大约有 40,000 项符合查询结果（耗时：0.0235秒） [XML]
MySQL - length() vs char_length()
...ore accurately UTF-16LE) is what Windows misleadingly calls “Unicode”. MySQL doesn't support UTF-16; instead the usual approach for putting Unicode strings in it is to use UTF-8.
– bobince
Nov 14 '09 at 14:20
...
How to do a regular expression replace in MySQL?
...
With MySQL 8.0+ you could use natively REGEXP_REPLACE function.
12.5.2 Regular Expressions:
REGEXP_REPLACE(expr, pat, repl[, pos[, occurrence[, match_type]]])
Replaces occurrences in the string expr that match the regular express...
What columns generally make good indexes?
...er to use index */
Since "buyer_id" is referenced in the SELECT portion, MySQL will not use it to limit the chosen rows. Hence, there is no great need to index it. The below is another example little different from the above one:
SELECT
buyers.buyer_id, /* no need to index */
country.name /*...
MySQL: Sort GROUP_CONCAT values
...
Sure, see http://dev.mysql.com/doc/refman/...tions.html#function_group-concat:
SELECT student_name,
GROUP_CONCAT(DISTINCT test_score ORDER BY test_score DESC SEPARATOR ' ')
FROM student
GROUP BY student_name;
...
ATL COM开发入门（一）（JS调用ActiveX/COM组件） - C/C++ - 清泛网 - 专注C/C++及内核技术
...它进行COM开发。本文通过一个基础入门的例子，简要介绍如何定义、实现C...ATL（Active Template Library）动态模板库，是一个类库，可以使用它进行COM开发。本文通过一个基础入门的例子，简要介绍如何定义、实现COM接口，前台如何...
How to change the name of a Django app?
...E <oldAppName>_modelName RENAME TO <newAppName>_modelName. For mysql too I think it is the same (as mentioned by @null_radix)
(For Django >= 1.7) Update the django_migrations table to avoid having your previous migrations re-run: UPDATE django_migrations SET app='<NewAppName>' W...
Rename a table in MySQL
Renaming a table is not working in MySQL
16 Answers
16
...
Commands out of sync; you can't run this command now
I am trying to execute my PHP code, which calls two MySQL queries via mysqli, and get the error "Commands out of sync; you can't run this command now".
...
Insert into … values ( SELECT … FROM … )
... struggle to remember the correct syntax for the SQL engine of the day ( MySQL , Oracle , SQL Server , Informix , and DB2 ).
...
Checking for an empty field with MySQL
...)" and there's one record with null hotline but it doesn't match.I'm using MySQL 5.6
– Scott Chu
Apr 15 '16 at 10:16
...