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  • implementing dynamic query handler on historical data

    - by user2390183
    EDIT : Refined question to focus on the core issue Context: I have historical data about property (house) sales collected from various sources in a centralized/cloud data source (assume info collection is handled by a third party) Planning to develop an application to query and retrieve data from this centralized data source Example Queries: Simple : for given XYZ post code, what is average house price for 3 bed room house? Complex: What is estimated price for an house at "DD,Some Street,XYZ Post Code" (worked out from average values of historic data filtered by various characteristics of the house: house post code, no of bed rooms, total area, and other deeper insights like house building type, year of built, features)? In addition to average price, the application should support other property info ** maximum, or minimum price..etc and trend (graph) on a selected property attribute over a period of time**. Hence, the queries should not enforce the search based on a primary key or few fixed fields In other words, queries can be What is the change in 3 Bed Room house price (irrespective of location) over last 30 days? What kind of properties we can get for X price (irrespective of location or house type) The challenge I have is identifying the domain (BI/ Data Analytical or DB Design or DB Query Interface or DW related or something else) this problem (dynamic query on historic data) belong to, so that I can do further exploration My findings so far I could be wrong on the following, so please correct me if you think so I briefly read about BI/Data Analytics - I think it is heavy weight solution for my problem and has scalability issues. DB Design - As I understand RDBMS works well if you know Data model at design time. I am expecting attributes about property or other entity (user) that am going to bring in, would evolve quickly. hence maintenance would be an issue. As I am going to have multiple users executing query at same time, performance would be a bottleneck Other options like Graph DB (http://www.tinkerpop.com/) seems to be bit complex (they are good. but using those tools meant for generic purpose, make me think like assembly programming to solve my problem ) BigData related solution are to analyse data from multiple unrelated domains So, Any suggestion on the space this problem fit in ? (Especially if you have design/implementation experience of back-end for property listing or similar portals)

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  • Oracle Database Appliance:???????????1Box?????2????????!

    - by Yusuke.Yamamoto
    11?14????????·????????Oracle Database Appliance???????????????? ????????:????????Oracle Database Appliance??????????? Oracle Database Appliance ??? Oracle Database Appliance ??Oracle Database ?????????????????????????·??????????Oracle Database ??(1)??????(2)RAC One Node ??(3)Oracle RAC ?????????????????????? Oracle Real Application Clusters(RAC)|??????????? ??????Oracle Database 11gR2 Oracle Real Application Clusters One Node ??(1)?????DB?????????????1Box???????? Oracle Database Appliance ???Oracle Real Application Clusters(RAC) ????????????DB??????????????????(????2??????????????????????????????????????????)?1Box????4U???????????????????????? ??(2)?????DB????2???????? Oracle Database Appliance ???Oracle Appliance Manager ????????????????????????Oracle Appliance Manager ????????(7????)???????????(Oracle Database?Oracle Grid Infrastructure?Oracle Enterprise Manager??)?????????(????????????????)?????????????????????2??????? ???Oracle Database Appliance ???????????????????????·????????????? Oracle Appliance Manager:????????????:7??????????????????? ??(3)????????????:???CPU???????????????????? Oracle Database Appliance ????Pay-As-You-Grow(?????????????)???????????????·????????????????Oracle Database Enterprise Edition ???????2??~24????????????? ?????????????????Oracle Database Enterprise Edition ????????(??????????????????)??????????????? Oracle Database Appliance:???? ????????????????????????????????? Oracle Database Appliance:???? ?????? Oracle Database Appliance Oracle Database Appliance:?????? Oracle Database Appliance:?????(??) Oracle Database Appliance:3D?? ????????? Oracle Direct ????Oracle Appliance Manager ????????????????????

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  • How to Link VS2010 Database Project and LINQ to SQL

    - by Jason
    As I am working with the new database projects in VS2010, and as I am learning LINQ to SQL, I am curious as to the best way to link the two groups of information so that when I update one, the other updates along with it. From my research here at SO, as well as in Google, it appears the general rule of thumb is: "Build the database, and then create your LINQ to SQL classes." Of course, if I make a change in my database, the LINQ to SQL doesn't update automatically and I have to do it by hand. This is fairly simple right now as my database is small, but I am curious if there is an easier way for this to happen. In addition, the LINQ to SQL tool is pretty nice. The ability to create tables, add associations, and even create inheritance is very simple. As my second question, I am curious as to whether or not VS2010 can work the other way - I design the database in the DBLM file and then link it back to my database project. I appreciate any help with either of these two questions. I'm really interested in making this as easy as possible to reduce errors during development and improve the speed at which changes can be made.

