Sql
Structured Query Language (SQL) is a language for querying databases. Questions should include code examples, table structure, sample data, and a tag for the DBMS implementation (e.g. MySQL, PostgreSQL, Oracle, MS SQL Server, IBM DB2, etc.) being used. If your question relates solely to a specific DBMS (uses specific extensions/features), use that DBMS's tag instead. Answers to questions tagged with SQL should use ISO/IEC standard SQL.
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When to use single quotes, double quotes, and backticks in MySQL
I am trying to learn the best way to write queries. I also understand the importance of being consistent. Unti
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How do I see what character set a MySQL database / table / column is?
What is the (default) charset for: MySQL database MySQL table MySQL column
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MySQL Query GROUP BY day / month / year
Is it possible to make a simple query to count how many records I have in a determined period of time like a y
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How can I temporarily disable a foreign key constraint in MySQL?
Is it possible to temporarily disable constraints in MySQL? I have two Django models, each with a foreign key
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'IF' in 'SELECT' statement - choose output value based on column values
SELECT id, amount FROM report I need amount to be amount if report.type='P' and -amount if report.
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How can I do a FULL OUTER JOIN in MySQL?
I want to do a full outer join in MySQL. Is this possible? Is a full outer join supported by MySQL?
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SQL query to prepend prefix to existing value in a field
I have searched and searched for an answer to this, and I think this must be child's play for anyone who
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Entity Framework. Delete all rows in table
How can I quickly remove all rows in the table using Entity Framework? I am currently using: var rows = from o
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Validation failed for one or more entities while saving changes to SQL Server Database using Entity Framework
I want to save my Edit to Database and I am using Entity FrameWork Code-First in ASP.NET MVC 3 / C# but I am g
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Postgres error: null value in column "id" - during insert operation
I use postgresql and yii2 framework. Well I got a very interesting error message: SQLSTATE[23502]: Not null v
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Matching all values in IN clause
Is there a way to ensure all values in an IN clause are matched? Example: I can use IN as: IN (5,6,7,8). I
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#1273 – Unknown collation: ‘utf8mb4_unicode_520_ci’
I have a WordPress website on my local WAMP server. But when I upload its database to live server, I get error
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DateTime2 vs DateTime in SQL Server
Which one: datetime datetime2 is the recommended way to store date and time in SQL Server 2008+? I'm a
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How can I get column names from a table in SQL Server?
I want to query the name of all columns of a table. I found how to do this in: Oracle MySQL PostgreSQL But I a
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How can I list all foreign keys referencing a given table in SQL Server?
I need to remove a highly referenced table in a SQL Server database. How can I get a list of all the foreign
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How to Join to first row
I'll use a concrete, but hypothetical, example. Each Order normally has only one line item: Orders: Or
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Should I use != or <> for not equal in T-SQL?
I have seen SQL that uses both != and <> for not equal. What is the preferred syntax and why? I like !=
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How can I SELECT rows with MAX(Column value), PARTITION by another column in MYSQL?
My table is: id home datetime player resource 1 10 04/03/2009 john 399 2 11 04/03/2009 juliet 244 5 12 04/03/
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Exclude a column using SELECT * [except columnA] FROM tableA?
We all know that to select all columns from a table, we can use SELECT * FROM tableA Is there a way to excl
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Function vs. Stored Procedure in SQL Server
I've been learning Functions and Stored Procedure for quite a while but I don't know why and when I