大约有 40,000 项符合查询结果（耗时：0.0210秒） [XML]
JOIN queries vs multiple queries
...han several queries? (You run your main query, and then you run many other SELECTs based on the results from your main query)
...
Create boolean column in MySQL with false as default value?
... into mytable () values ();
Query OK, 1 row affected (0.00 sec)
mysql> select * from mytable;
+--------+
| mybool |
+--------+
| 0 |
+--------+
1 row in set (0.00 sec)
FYI: My test was done on the following version of MySQL:
mysql> select version();
+----------------+
| version() ...
How to fix “Incorrect string value” errors?
...ify that the tables where the data is stored have the utf8 character set:
SELECT
`tables`.`TABLE_NAME`,
`collations`.`character_set_name`
FROM
`information_schema`.`TABLES` AS `tables`,
`information_schema`.`COLLATION_CHARACTER_SET_APPLICABILITY` AS `collations`
WHERE
`tables`.`table_sche...
file_put_contents - failed to open stream: Permission denied
...ld now, but there's no need to manually write queries to a file like this. MySQL has logging support built in, you just need to enable it within your dev environment.
Take a look at the documentation for the 'general query log':
http://dev.mysql.com/doc/refman/5.1/en/query-log.html
...
MySQL convert date string to Unix timestamp
...
Here's an example of how to convert DATETIME to UNIX timestamp:
SELECT UNIX_TIMESTAMP(STR_TO_DATE('Apr 15 2012 12:00AM', '%M %d %Y %h:%i%p'))
Here's an example of how to change date format:
SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(STR_TO_DATE('Apr 15 2012 12:00AM', '%M %d %Y %h:%i%p')),'%m-%d-...
MySQL - ORDER BY values within IN()
...
SELECT id, name
FROM mytable
WHERE name IN ('B', 'A', 'D', 'E', 'C')
ORDER BY FIELD(name, 'B', 'A', 'D', 'E', 'C')
The FIELD function returns the position of the first string in the remaining list of strings.
However, it i...
How to change the default charset of a MySQL table?
... in a database, you can use this query and execute the resulted queries : SELECT concat('alter table ', table_name, ' CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;') FROM information_schema.tables WHERE table_schema='<your_database_name>' and table_collation != 'utf8_general_ci' GR...
How to find the php.ini file used by the command line?
I need to enable pdo_mysql in my EasyPhp environment, so I went to php.ini file and uncommented the following line:
14 Answ...
Commands out of sync; you can't run this command now
... where is it easily displayed. Thanks. I just seperate my queries with $select_stmt->close(); to split them (not simultaneous but procedural
– n34_panda
Jun 7 '14 at 11:13
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How to convert timestamp to datetime in MySQL?
...
SELECT from_unixtime( TIMESTAMP( "2011-12-01", "22:01:23.048" ) ) doesn't work. why? using v5.6
– Janus Troelsen
Feb 4 '14 at 18:44
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