sql92语句与sql99语法的区别
场景:测试sql92语句与sql99语法的区别
–创建测试表
CREATE table ypg_08161 as
select ‘1’ as id ,‘one’ as c_name
union all
select ‘2’ as id ,‘two’ as c_name
CREATE table ypg_08162 as
select ‘1’ as id ,‘male’ as c_sex
union all
select ‘3’ as id ,‘female’ as c_sex
第一类:inner join
–sql92语法
select a.id, a.c_name, b.c_sex from ypg_08161 a, ypg_08162 b where a.id=b.id;
id c_name c_sex
1 one male
–sql99语法
select a.id, a.c_name, b.c_sex from ypg_08161 a join ypg_08162 b on a.id=b.id;
id c_name c_sex
1 one male
第二类:left join
–sql92语法
select a.id, a.c_name, b.c_sex from ypg_08161 a, ypg_08162 b where a.id=b.id(+);
id c_name c_sex
1 one male
2 two null
–sql99语法
select a.id, a.c_name, b.c_sex from ypg_08161 a left join ypg_08162 b on a.id=b.id;
id c_name c_sex
1 one male
2 two null