定义行级触发器使用()
A: FOR EACH STATEMENT
B: FOR EACH TABLE
C: FOR EACH ROW
D: FOR EACH COL
A: FOR EACH STATEMENT
B: FOR EACH TABLE
C: FOR EACH ROW
D: FOR EACH COL
举一反三
- 语句级触发器（FOR EACH STATEMENT ）的触发器触发事件发生后，触发器只执行一次。
- Mysql 中创建触发器的语句格式正确的是（ ）。 A: create trigger… for each row … B: create trigger… on…for each row … C: create trigger… on…for each row D: create trigger… on tableName
- 【单选题】创建一个触发器的语句基本结构是 A. delimiter $$ create trigger 触发器名 触发时刻 触发事件 on 表名 for each row begin 触发器动作 end$$ delimiter ; B. delimiter $$ create function 触发器名 触发时刻 触发事件 on 表名 for each row begin 触发器动作 end$$ delimiter ; C. delimiter $$ create view 触发器名 触发时刻 触发事件 on 表名 for each row begin 触发器动作 end$$ delimiter ; D. delimiter $$ create procedure 触发器名 触发时刻 触发事件 on 表名 for each row begin 触发器动作 end$$ delimiter ;
- 下列新增一个DELETE触发器语句正确的是（）。 A: CREATE TRIGGER deleteorder BEFORE DELETE ON orders FOR EACH ROW B: CREATE TRIGGER deleteorder BEFORE INSERT ON orders FOR EACH ROW C: CREATE TRIGGER deleteorder BEFORE DROP ON orders FOR EACH ROW D: CREATE TRIGGER deleteorder BEFORE UPDATE ON orders FOR EACH ROW
- If a is a 3×3 matrix, the function of the function mean(a) is ( ). A: to calculate the average of each row of a B: to calculate the average of each column of a C: to increase a row of the average for a D: to increase a column of the average for a