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  • sqlite3 date and interval functions

    - by umuthorax
    Hi, I wonder whether sqlite3 supports interval function. The following statement is accepted by PostgreSQL, however sqlite3 failed to parse it; select ... from orders where ... and o_orderdate < date '1995-03-01' + interval '3' month Error: near line 4: near "'1995-03-01'": syntax error Then, I modified the statement a little bit such as; and o_orderdate < date('1995-03-01') + interval '3' month This time the error was; Error: near line 4: near "'3'": syntax error Unfortunately, same trick did not work for the interval function i.e. and o_orderdate < date('1995-03-01') + interval('3' month) or and o_orderdate < date('1995-03-01') + interval('3') month or even and o_orderdate < date('1995-03-01') + interval(3 month) still gave me the syntax error. Maybe sqlite3 does not support interval function or am I missing something in its usage? Thanks a lot

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