I am trying to write a mysql program, which has cursors in it. Due to an error in writing an DECLARE query, MySQL Workbench is always showing me the DECLARE is not valid at this position, expected EOF, ALTER, ANALYZE, BEGIN, BINLOG, CACHE, ...
Could you help me solve this problem?
Here is my code:
DELIMITER //
BEGIN
declare Naslov_knjige VARCHAR(24);
declare Cena_knjige DECIMAL(8,2);
DECLARE cursor_cene CURSOR
FOR SELECT
Naslov,
Cena
FROM
prvi_test_v2.knjige;
OPEN cursor_cene //
FETCH NEXT FROM cursor_cene INTO
#Naslov_knjige,
#Cena_knjige //
WHILE ##FETCH_STATUS = 0
BEGIN
PRINT #Naslov_knjige + CAST(#Cena_knjige AS VARCHAR) //
FETCH NEXT FROM cursor_cene INTO
#Naslov_knjige,
#Cena_knjige //
END //
CLOSE cursor_cene //
DEALLOCATE cursor_cene //
END //
DELIMITER ;
Thanks for your help!
I will assume you omitted a line for CREATE PROCEDURE, because in MySQL a BEGIN...END block must be part of a stored routine. See https://dev.mysql.com/doc/refman/8.0/en/begin-end.html
BEGIN ... END syntax is used for writing compound statements, which can appear within stored programs (stored procedures and functions, triggers, and events).
You changed the DELIMITER:
DELIMITER //
Using this delimiter terminates the whole CREATE PROCEDURE statement. You should not do this after the first statement in the body of the procedure. You need to use the normal ; terminators for each statement within the body of the procedure. The reason for changing the delimiter is so you can use ; for each statement in the procedure without ending the CREATE PROCEDURE.
See examples and documentation here: https://dev.mysql.com/doc/refman/8.0/en/stored-programs-defining.html
That's the reason for the error you got. You used // to terminate OPEN cursor_cene // which ended the CREATE PROCEDURE, but clearly there was more to that procedure.
There are other problems with your procedure. You seem to be using Microsoft SQL Server syntax, but MySQL is different.
Naslov_knjige is not the same variable as #Naslov_knjige in MySQL. Don't use the # sigil in front of local variables. If you use the # sigil, this refers to a user-defined variable.
The WHILE ##FETCH_STATUS = 0 syntax is specific to Microsoft SQL Server. MySQL has different syntax for running a cursor loop. See example in the documentation: https://dev.mysql.com/doc/refman/8.0/en/cursors.html
That's as far as I got. There may be more problems, but I am not going to look for them.
Related
In my model I defined some procedures. The code (generated by MySQL Workbench) contains DELIMITER definitions, so the procedures look like:
-- schema
CREATE DATABASE ...
CREATE TABLE foo ...
-- procedures
DELIMITER $$
...
BEGIN
DECLARE ... ;
OPEN ... ;
SET ... ;
... ;
END$$
DELIMITER ;
Now I need to "import" the SQL to the database via PDO. I tried to pass it as input for the PDO#exec(...), but noticed, that the execution stops on the line of the first DELIMITER definition.
I don't want remove the DELIMITER statements. So the the SQL code should remain the same.
How to use PDO to execute SQL code containing DELIMITER statements?
From comments:
I don't want remove the DELIMITER statements. And actually I want to get it working without to execute every statement manually
That's not how it works.
To understand why, you need to understand how the mysql CLI -- and any other program that can read and execute a dump file like this -- actually handles it.
DELIMITER is not something the server understands.
DELIMITER is used to tell the client-side parser what the current statement delimiter should be, so that the client-side parser can correctly split the statements and deliver one at a time to the server for execution.
From the docs. Note carefully that mysql, every time it is used here, refers to the mysql client utility -- not the server.
If you use the mysql client program to define a stored program containing semicolon characters, a problem arises. By default, mysql itself recognizes the semicolon as a statement delimiter, so you must redefine the delimiter temporarily to cause mysql to pass the entire stored program definition to the server.
To redefine the mysql delimiter, use the delimiter command. [...] The delimiter is changed to // to enable the entire definition to be passed to the server as a single statement, and then restored to ; before invoking the procedure. This enables the ; delimiter used in the procedure body to be passed through to the server rather than being interpreted by mysql itself.
https://dev.mysql.com/doc/refman/5.7/en/stored-programs-defining.html
So, to handle such a file, you need a client-side parser that does the same thing mysql does... and here, the code you are writing is (needs to be) the client-side statement parser. So you are the one that needs to write the logic to handle the delimiter.
To do what you want, you have to interpret the DELIMITER statements, use them to keep track of the current statement delimiter, but do not send them to the server.
