MySQL 5.5 建立儲存過程和函式

feelpurple發表於2016-05-24
執行CREATE PROCEDURE和CREATE FUNCTION語句需要CREATE ROUTINE許可權。

檢視neo使用者現有許可權


授權
mysql> grant create routine on fire.* to neo;
Query OK, 0 rows affected (0.12 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.02 sec)

建立儲存過程



注意:在命令列縮排時,不要用tab,要使用空格,否則會報下面的錯
DATE INNER MULTILINESTRING SET UNICODE warnings
DATEDIFF INNOBASE MULTILINESTRINGFROMTEXT SHA UNION
DATETIME INNODB MULTILINESTRINGFROMWKB SHA1 UNIQUE
DATE_ADD INOUT MULTIPOINT SHARE UNIQUE_USERS
-> Info;
->
Display all 903 possibilities? (y or n)

執行儲存過程


授權
mysql> grant execute on fire.* to neo;
Query OK, 0 rows affected (0.04 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)





也可以直接在Navicat裡面執行


編輯儲存過程


呼叫儲存過程




建立不含引數的儲存過程,和Oracle不同的是,儲存過程名字後面必須要有()

mysql> delimiter $$
mysql> create procedure proc_Subscribers_update()
    -> begin
    -> DECLARE v_count INT;
    -> select ifnull(max(a),0) into v_count from t2;
    -> while v_count < 2 do
    -> select concat('the maximum value is ',v_count);
    -> set v_count = v_count+1;
    -> end while;
    -> end$$
Query OK, 0 rows affected (0.06 sec)

建立包含傳入引數的儲存過程
delimiter $$
create procedure proc_Subscribers_update(IN v_fetch_cnt INT, IN v_sleep_secs INT)
begin
DECLARE v_count INT;
DECLARE v_times INT DEFAULT 1;
DECLARE v_max_value INT;
/*compute the times that the loop runs*/
select ceil(count(MSISDN))/v_fetch_cnt into v_count from tmp_Subscribers_01;
/*compute the maximum rows that have been already updated*/
WHILE v_times < v_count DO
select ifnull(max(id),0) into v_max_value from tmp_Subscribers_02;
if v_max_value < v_fetch_cnt * v_count then
SET v_times = 1 + floor(v_max_value/v_fetch_cnt);
update Subscribers s,tmp_Subscribers_01 t set s.LastAccessTimeStamp=1420066800
where s.MSISDN=t.MSISDN and t.id > v_max_value and t.id <= v_fetch_cnt * v_times;
/*record the processing rows*/
insert into tmp_Subscribers_02 select id, MSISDN, now() from tmp_Subscribers_01 where id = v_fetch_cnt * v_times;
select concat('The job',' has already updated ', v_fetch_cnt * v_times, ' rows..') as Info;
select sleep(v_sleep_secs);
end if;
commit;
END WHILE;
select concat('The job',' is ','finished!') as Info;
commit;
end$$

刪除儲存過程


需要授予alter routine許可權

mysql> grant alter routine on fire.* to neo;
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)



在mysql客戶端中建立呼叫儲存過程

MariaDB [test]> delimiter //
MariaDB [test]> create procedure simpleproc(out param1 int)
    -> begin
    -> select count(*) into param1 from t;
    -> end//
Query OK, 0 rows affected (0.12 sec)
MariaDB [test]> delimiter ;
MariaDB [test]> CALL simpleproc(@a);
Query OK, 1 row affected (0.08 sec)
MariaDB [test]> select @a;
+------+
| @a   |
+------+
|    1 |
+------+
1 row in set (0.00 sec)

在呼叫的時候,如果引數不帶@,會報下面的
mysql> call proc_test(a,b);
ERROR 1414 (42000): OUT or INOUT argument 1 for routine test.proc_test is not a variable or NEW pseudo-variable in BEFORE trigger

檢視儲存過程的狀態

MariaDB [test]> show procedure status like 'simpleproc'\G
*************************** 1. row ***************************
                  Db: test
                Name: simpleproc
                Type: PROCEDURE
             Definer: root@localhost
            Modified: 2016-07-01 08:16:20
             Created: 2016-07-01 08:16:20
       Security_type: DEFINER
             Comment: 
character_set_client: utf8
collation_connection: utf8_general_ci
  Database Collation: utf8_general_ci
1 row in set (0.00 sec)

通過information_schema的檢視檢視儲存過程的相關資訊

MariaDB [test]> select * from information_schema.routines where routine_name='simpleproc'\G
*************************** 1. row ***************************
           SPECIFIC_NAME: simpleproc
         ROUTINE_CATALOG: def
          ROUTINE_SCHEMA: test
            ROUTINE_NAME: simpleproc
            ROUTINE_TYPE: PROCEDURE
               DATA_TYPE: 
CHARACTER_MAXIMUM_LENGTH: NULL
  CHARACTER_OCTET_LENGTH: NULL
       NUMERIC_PRECISION: NULL
           NUMERIC_SCALE: NULL
      DATETIME_PRECISION: NULL
      CHARACTER_SET_NAME: NULL
          COLLATION_NAME: NULL
          DTD_IDENTIFIER: NULL
            ROUTINE_BODY: SQL
      ROUTINE_DEFINITION: begin
select count(*) into param1 from t;
end
           EXTERNAL_NAME: NULL
       EXTERNAL_LANGUAGE: NULL
         PARAMETER_STYLE: SQL
        IS_DETERMINISTIC: NO
         SQL_DATA_ACCESS: CONTAINS SQL
                SQL_PATH: NULL
           SECURITY_TYPE: DEFINER
                 CREATED: 2016-07-01 08:16:20
            LAST_ALTERED: 2016-07-01 08:16:20
                SQL_MODE: NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
         ROUTINE_COMMENT: 
                 DEFINER: root@localhost
    CHARACTER_SET_CLIENT: utf8
    COLLATION_CONNECTION: utf8_general_ci
      DATABASE_COLLATION: utf8_general_ci
1 row in set (0.00 sec)

