经典的mysql讲解和语句

select count(*) as col_0_0_ from tb_operationexaminesubjects operatione0_ where 1=1 and operatione0_.delState=1 and (operatione0_.subject like '%sa%') 
and operatione0_.lincenseType=1 order by operatione0_.createDate descselect count(*) as col_0_0_ from tb_operationexaminesubjects operatione0_ where 1=1 
and operatione0_.delState=1 and (operatione0_.subject like '%sa%') and operatione0_.lincenseType=1 order by operatione0_.createDate desc   条件查询



select operatione0_.id as id29_, operatione0_.lincenseType as lincense2_29_, operatione0_.operationType as operatio3_29_, operatione0_.subject as
 subject29_, operatione0_.examineType as examineT5_29_, operatione0_.Examecontype as Examecon6_29_, operatione0_.Tabletype as Tabletype29_, 
operatione0_.Tabletypesub as Tabletyp8_29_, operatione0_.score as score29_, operatione0_.areaId as areaId29_, operatione0_.creatorId as creatorId29_, 
operatione0_.createDate as createDate29_, operatione0_.lastUpdatorId as lastUpd13_29_, operatione0_.lastUpdateDate as lastUpd14_29_, operatione0_.oid as 
oid29_, operatione0_.delState as delState29_, operatione0_.orgCode as orgCode29_ from tb_operationexaminesubjects operatione0_ where 1=1 and 
operatione0_.delState=1 and (operatione0_.subject like '%12%') and operatione0_.lincenseType=1 order by operatione0_.createDate desc limit 3  按照条件返回表中的某几个数据



select operationc0_.id as 编号, operationc0_.reanswer as 名称, operationc0_.Subject as 外键 from tb_operationconsult operationc0_ where
 operationc0_.Subject=43357   查询，并替换列名


链表sql语句：select pe.score,tr.train_subject,tt.training_type_name from person_training  as   pe   inner join training_info 
as  tr on pe.train_id = tr.train_id inner join training_type_info as tt on tr.train_type_id = tt.training_type_id   where pe.person_id=73



统计级联关系：SELECT o.OrgName,o.OrgCode,(SELECT COUNT(*) FROM tb_organizetion org  INNER JOIN tb_userinfo u 
ON org.OID = u.orgId WHERE org.OrgCode LIKE CONCAT(o.OrgCode,'%') AND u.IsActive=1) c,
(SELECT SUM(CASE u.sex WHEN '男' THEN 1 ELSE 0 END) FROM tb_organizetion org INNER JOIN tb_userinfo u 
ON org.OID = u.orgId WHERE org.OrgCode LIKE CONCAT(o.OrgCode,'%') AND u.IsActive=1) male,
(SELECT SUM(CASE u.sex WHEN '女' THEN 1 ELSE 0 END) FROM tb_organizetion org INNER JOIN tb_userinfo u 
ON org.OID = u.orgId WHERE org.OrgCode LIKE CONCAT(o.OrgCode,'%') AND u.IsActive=1) female