inner join / left join /right join 处理逻辑

示例表

tr_login_name 

fund.fm_risk_assessment 

查询结果

如下实现语句，查询结果都一致，但表位置有区别

表的位置决定 inner join / left join /right join 三种连接查询结果

1、inner join 表位置交换结果一致

2、leif join 与 right join 表位置决定目标表，左联以第一个表为目标表，右连以第二个表为目标表（目标表：即查询结果为 另外表以目标表数据为基础做匹配，显示匹配到的目标表数据，未匹配到则不显示）

select * from member.tr_login_name b;select a.*,rowid from fund.fm_risk_assessment a;select b.login_name,b.* from member.tr_login_name  b inner join  fund.fm_risk_assessment  a on b.member_id = a.member_idwhere b.login_name_type = 2;select b.login_name,b.* from fund.fm_risk_assessment  ainner join   member.tr_login_name  b on b.member_id = a.member_id--where b.login_name_type = 2;select b.login_name,b.* from fund.fm_risk_assessment  aleft  join member.tr_login_name b on a.member_id = b.member_id --where b.login_name_type = 2;select b.login_name,b.* from member.tr_login_name bright join  fund.fm_risk_assessment  aon a.member_id = b.member_id --where b.login_name_type = 2;select b.login_name,b.* from  member.tr_login_name bright  join fund.fm_risk_assessment  a on a.member_id = b.member_id --where b.login_name_type = 2;