oracle or并集 和and交集
or并集 and交集; 然后串联 合并
但是 AND比OR的优先级高
1.SELECT * FROM cxzjg_across_dept_apply WHERE ( status =’2’OR STATuS= ‘3’) AND user_dept_id=’1005’ ;
2.SELECT * FROM cxzjg_across_dept_apply WHERE user_dept_id=’1005’ AND status =’2’OR STATuS= ‘3’ ;