mysql数据库的函数和存储过程

--调用存储过程
DELIMITER ;
CALL insert_dept(100,10); 

--创建往dept表中插入数据的存储过程
DELIMITER $$
CREATE PROCEDURE insert_dept(IN START INT(10),IN max_num INT(10))  
BEGIN  
DECLARE i INT DEFAULT 0;   
 SET autocommit = 0;    
 REPEAT  
 SET i = i + 1;  
 INSERT INTO dept (deptno ,dname,loc ) VALUES ((START+i) ,rand_string(10),rand_string(8));  
 UNTIL i = max_num  
 END REPEAT;  
 COMMIT;  
 END $$ 

---创建往emp表中插入数据的存储过程
DELIMITER $$
CREATE PROCEDURE insert_emp(IN START INT(10),IN max_num INT(10))  
BEGIN  
DECLARE i INT DEFAULT 0;   
#set autocommit =0 把autocommit设置成0  
 SET autocommit = 0;    
 REPEAT  
 SET i = i + 1;  
 INSERT INTO emp (empno, ename ,job ,mgr ,hiredate ,sal ,comm ,deptno ) VALUES ((START+i) ,rand_string(6),'SALESMAN',0001,CURDATE(),2000,400,rand_num());  
 UNTIL i = max_num  
 END REPEAT;  
 COMMIT;  
 END $$

--随机产生部门编号
DELIMITER $$
CREATE FUNCTION rand_num( ) 
RETURNS INT(5)  
BEGIN   
 DECLARE i INT DEFAULT 0;  
 SET i = FLOOR(100+RAND()*10);  
RETURN i;  
 END $$
--随机生成字符串
DELIMITER $$
CREATE FUNCTION rand_string(n INT) RETURNS VARCHAR(255)
BEGIN
 DECLARE chars_str VARCHAR(100) DEFAULT 'abcdefghijklmnopqrstuvwxyzABCDEFJHIJKLMNOPQRSTUVWXYZ';
 DECLARE return_str VARCHAR(255) DEFAULT '';
 DECLARE i INT DEFAULT 0;
 WHILE i < n DO
 SET return_str =CONCAT(return_str,SUBSTRING(chars_str,FLOOR(1+RAND()*52),1));
 SET i = i + 1;
 END WHILE;
 RETURN return_str;
END $$

--当开启二进制日志后(可以执行SHOW VARIABLES LIKE 'log_bin'查看是否开启)，
--show VARIABLES LIKE 'log_bin_trust_function_creators'; 
--开启二进制日志
SET GLOBAL log_bin_trust_function_creators=1;

7中join:

--1 A、B两表共有
 SELECT * FROM tbl_emp a INNER JOIN tbl_dept b ON a.deptId = b.id;
 
--2 A、B两表共有+A的独有
 SELECT * FROM tbl_emp a LEFT JOIN tbl_dept b ON a.deptId = b.id;
 
--3 A、B两表共有+B的独有
 SELECT * FROM tbl_emp a RIGHT JOIN tbl_dept b ON a.deptId = b.id;
 
--4 A的独有 
SELECT * FROM tbl_emp a LEFT JOIN tbl_dept b ON a.deptId = b.id WHERE b.id IS NULL; 
 
--5 B的独有
 SELECT * FROM tbl_emp a RIGHT JOIN tbl_dept b ON a.deptId = b.id WHERE a.deptId IS NULL; #B的独有
 
--6 AB全有
#MySQL Full Join的实现 因为MySQL不支持FULL JOIN,下面是替代方法
 #left join + union(可去除重复数据)+ right join
SELECT * FROM tbl_emp A LEFT JOIN tbl_dept B ON A.deptId = B.id
UNION
SELECT * FROM tbl_emp A RIGHT JOIN tbl_dept B ON A.deptId = B.id
 
--7 A的独有+B的独有
SELECT * FROM tbl_emp A LEFT JOIN tbl_dept B ON A.deptId = B.id WHERE B.`id` IS NULL
UNION
SELECT * FROM tbl_emp A RIGHT JOIN tbl_dept B ON A.deptId = B.id WHERE A.`deptId` IS NULL;