檢視儲存過程的定義

MariaDB [test]> show create procedure simpleproc\G
*************************** 1. row ***************************
           Procedure: simpleproc
            sql_mode: NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
    Create Procedure: CREATE DEFINER=`root`@`localhost` PROCEDURE `simpleproc`(out param1 int)
begin
select count(*) into param1 from t;
end
character_set_client: utf8
collation_connection: utf8_general_ci
  Database Collation: utf8_general_ci
1 row in set (0.00 sec)

建立函式

MySQL的傳入引數不能設定預設值,否則會報錯
mysql> delimiter $$
mysql> CREATE FUNCTION format_selectQuery (THE_TABLE_NAME VARCHAR(75), THE_COLUMNS_NAME VARCHAR(75), THE_CONDITION VARCHAR(75) DEFAULT NULL) RETURNS VARCHAR(200) DETERMINISTIC
    -> BEGIN
    ->     /*SELECT concat(' WHERE ', THE_CONDITION) INTO @WHERE_CLAUSE;
   /*>     IF THE_CONDITION IS NULL THEN
   /*> SET @WHERE_CLAUSE = NULL;
   /*> END IF;
   /*>     RETURN concat('SELECT ', THE_COLUMNS_NAME, ' FROM ', THE_TABLE_NAME, @WHERE_CLAUSE);*/
    ->     RETURN 1;
    -> END $$
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DEFAULT '') RETURNS VARCHAR(200) DETERMINISTIC
BEGIN
    
    RETURN 1;
END' at line 1
mysql> delimiter ;

需要注意的是,在MySQL裡,建立函式中在函式宣告後面的返回關鍵字是RETURNS


執行函式





需要注意的是,函式或儲存過程裡面的引數宣告順序,順序有誤,容易引起語法報錯
delimiter $$
CREATE FUNCTION is_ChangeDescColumnExist (THE_VERSION_LEVEL_TABLE_NAME VARCHAR(35)) RETURNS INT DETERMINISTIC
    BEGIN
/* 宣告變數 */
    DECLARE nbr INT;
/* 宣告異常 */
    DECLARE CONTINUE HANDLER FOR NOT FOUND set nbr = 1;
/* 給變數賦值 */
    SET nbr =0;       
        select count(*) into nbr from information_schema.columns where table_name = THE_VERSION_LEVEL_TABLE_NAME and
        (column_name ='C_CHANGE_DESCRIPTION');
        IF nbr = 1 THEN
            RETURN 1;
        ELSE        
            RETURN 0;
        END IF;
    END$$
delimiter ;

將上面的順序放置錯誤,則會引起報錯
mysql> CREATE FUNCTION is_ChangeDescColumnExist (THE_VERSION_LEVEL_TABLE_NAME VARCHAR(35)) RETURNS INT DETERMINISTIC
    ->     BEGIN
    ->     DECLARE nbr INT;
    ->     SET nbr =0;
    ->     DECLARE CONTINUE HANDLER FOR NOT FOUND set nbr = 10;
    ->           
    ->         select count(*) into nbr from information_schema.columns where table_name = THE_VERSION_LEVEL_TABLE_NAME and
    ->         (column_name ='C_CHANGE_DESCRIPTION');
    ->         IF nbr = 1 THEN
    ->             RETURN 1;
    ->         ELSE
ELSE    ELSEIF  
    ->         ELSE
    ->             RETURN 0;
    ->         END IF;
    ->     END$$
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DECLARE CONTINUE HANDLER FOR NOT FOUND set nbr = 10;
          
        select c' at line 5

建立兩個函式,返回兩種變數,一種是DECLARE變數,一種是@變數
delimiter $$
    CREATE FUNCTION is_TableMigrated (THE_VERSION_LEVEL_TABLE_NAME VARCHAR(20)) RETURNS INTEGER DETERMINISTIC
    BEGIN
    DECLARE nbr integer;
    SET nbr =222;
RETURN nbr;
END$$
delimiter ;

delimiter $$
    CREATE FUNCTION is_TableMigrated (THE_VERSION_LEVEL_TABLE_NAME VARCHAR(20)) RETURNS INTEGER DETERMINISTIC
    BEGIN
    DECLARE nbr integer;
    SET @nbr2 =22222;
RETURN @nbr2;
END$$
delimiter ;

來自 “ ITPUB部落格 ” ,連結:http://blog.itpub.net/26506993/viewspace-2106133/,如需轉載,請註明出處,否則將追究法律責任。

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