Oracle in 查询数据
问题描述:
查询所有的数据,查询结果:146360
select count(1) from bank_cde;
in查询的获取部分数据,查询结果 :73080
select count(1) from bank_cde t where t.belongcode2 in('ABC','BCOM','BOC','CCB','CEB','CGB','CIB','CITIC','CMBC','ICBC','PAB','POST','SPDB');
not in查询数据,结果为0
select count(1) from bank_cde t where t.belongcode2 not in('ABC','BCOM','BOC','CCB','CEB','CGB','CIB','CITIC','CMBC','ICBC','PAB','POST','SPDB');
原因:
本以为in 和not in 为查询两种结果互补,还有一种情况 为 null
select count(1) from bank_cde t where t.belongcode2 is null;