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  • Why use SQL database?

    - by martinthenext
    I'm not quite sure stackoverflow is a place for such a general question, but let's give it a try. Being exposed to the need of storing application data somewhere, I've always used MySQL or sqlite, just because it's always done like that. As it seems like the whole world is using these databases, most of all software products, frameworks, etc. It is rather hard for a beginning developer like me to ask a question - why? Ok, say we have some object-oriented logic in our application, and objects are related to each other somehow. We need to map this logic to the storage logic, so we need relations between database objects too. This leads us to using relational database and I'm ok with that - to put it simple, our database rows sometimes will need to have references to other tables' rows. But why do use SQL language for interaction with such a database? SQL query is a text message. I can understand this is cool for actually understanding what it does, but isn't it silly to use text table and column names for a part of application that no one ever seen after deploynment? If you had to write a data storage from scratch, you would have never used this kind of solution. Personally, I would have used some 'compiled db query' bytecode, that would be assembled once inside a client application and passed to the database. And it surely would name tables and colons by id numbers, not ascii-strings. In the case of changes in table structure those byte queries could be recompiled according to new db schema, stored in XML or something like that. What are the problems of my idea? Is there any reason for me not to write it myself and to use SQL database instead?

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  • sql query for 3 tables

    - by greffe
    i have 3 tables (A,B,C) Table A - ID Name 1 Sam 2 Manuel 3 Jane Table B ID Tab_A_ID Name 1 1 Meer 2 1 Kutti 3 2 Mikaro Table C ID Tab_B_ID Price 1 1 255.11 2 1 30.52 3 3 125.22 I need a query that shall pick up the top price for TableA-Name from TableC. So only 1 top price for 1 nae record. e.g.- Sam - 255.11 Manuel - 125.22 How can i get this?

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  • Query that ignore the spaces.

    - by xRobot
    What's the best way to run a query so that spaces in the fields are ignored? For example the following queries.... SELECT * FROM mytable WHERE username = "JohnBobJones" SELECT * FROM mytable WHERE username = "John Bob Jones" . would find the following entries: John Bob Jones JohnBob Jones JohnBobJones . I am using php or python but I think this doesn't matter.

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  • Designing a game database

    - by Ronald
    I'm trying to design a database to record game histories for a game I'm working on. I have 3 different tables: users, gamehistories, and gamescores. Columns for tables: users: uid, displayname, email gamehistories: gid, pubID, start (datetime), end (datetime) gamescores: gid, uid, score I am trying to produce the following result set given a userID (uid): Opponent's displayname, my score, opponent's score, duration Any ideas? Is my design ok? How can I query these tables to get game histories for a given uid?

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  • Synchronize a client database with the central database

    - by Pavan Kumar
    I need to update existing data or insert new data from client database say DB1 into central database say DB2 both holding same schema and both databases reside in same machine. The updates are not biderectional. I just want changes to be reflected from client(DB1) to server(DB2). How do i achieve this using C# .NET ? Can anyone provide an example ?

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  • Database tables - how many database?

    - by Thomas
    How many databases are needed for a social website? I have my tech team working on developing a social site but all their tables are in 1 database. I wanted to create separate table sets for user data, temporary tables, etc and thinking maybe have one separate database only for critical data, etc but I am not a tech person and now sure how this works? The site is going to be a local reviews website.

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  • MYSQL update query php

    - by bell
    I am trying to use an update query to change values held in a database, the new values I am trying to store are held in php variables. I'm not sure what it is I'm doing wrong. mysql_query("UPDATE user SET status='full' WHERE user_id = '$user_id'")or die(mysql_error()); thanks in advance

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  • Converting a certain SQL query into relational algebra

    - by Fumler
    Just doing an assignment for my database course and I just want to double check that I've correctly wrapped my head around relational algebra. The SQL query: SELECT dato, SUM(pris*antall) AS total FROM produkt, ordre WHERE ordre.varenr = produkt.varenr GROUP BY dato HAVING total >= 10000 The relational algebra: stotal >= 10000( ?R(dato, total)( sordre.varenr = produkt.varenr( datoISUM(pris*antall(produkt x ordre)))) Is this the correct way of doing it?

