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• Database design: one huge table or separate tables?

  - by littlegreen

  Currently I am designing a database for use in our company. We are using SQL Server 2008. The database will hold data gathered from several customers. The goal of the database is to acquire aggregate benchmark numbers over several customers. Recently, I have become worried with the fact that one table in particular will be getting very big. Each customer has approximately 20.000.000 rows of data, and there will soon be 30 customers in the database (if not more). A lot of queries will be done on this table. I am already noticing performance issues and users being temporarily locked out. My question, will we be able to handle this table in the future, or is it better to split this table up into smaller tables for each customer?

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• Re-use aliased field in SQL SELECT STATEMENT

  - by Bad Display Name

  Hi, the question is hard to define without giving an example, e.g. I'd like to achieve something like this : SELECT (CASE WHEN ...) AS FieldA, 20 + FieldA AS FieldB FROM Tbl Assuming that by "..." I've replaced a long and complex CASE statement, hence I don't want to repeat it when selecting FieldB and use the aliased FieldA instead. IS THIS EVEN POSSIBLE? What could be a workaround? Note, that this will return multiple rows , hence the DECLARE/SET outside the SELECT statement is no good in my case. PLEASE HELP. P.S. I am using SQL 2008

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• Dynamic SQL queries in code possible?

  - by SeanD

  Instead of hard coding sql queries like Select * from users where user_id =220202 can these be made dynamic like Select * from $users where $user_id = $input. Reason i ask is when changes are needed to table/column names i can just update it in one place and don't have to ask developers to go line by line to find all references to update. It is very time consuming. And I do not like the idea of exposing database stuff in the code. My major concern is load time. Like with dynamic pages, the database has to fetch the page content, same way if queries are dynamic first system has to lookup the references then execute the queries, so does it impact load times? I am using codeignitor PHP. If it it possible then the next question is where to store all the references? In the app, in a file, in the DB, and how?

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• Find gap between start and end dates for multiple data ranges with overlaps

  - by sqlint

  Need to find gap between start and end dates more than 20 days for multiple data ranges with overlaps. One Id has multiple start dates and end dates. Following Id 1 has two gaps less that 20 day. It should be considered as one range from 10/01/2012 to 10/30/2014 without any gap. 1 10/01/2012 02/01/2013 1 01/01/2013 01/31/2013 1 02/10/2013 03/31/2013 1 04/15/2013 10/30/2014 Id 2 has a gap more than 20 days between end date 01/30/2013 and start date 05/01/2013. It has to be captured. 2 01/01/2013 01/30/2013 2 05/01/2013 06/30/2014 2 07/01/2013 02/01/2014 Id 3 should be considered as one range from 01/01/2012 to 06/01/2014 without any gap. The gap between end date 02/28/2013 and start date 07/01/2013 should be ignored because range from 01/01/2012 to 01/01/2014 cavers a gap. 3 01/01/2012 01/01/2014 3 01/01/2013 02/28/2013 3 07/01/2013 06/01/2014 The cursor can do it but it works extremely slow and not acceptable. SQL fiddle http://sqlfiddle.com/#!3/27e3f/2/0

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• SQL: joining multiples tables into one.

  - by Graveen

  I have 4 tables. r1, r2, r3 and r4. The table columns are the following: rId | rName I want to have, in fine, an unique table - let's call it R. Obviously, R will have the following structure: rTableName | rId | rName I'm looking for a solution, and the more natural for me is to: add a single column to all rX insert this column the table name i'm processing generate SQLs and concatenate them all Although I see exactly how to perform 1 and 3 with batching, editing, etc... (I have only to perform it once and for all), I don't see how to do the point 2: self-getting the tablename to insert into SQL. Have you an idea / or a different way to do that could solve my problem? Note: In fact, there are 250+ rX tables. That's why i can't do this manually. Note2: Precisely, this is with MySQL.

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• Conditional PIVOT/transform problem

  - by IanC

  Hi folks I have a table with three columns, which we'll call ID1, ID2, and Value. Sample data: ID ID1 Value 1 1 0 1 2 1 1 3 1 1 3 2 1 4 0 1 4 1 1 5 0 1 5 2 2 1 2 Value is limited to 0, 1, or 2. What I need to do is pivot/transform this data into a column-based count of how many times each possible Value appears, grouped by ID, ID1. The output of the above should be: ID ID1 Val0 Val1 Val2 1 1 1 0 0 1 2 0 2 0 1 3 0 1 1 1 4 1 1 0 1 5 1 0 1 2 1 0 0 1 I'm using SQL Server 2008. How do I do this?

