can't create a table in mysql with dynamic sql - mysql

This is my code in MySQL.
USE database;
DROP procedure IF EXISTS CreateTable;
DELIMITER $$
USE ims_data$$
CREATE PROCEDURE CreateTable ()
BEGIN
Set #SqlQuery = Concat('DROP TABLE IF EXISTS mytemptable;');
Set #SqlQuery = Concat(#SqlQuery,'\r\n','create table mytemptable');
Set #SqlQuery = Concat(#SqlQuery,'\r\n','(');
Set #SqlQuery = Concat(#SqlQuery,'\r\n','Column1 int,');
Set #SqlQuery = Concat(#SqlQuery,'\r\n','Column2 varchar(500)');
Set #SqlQuery = Concat(#SqlQuery,'\r\n',');');
Set #SqlQuery = Concat(#SqlQuery,'\r\n','Select * from mytemptable;');
#Select #SqlQuery;
PREPARE Statement From #SqlQuery;
EXECUTE Statement;
DEALLOCATE PREPARE Statement;
END$$
DELIMITER ;
call GetUploadInformation();
I am trying to create a table but it is giving me an error.
Error Code: 1064. 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 'create table mytemptable (Stockist_Code int,Status varchar(500) ); Sele' at line 2
This is the output of query.
DROP TABLE IF EXISTS mytemptable;
create table mytemptable
(
Column1 int,
Column2 varchar(500)
);
Select * from mytemptable;
Which is working fine when executing this code withoug calling the procedure.

PREPARE/EXECUTE can only process one statement at a time. You're trying to execute two with the ;.
The error message gives you a clue in that it ran the two statements together.
You'll have to run them as separate statements.

Related

Syntax problem of bacth sql execution in procedure

Failed to run followwing code in mysql 8.0.
drop table if exists test ;
create table if not exists test(rowid int);
delimiter$$
drop procedure if exists line_sum $$
create procedure line_sum()
begin
declare i int ;
declare exe_sql varchar(100);
set i=5 ;
while i>0 do
set exe_sql = concat('alter table test add column d ',i,' int') ;
prepare ppsql from exe_sql ;
execute ppsql ;
deallocate prepare ppsql ;
set i = i-1;
end while ;
end$$
delimiter ;
It reported:
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 'while i>0 do
set exe_sql = concat('alter table test add column d ',i,' int'
at line 11
However my colleague and I have checked it many times, finding no issues in the syntax and getting more confusion.

Syntax Error in MySQL Dynamic Query

I've been facing this issue in MySQL since a long time. I've a dynamic query as below in my stored procedure,
delimiter //
CREATE PROCEDURE test_proc ()
BEGIN
DECLARE var INT DEFAULT 1;
DECLARE id VARCHAR(500) DEFAULT '0';
WHILE var <= 10
DO
SET id = CONCAT(id ,',',(SELECT CAST(id AS CHAR) FROM test_client WHERE Rank = var));
SET var = var + 1;
END WHILE;
SET SQL_QUERY = CONCAT('
CREATE TEMPORARY TABLE t1
AS
SELECT *
FROM test WHERE id IN (',id,');');
SET SQL_QUERY1 = CONCAT('
CREATE TEMPORARY TABLE t2
AS
SELECT *
FROM test1 WHERE id IN (',id,')');
SET #SWV_Stmt = CONCAT(SQL_QUERY,SQL_QUERY1);
PREPARE SWT_Stmt FROM #SWV_Stmt;
EXECUTE SWT_Stmt;
DEALLOCATE PREPARE SWT_Stmt;
END //
delimiter ;
When I create and execute this, I get below error,
Error Code: 1064. 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 'CREATE TEMPORARY TABLE t2 AS SELECT *' at line 5
Can anyone please provide a reason and solution for this?
Thanks in Advance...
That's not a single statement, that is two. The documentation states:
The text must represent a single statement, not multiple statements.

Mysql insert from stored procedure gives error 1064

For some strange reason, inserting from stored procedure is not working.
This is what Im trying to do:
DROP TABLE IF EXISTS test;
CREATE TABLE IF NOT EXISTS test(
id INT(9) NOT NULL AUTO_INCREMENT
,name VARCHAR(30) NOT NULL
,PRIMARY KEY (id)
) DEFAULT CHARSET=utf8;
insert into test (name) values('A');
Inserting from command line works with no problems.
Then I created a stored procedure to do the same kind of insert:
DROP PROCEDURE IF EXISTS storedtest;
DELIMITER $$
CREATE PROCEDURE storedtest()
BEGIN
declare insert_sql varchar(200);
SET insert_sql = 'insert into test (name) values(3)';
SELECT insert_sql;
PREPARE mystm FROM #insert_sql;
EXECUTE mystm;
END$$
DELIMITER ;
call storedtest();
This gives me the error:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'NULL' at line 1
NULL? Where did NULL came from?
I also tried changing the sql-insert to look like this (dont know if it is a good way):
SET insert_sql = "insert into test (name) values('3')";
But mysql gives me exactly the same error.
Anyone has a clue?
The NULL MySQL is reporting is an empty user variable #insert_sql, which is different from the local stored procedure local variable insert_sql which you allocated with DECLARE.
MySQL's DECLARE is used for variables local to a stored program, but according to the documentation, PREPARE stmt FROM ... expects either a string literal or a user variable, which are the type preceded with #.
PREPARE stmt_name FROM preparable_stmt
preparable_stmt is either a string literal or a user variable that contains the text of the SQL statement.
You can allocate the untyped user variable with SET so there is no need for DECLARE. You may wish to set it to NULL when you're finished.
DROP PROCEDURE IF EXISTS storedtest;
DELIMITER $$
CREATE PROCEDURE storedtest()
BEGIN
-- Just SET the user variable
SET #insert_sql = 'insert into test (name) VALUES (3)';
SELECT #insert_sql;
-- Prepare & execute
PREPARE mystm FROM #insert_sql;
EXECUTE mystm;
-- Deallocate the statement and set the var to NULL
DEALLOCATE PREPARE mystm;
SET #insert_sql = NULL;
END$$
DELIMITER ;

