經常使用的sql語句

1：查詢euc_job_dict 表的id，name,重名name的記錄條數，按name分組，且重名數>50條的數據，按數量降序排列

SELECT id,NAME,COUNT(NAME) AS co FROM euc_job_dict GROUP BY NAME HAVING co>50  ORDER BY co DESC;

2:連表查詢：
SELECT * FROM erp_dept AS er LEFT JOIN erp_hr AS eh ON er.bh=eh.bh WHERE eh.deleted IS NULL;

3：模糊匹配 like
select * from erp_dept wher name like "%集團%"

4：關鍵詞：IN 查找在某範圍內的全部記錄
select * from tableA where classid in (select classid from tableb where projid="xxx");

5:刪除數據庫中表的某些相同的某些記錄

delete from tablename where only_Id not in(select min(only_id) from tablename group by sameName)
或者
delete from tablename where only_Id in (select only_id from tableaa group by only_id where count(only_id)>1)