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• Show parts of the result of an SQL statement using PHP

  - by mouthpiec

  I have an SQL query which returns a set of data (around 40-50 tuples). I would like to display the results 5 at a time on an HTML page using PHP. I already managed to have the right SELECT statement, but i am having problems to display the results 5 by 5 using a "more" button. Can you please help? Note that every time i call the query, the data is being randomized, so it is not possible to set limits and call the query again. I have to find the method to store the results somewhere, and then show them 5 by 5.

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• SQL Select between two fields depending on the value of one field

  - by Filip

  Hi. I am using a PostgreSQL database, and in a table representing some measurements I've two columns: measurement, and interpolated. In the first I've the observation (measurement), and b is the interpolated value depending on nearby values. Every record with an original value has also an interpolated value. However, there are a lot of records without "original" observations (NULL), hence the values are interpolated and stored in the second column. So basically there are just two cases in the database: Value Value NULL Value Of course, it is preferable to use the value from the first column if available, hence I need to build a query to select the data from the first column, and if not available (NULL), then the database returns the value from the second column for the record in question. I have no idea how to build the SQL query. Please help. Thanks.

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• Multiple column foreign key contraints

  - by eugene4968

  I want to setup table constraints for the following scenario and I’m not sure how to do it or if it’s even possible in SQL Server 2005. I have three tables A,B,C. C is a child of B. B will have a optional foreign key(may be null) referencing A. For performance reasons I also want table C to have the same foreign key reference to table A. The constraint on table C should be that C must reference its parent (B) and also have the same foreign key reference to A as its parent. Anyone have any thoughts on how to do this?

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• Designing Relational Survey Questionnaires Database

  - by user1213055

  I'm trying to build a simple sql database for following access database. Currently there is no relationship and I just have two tables male and female with 6 sections in each form. How can I design it a better way so end user can connect to the database and analyze using STATA or SPSS ? I'm really confused whether I should create one table with all fields or break down into different tables. The database is specific to this study only so I'm not looking for a generic survey database where user can create surveys and capture them. Any feedback or suggestion is much appreciated.

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• INSERT SQL in Java

  - by Pierre

  Hello. I have a Java application and I want to use SQL database. I have a class for my connection : public class SQLConnection{ private static String url = "jdbc:postgresql://localhost:5432/table"; private static String user = "postgres"; private static String passwd = "toto"; private static Connection connect; public static Connection getInstance(){ if(connect == null){ try { connect = DriverManager.getConnection(url, user, passwd); } catch (SQLException e) { JOptionPane.showMessageDialog(null, e.getMessage(), "Connection Error", JOptionPane.ERROR_MESSAGE); } } return connect; } } And now, in another class I succeeded to print my values but when I attempt to insert a value nothing is happening ... Here's my code : try { Statement state = SQLConnection.getInstance().createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY); Statement state2 = SQLConnection.getInstance().createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE); state2.executeUpdate("INSERT INTO table(field1) VALUES (\"Value\")"); // Here's my problem ResultSet res = state.executeQuery("SELECT * FROM plateau");

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• Excel isn't reading sql exported csv properly

  - by mhopkins321

  I have a batch file that calls sqlcmd to run a command and then export the data as a csv. When viewed in a cell the trasancted date for example shows 35:30.0 but if you click on it the formula bar shows 1/1/1900 2:45:00 PM. I need the full timestamp to show in the cell. Any ideas? The batch file is the following sqlcmd -S server -U username -P password -d database -i "D:\path\sqlScript.sql" -s "," > D:\path\report.csv -I -W -k 1 The script is the following. Now I currently have them cast as varchars, but that's simply because i've tried to change it a bit. Varchar doesn't work either. SET NOCOUNT ON; select top(10)BO.Status, cast(tradeDate AS varchar) AS Trade_Date, CAST(closingTime AS varchar) AS Closing_Time, CAST(openingTime AS varchar) AS openingTime FROM GIANT COMPLICATED JOINS OF ALL SORTS OF TABLES

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• Add Unique Key For Nullable Columns - SQL Server

  - by Ruby

  I'm using sql server 2008 R2 and would like to apply unique key constraint to nullable columns. This code works good, but if I have multiple columns to add this rule to, it would generate as many 'nullbuster' columns. ALTER TABLE tblBranch ADD nullbuster AS (CASE WHEN column1 IS NULL THEN BranchID ELSE NULL END); CREATE UNIQUE INDEX UK_Column1 ON tblBranch(column1,nullbuster); tblBranch is the table name, nullbuster would be the new column name, BranchId is the Primary key column of the target table, and Column1 is the column name of the target column. Is there any way that I could achieve the goal without generating new columns.

