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Re: Stored procedure - variabile per creazione tabella
Posted by: stefano fulgenzi
Date: November 12, 2018 06:08AM

Ciao,
per effettuare il passaggio di una variabile nella creazione del nome tabella (ma anche per altri statement), devi utilizzare l'istruzione di PREPARE.

---------------------
DROP PROCEDURE IF EXISTS `table_new`;

DELIMITER $$


CREATE DEFINER=`root`@`localhost` PROCEDURE `table_new`()
BEGIN
-- declare variables
DECLARE name_table varchar(15);

-- setting statement
SET @name_table=MONTHNAME(NOW());
SET @table = CONCAT('CREATE TABLE `',@name_table,'` (
`TimeLog` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
`Zona` varchar(22) NOT NULL,
`Sensore` varchar(20) NOT NULL,
`T` float NOT NULL,
`U` float NOT NULL,
KEY `TimeLog` (`TimeLog`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;');

PREPARE stmt from @table;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;


END
$$

---------------------

mysql> call table_new();
Query OK, 0 rows affected (0,01 sec)

mysql> show tables;
+-------------------+
| Tables_in_vulcano |
+-------------------+
| november |
+-------------------+
1 row in set (0,00 sec)

mysql> show create table november\G
*************************** 1. row ***************************
Table: november
Create Table: CREATE TABLE `november` (
`TimeLog` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
`Zona` varchar(22) NOT NULL,
`Sensore` varchar(20) NOT NULL,
`T` float NOT NULL,
`U` float NOT NULL,
KEY `TimeLog` (`TimeLog`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0,02 sec)

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Re: Stored procedure - variabile per creazione tabella
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November 12, 2018 06:08AM


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