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  • What is the fastest findByName query with hibernate?

    - by Karussell
    I am sure I can improve the performance of the following findByName query of hibernate: public List<User> findByName(String name) { session.createCriteria(User.class).add(Restrictions.eq("name", name)).list(); } In which way should I improve it or even more important: in which ways should I improve it first? I will need the full object with all the collections (layz or not) and deps of this class.

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  • Wrong data retrieved from database

    - by holyredbeard
    So, I want to retrieve the order of the elements of a list. The order is set before by the user, and are stored in the table below. Because I also want to retrieve name and description of the list elements I need to combine two tables (see below). However, what is actually retrieved is an array containing 16 elements (should be four because it only exists four elements as for now). The array is too long to post here, but I put it in a phpFiddle to be found here if you're interested. Well, I have really tried to find what's wrong (probably something easy as always), but with no luck. Thanks a lot for your time and help! listModel.php: public function GetOrderedElements($userId, $listId) { // $userId = 46 // $listId = 1 $query = "SELECT le.listElemId, le.listElemName, le.listElemDesc, lo.listElemOrderPlace FROM listElement AS le INNER JOIN listElemOrder AS lo ON le.listId = lo.listId WHERE lo.userId = ? AND lo.listId = ? ORDER BY listElemId"; $stmt = $this->m_db->Prepare($query); $stmt->bind_param("ii", $userId, $listId); $listElements = $this->m_db->GetOrderedElements($stmt); return $listElements; } database.php: public function GetOrderedElements(\mysqli_stmt $stmt) { if ($stmt === FALSE) { throw new \Exception($this->mysqli->error); } if ($stmt->execute() == FALSE) { throw new \Exception($this->mysqli->error); } if ($stmt->bind_result($listElemId, $listElemName, $listElemDesc, $listElemOrderPlace) == FALSE) { throw new \Exception($this->mysqli->error); } $listElements = array(); while ($stmt->fetch()) { $listElements[] = array('listElemId' => $listElemId, 'listElemName' => $listElemName, 'listElemDesc' => $listElemDesc, 'listElemOrderPlace' => $listElemOrderPlace); } var_dump($listElements); $stmt->Close(); return $listElements; } from the database: listElemOrder: listElemOrderId | listId | listElemId | userId | listElemOrderPlace 1 1 1 46 1 2 1 2 46 4 3 1 3 46 2 4 1 4 46 3 listElement: listElemId | listElemName | listId | listElemDesc | listElemOrderPlace 1 Elem A 1 Derp NULL 2 Elem B 1 Herp NULL 3 Elem C 1 Lorum NULL 4 Elem D 1 Ipsum NULL Note: 'listElemOrderPlace' in the table listElement is the final order of the elements (all users average), not to be mixed with the one with the same name in the other table, that's only a specific user's order of the list elements (which is the interesting one in this case).

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  • SQL SERVER – Storing 64-bit Unsigned Integer Value in Database

    - by Pinal Dave
    Here is a very interesting question I received in an email just another day. Some questions just are so good that it makes me wonder how come I have not faced it first hand. Anyway here is the question - “Pinal, I am migrating my database from MySQL to SQL Server and I have faced unique situation. I have been using Unsigned 64-bit integer in MySQL but when I try to migrate that column to SQL Server, I am facing an issue as there is no datatype which I find appropriate for my column. It is now too late to change the datatype and I need immediate solution. One chain of thought was to change the data type of the column from Unsigned 64-bit (BIGINT) to VARCHAR(n) but that will just change the data type for me such that I will face quite a lot of performance related issues in future. In SQL Server we also have the BIGINT data type but that is Signed 64-bit datatype. BIGINT datatype in SQL Server have range of -2^63 (-9,223,372,036,854,775,808) to 2^63-1 (9,223,372,036,854,775,807). However, my digit is much larger than this number. Is there anyway, I can store my big 64-bit Unsigned Integer without loosing much of the performance of by converting it to VARCHAR.” Very interesting question, for the sake of the argument, we can ask user that there should be no need of such a big number or if you are taking about identity column I really doubt that if your table will grow beyond this table. Here the real question which I found interesting was how to store 64-bit unsigned integer value in SQL Server without converting it to String data type. After thinking a bit, I found a fairly simple answer. I can use NUMERIC data type. I can use NUMERIC(20) datatype for 64-bit unsigned integer value, NUMERIC(10) datatype for 32-bit unsigned integer value and NUMERIC(5) datatype for 16-bit unsigned integer value. Numeric datatype supports 38 maximum of 38 precision. Now here is another thing to keep in mind. Using NUMERIC datatype will indeed accept the 64-bit unsigned integer but in future if you try to enter negative value, it will also allow the same. Hence, you will need to put any additional constraint over column to only accept positive integer there. Here is another big concern, SQL Server will store the number as numeric and will treat that as a positive integer for all the practical purpose. You will have to write in your application logic to interpret that as a 64-bit Unsigned Integer. On another side if you are using unsigned integers in your application, there are good chance that you already have logic taking care of the same. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Datatype

