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What resources exist for Database performance-tuning? [closed]
...er to a not-the-same-inquiry is probably a good start.
Hidden Features of MySQL
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mysql实现split分割字符串（length, SUBSTRING_INDEX, substring） - 爬虫/...
由于MySql没有直接的split函数，只提供了length, SUBSTRING_INDEX, substring三个函数，这里介绍如何用这三个函数实现split功能。
# SUBSTRING_INDEX(str, delim, count)：返回字符串 str 中在第 count 个出现的分隔符 delim 之前的子串。如果 count 是...
Mysql substr和Oracle substr区别 - 爬虫/数据库 - 清泛IT社区，为创新赋能！
Oracle substr(字符串，开始索引、从0起，长度)
Mysql substr或substring(字符串，开始索引、从1起，长度)
How can I append a string to an existing field in MySQL?
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You need to use the CONCAT() function in MySQL for string concatenation:
UPDATE categories SET code = CONCAT(code, '_standard') WHERE id = 1;
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PostgreSQL Autoincrement
I'm switching from MySQL to PostgreSQL and was wondering how I can do autoincrement values. I saw in the PostgreSQL docs a datatype "serial", but I get syntax errors when using it (in v8.0).
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What is the difference between 127.0.0.1 and localhost
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@DonViegues That's MySQL specific and IMO bad design. It will see localhost and tries to use unix-socket instead of connecting using IP but for 127.0.0.1 it just uses IP.
– Arman Ordookhani
Jul 18 '19 at 8...
Mysql error 1452 - Cannot add or update a child row: a foreign key constraint fails
...s another, but it is failing for some reason. With my limited knowledge of MySQL, the only thing that could possibly be suspect is that there is a foreign key on a different table referencing the one I am trying to reference.
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MySQL: How to copy rows, but change a few fields?
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MySQL supports the TEMPORARY keyword to create temporary tables. Usage of CREATE TEMPORARY TABLE will automagically drop the table when the session (a serie of SQL queries) is finished. Dropping the table wouldn't be necessar...
What would be a good docker webdev workflow?
... persistance indepent of your CMS container, you can use one container for MySQL and one container for your CMS. In such case, you can have your MySQL container still running and your can redeploy your CMS as often as you want independently.
For development - the another option is to map mysql data ...
MySQL stored procedure vs function, which would I use when?
I'm looking at MySQL stored procedures and function. What is the real difference?
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