PostgreSQL空值的判断
空值判断
sql
-- 查询为空的 is null,sql简写isnull
select * from employees where manager_id isnull;
sql
select * from employees where manager_id is null;
非空判断
sql
-- 查询不为空的 is not null;sql简写notnull
select * from employees where manager_id is not null;
select * from employees where manager_id notnull;