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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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  • Commercial web application--scalable database design

    - by Rob Campbell
    I'm designing a set of web apps to track scientific laboratory data. Each laboratory has several members, each of whom will access both their own data and that of their laboratory as a whole. Many typical queries will thus be expected to return records of multiple members (e.g. my mouse, joe's mouse and sally's mouse). I think I have the database fairly well normalized. I'm now wondering how to ensure that users can efficiently access both their own data and their lab's data set when it is mixed among (hopefully) a whole ton of records from other labs. What I've come up with so far is that most tables will end with two fields: user_id and labgroup_id. The WHERE clause of any SELECT statement will include the appropriate reference to one of the id fields ("...WHERE 'labroup_id=n..." or "...WHERE user_id=n..."). My questions are: Is this an approach that will scale to 10^6 or more records? If so, what's the best way to use these fields in a query so that it most efficiently searches the relevant subset of the database? e.g. Should the first step in querying be to create a temporary table containing just the labgroup's data? Or will indexing using some combination of the id, user_id, and labroup_id fields be sufficient at that scale? I thank any responders very much in advance.

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  • Calculate the retrieved rows in database Visual C#

    - by Tanya Lertwichaiworawit
    I am new in Visual C# and would want to know how to calculate the retrieved data from a database. Using the above GUI, when "Calculate" is click, the program will display the number of students in textBox1, and the average GPA of all students in textBox2. Here is my database table "Students": I was able to display the number of students but I'm still confused to how I can calculate the average GPA Here's my code: private void button1_Click(object sender, EventArgs e) { string connection = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Database1.accdb"; OleDbConnection connect = new OleDbConnection(connection); string sql = "SELECT * FROM Students"; connect.Open(); OleDbCommand command = new OleDbCommand(sql, connect); DataSet data = new DataSet(); OleDbDataAdapter adapter = new OleDbDataAdapter(command); adapter.Fill(data, "Students"); textBox1.Text = data.Tables["Students"].Rows.Count.ToString(); double gpa; for (int i = 0; i < data.Tables["Students"].Rows.Count; i++) { gpa = Convert.ToDouble(data.Tables["Students"].Rows[i][2]); } connect.Close(); }

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  • Is there a better loop I could write to reduce database queries?

    - by dmanexe
    Below is some code I've written that is effective, but makes too many database queries. Is there a way I could optimize and reduce the number of queries but have conditional statements still be as effective as below? I pasted the code repeated a few times just for good measure. echo "<h3>Pool Packages</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE && $query->category == "Pool Packages") { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Pool Packages") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { } endforeach; echo "</ul>"; echo "<h3>Water Features</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE && $query->category == "Water Features") { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Water Features") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { } endforeach; echo "</ul>"; echo "<h3>Waterfall Rock Work</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE) { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Waterfall Rock Work") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { } endforeach; echo "</ul>"; echo "<h3>Sheer Descents</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE && $query->category == "Sheer Descents") { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Sheer Descents") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { } endforeach; echo "</ul>"; echo "<h3>Booster Pump</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE && $query->category == "Booster Pump") { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Booster Pump") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { } endforeach; echo "</ul>"; echo "<h3>Pool Concrete Decking</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE && $query->category == "Pool Concrete Decking") { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Pool Concrete Decking") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { } endforeach; echo "</ul>"; echo "<h3>Solar Heating</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE && $query->category == "Solar Heating") { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Solar Heating") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { } endforeach; echo "</ul>"; echo "<h3>Raised Bond Beam</h3>"; echo "<ul>"; foreach ($items as $item): $this->db->where('id', $item['id']); $query = $this->db->get('items')->row(); if ($item['quantity'] > 1 && $item['quantity'] == TRUE && $query->category == "Raised Bond Beam") { $newprice = $item['quantity'] * $query->price; $totals[] = $newprice; } else { $newprice = $query->price; $totals[] = $newprice; } if ($query->category == "Raised Bond Beam") { echo "<li>" . $query->name . " (QTY: " . $item['quantity'] . " x = " . str_ireplace(" ", "", money_format('%(#10n', $newprice)) . ")</li>"; } else { echo "<li>None</li>"; } endforeach; echo "</ul>"; It goes on beyond this to several more categories, but I don't know how to handle looping through this best. Thanks!

