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MySQL select where column is not empty
In MySQL, can I select columns only where something exists?
13 Answers
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'0000-00-00 00:00:00' can not be represented as java.sql.Timestamp error
...can use this JDBC URL directly in your data source configuration:
jdbc:mysql://yourserver:3306/yourdatabase?zeroDateTimeBehavior=convertToNull
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For loop example in MySQL
In MySQL, I have this stored procedure with a For loop in it:
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Change limit for “Mysql Row size too large”
... You may want to take a look at this article which explains a lot
about MySQL row sizes. It's important to note that even if you use
TEXT or BLOB fields, your row size could still be over 8K (limit for
InnoDB) because it stores the first 768 bytes for each field inline in
the page.
The...
内存优化总结:ptmalloc、tcmalloc和jemalloc - 操作系统(内核) - 清泛网 - ...
...，tcmalloc性能上也有明显的优势，并且相对平稳。
github mysql优化
github使用tcmalloc后，mysql性能提升30%
Jemalloc
jemalloc是facebook推出的， 最早的时候是freebsd的libc malloc实现。 目前在firefox、facebook服务器各种组件中大量使用。
jemall...
How can I modify the size of column in a MySQL table?
... MODIFY command can do this more concisely.
Re the MEDIUMTEXT thing: a MySQL row can be only 65535 bytes (not counting BLOB/TEXT columns). If you try to change a column to be too large, making the total size of the row 65536 or greater, you may get an error. If you try to declare a column of V...
How should I store GUID in MySQL tables?
...a char 16 binary? not char? not binary? I dont see that type in any of the mysql gui tools, nor any documentation in mysql site. @BillyONeal
– nawfal
Jun 24 '12 at 19:41
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MySQL Insert Where query
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MySQL INSERT Syntax does not support the WHERE clause so your query as it stands will fail. Assuming your id column is unique or primary key:
If you're trying to insert a new row with ID 1 you should be using:
INSERT INTO U...
MYSQL OR vs IN performance
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Performance reason (quoting MariaDB(a MySQL new free branch) docs): Returns 1 if expr is equal to any of the values in the IN list, else returns 0. If all values are constants, they are evaluated according to the type of expr and sorted. The search for the item t...
How can I get enum possible values in a MySQL database?
...wns with enum possible values from a DB automatically. Is this possible in MySQL?
24 Answers
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