Question

这样的sql语句怎么写:表名A ,字段名A_1,A_1字段里面只有数值1或者2，现在想把是1的显示为B,2显示为S

Answer 1

使用如下语句即可：
select case when a_1 = '1' then 'B' when a_1 = '2' then 'S' else a_1 end as a_1 from a;

Answer 2

select decode(A_a,1,B,S) from A