SQL 如何将 两个table 的 字段怎么 合并到一张表

如图，如何将表A和表B合并成表C。记得sql有一个关键字可以实现，可怎么就是想不起来了。

select cast(wr_jc_yearMonth.yearMonth as CHAR(7))+'-'+cast(wr_billCycleSet.billCycle as CHAR(2)) from wr_billCycleSet join wr_jc_yearMonth on 1=1

select cast(wr_jc_yearMonth.yearMonth as CHAR(7))+'-'+cast(wr_billCycleSet.billCycle as CHAR(2)) from wr_billCycleSet join wr_jc_yearMonth on 1=1