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• Remove specific string from multiple database rows in SQL

  - by Scott

  I have a column that contains page titles, which has the website name appended to the end of each. (e.g. Product Name | Company Name Inc.) I would like to remove the " | Company Name Inc." from multiple rows simultaneously. What SQl query commands (or query itself) would allow me to accomplish this? To re-illustrate, I want to convert multiple rows of 1 column from this: Product Name | Company Name Inc. To this: Product Name

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• SQL CREATE TABLE Error

  - by Adam M-W

  Hi, I've been stuck on this one simple(ish) thing for the last 1/2 hour so I thought I might try to get a quick answer here. What exactly is incorrect about my SQL syntax, assuming I'm using mysql 5.1 CREATE TABLE 'users' ( 'id' MEDIUMINT(8) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, 'username' VARCHAR(20) NOT NULL, 'password' VARCHAR(40) NOT NULL, 'salt' VARCHAR(40) DEFAULT NULL, 'email' VARCHAR(80) NOT NULL, 'created_on' INT(11) UNSIGNED NOT NULL, 'last_login' INT(11) UNSIGNED DEFAULT NULL, 'active' TINYINT(1) UNSIGNED DEFAULT NULL, ) ENGINE InnoDB; Also, does anyone have any good tutorials about how to use Zend_Auth for complete noobs? Thanks.

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• SQL query problem

  - by Brisonela

  Hi, I'm new to StackOverflow, and new to SQL Server, I'd like you to help me with some troublesome query. This is my database structure(It's half spanish, hope doesn't matter) Database My problem is that I don't now how to make a query that states which team is local and which is visitor(using table TMatch, knowing that the stadium belongs to only one team) This is as far as I can get Select P.NroMatch, (select * from fnTeam (P.TeamA)) as TeamA,(select * from fnTeam (P.TeamB)) as TeamB, (select * from fnEstadium (P.CodEstadium)) as Estadium, (cast(P.GolesTeamA as varchar)) + '-' + (cast(P.GolesTeamA as varchar)) as Score, P.Fecha from TMatch P Using this functions: If object_id ('fnTeam','fn')is not null drop function fnTeam go create function fnTeam(@CodTeam varchar(5)) returns table return(Select Name from TTeam where CodTeam = @CodTeam) go select * from fnTeam ('Eq001') go ----**** If object_id ('fnEstadium','fn')is not null drop function fnEstadium go create function fnEstadium(@CodEstadium varchar(5)) returns table return(Select Name from TEstadium where CodEstadium = @CodEstadium) go I hope I'd explained myself well, and I thank you help in advance

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• How can an SQL query return data from multiple tables

  - by Fluffeh

  I would like to know how to get data from multiple tables in my database, what types of methods are there to do this, what are joins and unions and how are they different from one another? When should I use each one compared to the others? I am planning to use this in my (for example - PHP) application, but don't want to run multiple queries against the database, what options do I have to get data from multiple tables in a single query? Note: I am writing this as I would like to be able to link to a well written guide on the numerous questions that I constantly come across in the PHP queue, so I can link to this for further detail when I post an answer. The answers cover off the following: Part 1 - Joins and Unions Part 2 - Subqueries Part 3 - Tricks and Efficient Code

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• SQL Server 2005: Rename DB Server Instance Name?

  - by Code Sherpa

  Hi, Can somebody tell me how to rename the DB server instance name and a DB name in SQL Server 2005? Right Now I Have SERVER/OLDNAME -- oldnameDB I want to change the server instance and also change the db name. I have tried: EXEC sp_renamedb 'oldName', 'newName' and that has changed the dbname as it appers in the tree directory. But, when I do "select @@servername" it is the old name. Also, the MDF and LDF files are still the old name. How do change instance and db names as a clean sweep across the server? Thanks.

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• How to use the merge command

  - by Vaccano

  Say I have a table called Employee (has ID, NAME, ADDRESS, and PHONE columns). (Not my real problem, but simplified to make the question easier.) If I call a sproc called UpdateEmployee and I pass in a @Name, @Address, @Phone and @ID. Can merge be used to easily check to see if the ID exists? If it does to update the name, address and phone? and if it does not to insert them? I see examples on the net, but they are huge and hairy. I would like a nice simple example if possible. (We recently upgraded to SQL 2008, so I am new to the merge command.)