MySQL: prepared Statement in a stored Procedure - parameter error 1064

I'm creating a sql script for a migration functionality of ours. We want to migrate data from one magento-instance to another (using pure SQL because the import/export of magento is pretty limited).
One of the challenges ist that I want to dynamically alter the AUTO_INCREMENT value of a table so it doesn't need to be done manually in multiple steps. I want to set the AUTO_INCREMENT value to the current-maximum value of the corresponding column + 1.
I prepared the following stored procedure for this:
DELIMITER $$
CREATE PROCEDURE alter_auto_inc_customer()
BEGIN
SELECT #max := MAX(entity_id)+ 1 FROM customer_entity;
PREPARE stmt FROM 'ALTER TABLE customer_entity AUTO_INCREMENT = ?';
EXECUTE stmt USING #max;
END $$
This command runs smoothly. Afterwards the procedure should just be called by a simple statement:
CALL alter_auto_inc_customer();
When I execute the "call"-statement, I get a 1064 Syntax error. It's probably trivial but I can't figure it out for the life of me...
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 '?' at line 1
Does anyone have an idea what the issue is?
I need to get this into one or more stored procedures because I need to be able to run similar statements for multiple tables in the database.
Instead of altering the table structure you can use a trigger to get the max value + 1 before insert data:
DELIMITER $$
DROP TRIGGER IF EXISTS custom_autoincrement_bi$$
CREATE TRIGGER custom_autoincrement_bi BEFORE INSERT ON customer_entity
FOR each ROW
BEGIN
SET NEW.entity_id = select max(entity_id) + 1 from customer_entity;
END$$
DELIMITER ;
But if you want to alter the table from stored procedure
DELIMITER $$
CREATE PROCEDURE alter_auto_inc_customer()
BEGIN
SELECT MAX(entity_id) + 1 into #max FROM customer_entity;
set #sql = concat('ALTER TABLE customer_entity AUTO_INCREMENT = ', #max);
PREPARE stmt FROM #sql;
EXECUTE stmt ;
DEALLOCATE PREPARE stmt;
END $$

MySQL ALTER TABLE with arguments in stored procedure

In a MySQL migration script, I'm trying to drop all the foreign keys of a table without knowing the name of the constraints themselves. I need this because I can only be aware of the constraints names in a particular database installation, but the script has to work also in other installations where the name is unknown at current script coding time.
Here is my first guess of a stored procedure, but it doesn't work. In particular it complains about the '?' in ALTER TABLE.
DELIMITER $$
DROP PROCEDURE IF EXISTS drop_foreign_key_documents $$
CREATE PROCEDURE drop_foreign_key_documents ( )
BEGIN
WHILE (SELECT COUNT(*) AS index_exists FROM `information_schema`.`TABLE_CONSTRAINTS` c WHERE `c`.`CONSTRAINT_TYPE` LIKE '%FOREIGN%' AND `c`.`TABLE_NAME`='documents' and `c`.`TABLE_SCHEMA`='mydb') > 0 DO
SET #ctype = '%FOREIGN%';
SET #tname = 'documents';
SET #dbname = 'mydb';
SET #n = 'select `CONSTRAINT_NAME` INTO #cname FROM `information_schema`.`TABLE_CONSTRAINTS` c WHERE `c`.`CONSTRAINT_TYPE` LIKE ? AND `c`.`TABLE_NAME`=? and `c`.`TABLE_SCHEMA`=? LIMIT 0,1';
PREPARE stmt FROM #n;
EXECUTE stmt USING #ctype,#tname,#dbname;
SELECT #cname;
SET #s = 'ALTER TABLE `documents` DROP FOREIGN KEY ?';
PREPARE stmtd FROM #s;
EXECUTE stmtd USING #cname;
END WHILE;
END $$
DELIMITER ;
CALL drop_foreign_key_documents;
The output of MySQL is:
#cname
documents_ibfk_13
ERROR 1064 (42000) at line 23: 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 '?' at line 1
Now I can imagine why it complains: the ALTER TABLE statement cannot use '?' because the constraint name is not part of a WHERE clause and so it cannot be replaced by a positional parameter. What I don't know is how to build a parametrized ALTER TABLE statement.
Obvious answer:
SET #s = CONCAT('ALTER TABLE `documents` DROP FOREIGN KEY ', #cname);
PREPARE stmtd FROM #s;
EXECUTE stmtd;