Example tutorial on processing special sql statements in mysql
The following editor will bring you a summary of the special processing statements of mysql's sql statements (must read). The editor thinks it’s pretty good, so I’ll share it with you now and give it as a reference. Let’s follow the editor and take a look.
1. Update the entire table. If the value of a column in a row of data is empty, then let it and another The values of a column of fields are equal
UPDATE ot_tgbz set update_day=if(update_day is null,date,update_day);
2,Update the entire table, if a field is greater than 2, then update them all to 2;
UPDATE ot_user set xingyun_num=if(xingyun_num > 2,2,xingyun_num);
3, Replace all URLs containing http://www.jb51.net/ in the thumb field in the shop_goods table with empty ones.
update shop_goods set thumb= replace (thumb,'http://www.jb51.net/','') where thumb like '%http://www.jb51.net/%';
4、sql statement multi-field wherequery
$map= " CAST(
`UE_account` AS CHAR CHARACTER
SET utf8
) LIKE '%$data%'
OR CAST(
`UE_accName` AS CHAR CHARACTER
SET utf8
) LIKE '%$data%'
OR CAST(
`UE_truename` AS CHAR CHARACTER
SET utf8
) LIKE '%$data%'
OR CAST(
`UE_phone` AS CHAR CHARACTER
SET utf8
) LIKE '%$data%'";[Related recommendations]
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