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• SQL finding overlapping of times pass midnight (across 2 days)

  - by janechii

  Hi everyone, I know there are lots of these types of questions, but i didn't see one that was similar enough to my criteria. So i'd like to ask for your help please. The fields i have are just start and end which are of time types. I cannot involve any specific dates in this. If the time ranges don't go pass midnight across day, i'd just compare two tuples as such: end1 > start2 AND start1 < end2 (end points touching are not considered overlapped here.) But when I involve time range that pass (or at) midnight, this obviously doesn't work. For example, given: start | end --------+-------- 06:00PM | 01:00AM 03:00PM | 09:00PM Without involving dates, how can i achieve this, please. My assumption is, if end is less than start, then we're involving 2 days. I'm trying to do this in plain standard SQL, so just a simple and concise logic in the WHERE clause. Thank you everyone!

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• Similar SQL queries returning different results...

  - by Pablo

  Here are the SQL Queries: $sql1 = "SELECT count(thread) AS total FROM comments WHERE thread=1 AND parent_id=0 "; $sql2 = "SELECT count(thread) AS total FROM comments, users WHERE thread=1 AND parent_id=0 AND users.user_id=comments.user_id "; $sql3 = "SELECT comments.*, users.username AS username FROM comments, users WHERE thread=1 AND parent_id=0 AND users.user_id=comments.user_id ORDER BY date LIMIT 10, 5 "; My question is why would $sql1 and $sql2 would return two different results? $sql1 returns 61 rows $sql2 returns 56 rows The 5th line in $sql2 is just for testing, is not required, is just a variation of $sql1 which gets the total rows for a pagination.

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• big size of database-log SQL-Server 2008

  - by t.kehl

  I have a database which is running under Microsoft SQL Server 2008. Now, I have seen, that the log of the database (ldf-file) is growing to big size. The database-file (mdf) has a size of 630MB and the log-file has a size of 12GB. I ask me now, what the reason for this can be. Is there a tool which let me seeing into the log where I can see, what is the reason for this big size? What can I do to prevent that the log is growing to this big size?

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• SQL query not working

  - by Ziv

  hi, I'm trying to create a query in an access database for a C# dataset using the query editor but the created method says there is a problem and isn't created correctly. SELECT Discs.* FROM Discs WHERE (Title=@Title OR @Title IS NULL) AND (Type=@Type OR @Type IS NULL) AND (ContainerID=@ContainerID OR @ContainerID IS NULL) AND NOT (@Title IS NULL AND @Type IS NULL AND @ContainerID IS NULL) the error is: Generated SELECT statement. Error in WHERE clause near '@'. Unable to parse query text. the generated select method doesn't have any parameters and is unusable. I've tried the exact same SQL statement in the access query and it worked flawlessly, what am I supposed to be doing differently when transferring it to C#?

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• Sql-server Database query help

  - by menacheb

  Hi, I have a problem that I didn't manage to solve for a very long time, and I quite desperate. I have a Database (SQL Server) with table named 'ProcessData' and columns named 'Process_Name' (Data Type: nvarchar(50)), 'Start_At' (DataType: DateTime) and 'End_At' (Data Type: DateTime). I need to know for each 'Time-Interval' (let's say 1 minute) how many processes (Process_Name = PN) was open (after or equal to the 'Start_at' column and before or equal to the 'End_At' column) during this time (It can be a few rows with the same data). Does anyone know how to make this query without a 'for' loop? (It ITSELF will promote the time), (The answer will be a table with two columns (1. The time the check took place. 2. the number of open processes at this time.) and a row for each 'Time-Interval' (1 minute in this example ) Many thanks,

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• How do I switch the table that is queried with linq-to-sql

  - by Ian Ringrose

  We have two tables with the same set of columns; depending on the “type” of object the value is stored in one of the two tables. I wish to use common code to access these two tables. If I was using “raw sql” I could just use String.Format() to change the table name. (Likewise for updates etc) The two separate tables are needed as the data access patterns are very different for the common queries on the two tables and therefore different indexes are needed. “Views” and “instead of triggers” etc to make the tables look like a single table are not liked here. A lot of our customers use low end version of SqlServer so we cannot use partition tables.

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