大约有 40,000 项符合查询结果（耗时：0.0216秒） [XML]
How to check if field is null or empty in MySQL?
...
Either use
SELECT IF(field1 IS NULL or field1 = '', 'empty', field1) as field1
from tablename
or
SELECT case when field1 IS NULL or field1 = ''
then 'empty'
else field1
end as field1
from tablename
...
How to drop unique in MySQL?
...
DROP INDEX column_name ON table_name
Select the database and query form the sql tab.This removes the index of the particular column. It worked for me in PHP MyADMIN
share
|
...
Run php script as daemon process
... service:
[Unit]
Description=My PHP Daemon Service
#May your script needs MySQL or other services to run, eg. MySQL Memcached
Requires=mysqld.service memcached.service
After=mysqld.service memcached.service
[Service]
User=root
Type=simple
TimeoutSec=0
PIDFile=/var/run/myphpdaemon.pid
ExecStart=/u...
mysql_config not found when installing mysqldb python interface
...one Building dependency tree Reading state information...Done Note, selecting libmysqlclient15-dev instead of libmysqlclient-dev Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required...
How do I list all the columns in a table?
...
For Oracle (PL/SQL)
SELECT column_name
FROM user_tab_cols
WHERE table_name = 'myTableName'
For MySQL
SHOW COLUMNS FROM table_name
share
|
i...
Which MySQL datatype to use for an IP address? [duplicate]
...nvert them:
INSERT INTO `table` (`ipv4`) VALUES (INET_ATON("127.0.0.1"));
SELECT INET_NTOA(`ipv4`) FROM `table`;
For IPv6 addresses you could use a BINARY instead:
`ipv6` BINARY(16)
And use PHP’s inet_pton and inet_ntop for conversion:
'INSERT INTO `table` (`ipv6`) VALUES ("'.mysqli_real_es...
What is the leading LINQ for JavaScript library? [closed]
... different names (in fact, they have more traditional names than in Linq). Select becomes map, Where becomes filter, First and FirstOrDefault become [0].
Almost no library I know of (including I think the ones you linked to) bother to make the implementation lazy as in .NET Linq, they just evaluate...
How to delete a certain row from mysql table with same column values?
...ike this:
DELETE FROM your_table WHERE id_users=1 AND id_product=2
LIMIT (SELECT COUNT(*)-1 FROM your_table WHERE id_users=1 AND id_product=2)
share
|
improve this answer
|
...
Select where count of one field is greater than one
...clause, for aggregate result comparison.
Taking the query at face value:
SELECT *
FROM db.table
HAVING COUNT(someField) > 1
Ideally, there should be a GROUP BY defined for proper valuation in the HAVING clause, but MySQL does allow hidden columns from the GROUP BY...
Is this in preparati...
MySQL InnoDB not releasing disk space after deleting data rows from table
... recreate your table and regain diskspace
Create TBL_B like TBL_A . Insert select data you want to keep from TBL_A into TBL_B. Drop TBL_A, and rename TBL_B to TBL_A. This way is very effective if TBL_A and data that needed to delete is big (delete command in MySQL innodb is very bad performance)
...