[MySQL]使用EXISTS代替IN
标签：log not where from style class weight 使用 mys
[MySQL]使用EXISTS代替IN
-> EXISTS
SELECT * FROM CouponItem AS A WHERE A.CouponId IN(SELECT B.Id FROM Coupon AS B WHERE B.Id<30);
SELECT * FROM CouponItem AS A WHERE EXISTS(SELECT B.Id FROM Coupon AS B WHERE B.Id<30 AND A.CouponId=B.Id);
#NOT IN -> NOT EXISTS
SELECT * FROM CouponItem AS A WHERE A.CouponId NOT IN(SELECT B.Id FROM Coupon AS B WHERE B.Id<30);
SELECT * FROM CouponItem AS A WHERE NOT EXISTS(SELECT B.Id FROM Coupon AS B WHERE B.Id<30 AND A.CouponId=B.Id);