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  • SQL SERVER – Automated Type Conversion using Expressor Studio

    - by pinaldave
    Recently I had an interesting situation during my consultation project. Let me share to you how I solved the problem using Expressor Studio. Consider a situation in which you need to read a field, such as customer_identifier, from a text file and pass that field into a database table. In the source file’s metadata structure, customer_identifier is described as a string; however, in the target database table, customer_identifier is described as an integer. Legitimately, all the source values for customer_identifier are valid numbers, such as “109380”. To implement this in an ETL application, you probably would have hard-coded a type conversion function call, such as: output.customer_identifier=stringToInteger(input.customer_identifier) That wasn’t so bad, was it? For this instance, programming this hard-coded type conversion function call was relatively easy. However, hard-coding, whether type conversion code or other business rule code, almost always means that the application containing hard-coded fields, function calls, and values is: a) specific to an instance of use; b) is difficult to adapt to new situations; and c) doesn’t contain many reusable sub-parts. Therefore, in the long run, applications with hard-coded type conversion function calls don’t scale well. In addition, they increase the overall level of effort and degree of difficulty to write and maintain the ETL applications. To get around the trappings of hard-coding type conversion function calls, developers need an access to smarter typing systems. Expressor Studio product offers this feature exactly, by providing developers with a type conversion automation engine based on type abstraction. The theory behind the engine is quite simple. A user specifies abstract data fields in the engine, and then writes applications against the abstractions (whereas in most ETL software, developers develop applications against the physical model). When a Studio-built application is run, Studio’s engine automatically converts the source type to the abstracted data field’s type and converts the abstracted data field’s type to the target type. The engine can do this because it has a couple of built-in rules for type conversions. So, using the example above, a developer could specify customer_identifier as an abstract data field with a type of integer when using Expressor Studio. Upon reading the string value from the text file, Studio’s type conversion engine automatically converts the source field from the type specified in the source’s metadata structure to the abstract field’s type. At the time of writing the data value to the target database, the engine doesn’t have any work to do because the abstract data type and the target data type are just the same. Had they been different, the engine would have automatically provided the conversion. ?Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Database, Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology Tagged: SSIS

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  • Database time data retrieval, time based queries

    - by Raphael Pineda
    I am new to time manipulation or time arithmetic operations and am currently developing a navigation system with Web server based information and currently I have this Database that contains a table peek hours whose columns are id, start_time, end_time , edge_id, day_of_the_week, edge_weight ------------------------------------------------------------------------ | Peek Hours | ------------------------------------------------------------------------ | | | | | | | | id | start_time | end_time | edge_id | day_of_the_week | edge_weight | | | | | | | | ------------------------------------------------------------------------ I am using PHP as a webservice and so based on the current time i want to get all the records that would fit this equation start_time< current_time < end_time

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  • What database field should this be?

    - by alex
    I have a table called "Event". A column has "duration"--which is...how long that event lasts. What database type should this be? Integer? (in seconds)? In the future, I will do statements such as: If now() > event.duration THEN don't display the event.

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  • Database query optimization

    - by hdx
    Ok my Giant friends once again I seek a little space in your shoulders :P Here is the issue, I have a python script that is fixing some database issues but it is taking way too long, the main update statement is this: cursor.execute("UPDATE jiveuser SET username = '%s' WHERE userid = %d" % (newName,userId)) That is getting called about 9500 times with different newName and userid pairs... Any suggestions on how to speed up the process? Maybe somehow a way where I can do all updates with just one query? Any help will be much appreciated! PS: Postgres is the db being used.

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