作者:贾志军 | 来源:互联网 | 2017-07-07 16:28
MYSQL语句搜索多个表查询不过这种方法对数据库很累为了方便可以使用几千条数据会很卡。SELECT*FROMtable1n1LEFTJOINtable2n2ONn1.typesId=n2.clas
MYSQL语句 搜索多个表查询 不过这种方法对数据库很累 为了方便可以使用 几千条数据会很卡。
SELECT *
FROM table1 n1
LEFT JOIN table2 n2 ON n1.typesId = n2.classid
LEFT JOIN table3 n3 ON n1.members_id = n3.id
LEFT JOIN table4 n4 ON n1.xh_big_id = n4.id
LEFT JOIN table5 n5 ON n1.xh_small_id = n5.small_id
WHERE name LIKE '%关键字%'
ORDER BY n1.id ASC
搜索多条数据 不包含 关键字 或不能为空的 语句
SELECT *
FROM table1 n1
LEFT JOIN table2 n2 ON n1.typesId = n2.classid
WHERE name NOT LIKE '%关键字%' OR name IS NULL
ORDER BY n1.id ASC
搜索重复的字段语句 超过1条的 记录下来
SELECT count(*) AS count, title ,name
FROM table1 n1
LEFT JOIN table2 n2 ON n1.typesId = n2.classid
LEFT JOIN table3 n3 ON n1.members_id = n3.id
LEFT JOIN table4 n4 ON n1.xh_big_id = n4.id
LEFT JOIN table5 n5 ON n1.xh_small_id = n5.small_id
GROUP BY name
HAVING count >= 1
如果想查询两个字段或以上修改以下
GROUP BY title,name
查询重复语句不等于空的
SELECT userName,count(*)
FROM members
WHERE userName <> &#39;NULL&#39;
GROUP BY userName
HAVING count(*) >= 1