merge

merge into copy_emp ce using emp e
on (ce.empno = e.empno)
when matched then
     update set
     ename = e.ename
when not matched then
     insert (empno, ename)
     values(e.empno, e.ename)

注: merge 也属于 dml 操作, 所以操作之后需要进行 commit;

escape 转义字符

SELECT * FROM copy_emp
where ename like ‘XAA\_%‘ ESCAPE ‘\‘

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