sql 取代游标的写法示例

Update Tb_Garden1 G Set Steward = (
Select Id From Zyq.Tb_User U Where Replace(U.Name, '区') = G.Name And Rownum =1)
where exists (select 1 from zyq.tb_user u where Replace(U.Name, '区') = G.Name And rownum = 1)