Then, you have to read through the input one line at a time, buffering what you've read, until you find the specified delimiter at the end of the line, and send the resulting statement to the server -- excluding the actual statement delimiter from what you send... so, for example, you would not send the ending $$ after the procedure body (unless the current statement delimiter is ;, which you can either send or not send -- the server doesn't care.) Then empty the buffer and start reading again until you see another instance of a delimiter (and send the statement to the server) or match a DELIMITER statement and set your code's current delimiter variable to match it so that you correctly identify the end of the next statement.
Delimiters is a thing that you don't need with PDO. You can just run your queries as is
$pdo->query("CREATE DATABASE ...");
$pdo->query("CREATE TABLE foo ...");
$pdo->query("BEGIN
DECLARE ... ;
OPEN ... ;
SET ... ;
... ;
END");
as simple as that
I met same problem with you when I tried with PostgreSQL. The problem seems PDO just allow you execute 1 query 1 time. As mentioned: PDO::exec() executes an SQL statement in a single function call, returning the number of rows affected by the statement. In php manual
Could you try this:
$stmt = $db->prepare($sql);
$stmt->execute();
Or with mysqli: multi_query. php manual
Here my whole class: http://sandbox.onlinephpfunctions.com/code/f0528fda6d7bd097c3199f1f3c019805a163ae3a
Very new to the environment, I have a question about a line that's added to the end of my code. The guide I'm following is:
http://net.tutsplus.com/tutorials/an-introduction-to-stored-procedures/
If anyone has a better one regarding MySQL stored procedures, I'm all ears.
Before I ask, this is the environment I'm using:
OS: Windows 7 / WAMP (MySQL 5.5.24) / MySQL Workbench
I'm instructed to define a delimiter; in my case I'm sticking with the default '$$.'
The stored procedure I created is:
DELIMITER $$
CREATE PROCEDURE test.`p2` ()
LANGUAGE SQL
DETERMINISTIC
COMMENT 'Adds "nson" to first and last names in the record.'
BEGIN
SELECT 'Hello World';
END $$
When I apply this stored procedure and I get the review screen, I see a new line of code added;
At the bottom:
DELIMITER ;
This lats line; is it added because the DELIMITER statement announces a block within which the defined delimiters ($$) can be used and thus closes the block in the end?
When using the builtin procedure editor, MySQL Workbench adds a few extra commands:
USE `test`; // <----------
DROP procedure IF EXISTS `p2`; // <----------
DELIMITER $$
USE `test`$$ // <----------
CREATE PROCEDURE test.`p2` ()
LANGUAGE SQL
DETERMINISTIC
COMMENT 'Adds "nson" to first and last names in the record.'
BEGIN
SELECT 'Hello World';
END $$
DELIMITER ; // <----------
Those commands are not strictly related to the stored procedures syntax, they're merely a commodity—other MySQL clients (such as HeidiSQL or the official command line utility) will not add them. The last delimiter change is probably a reset to avoid problems in future statements on the same connection.
You need to change the delimiter in order to instruct the client about where the procedure code starts and end. The problem is that the procedure body is normally a collection of SQL statements so omitting the delimiter change would make MySQL think that you are attempting to run a series of statements, the first of which would be this:
CREATE PROCEDURE test.`p2` ()
LANGUAGE SQL
DETERMINISTIC
COMMENT 'Adds "nson" to first and last names in the record.'
BEGIN
SELECT 'Hello World';
With DELIMITER $$ you are telling MySQL that your full statement goes from CREATE to END. It's just syntactic sugar: DELIMITER is not even a SQL keyword. HeidiSQL, for instance, provides a GUI with a text box where you write the procedure body, thus you don't need the DELIMITER workaround.
My question may sound lame but still I cant get whats wrong with this code. I have made a stored procedure in sqlyog and now I want to call it. I have tried almost everything but it doesn't work.
SET #x=1;
WHILE #x<=10 DO
CALL mypro();
SET #x=#x+1;
END WHILE;
Thanks in advance.
Flow control statements like IF, WHILE need to be executed in context of a function or stored procedure. If you wish to execute mypro() in a loop, that action itself must be created as a procedure. Below I will create a procedure called call_mypro_x10() which calls your original stored procedure in a WHILE loop.
DELIMITER $$
CREATE PROCEDURE call_mypro_x10()
BEGIN
SET #x = 1;
WHILE #x <= 10 DO
CALL mypro();
SET #x := #x + 1;
END WHILE;
END$$
DELIMITER ;
Then call this procedure which wraps the other one:
CALL call_mypro_x10();
Note that the DELIMITER statements may not be necessary in all clients, and some MySQL clients supply a different method of specifying an alternate delimiter needed in stored procedure and function definitions. Apparently SQLyog supports DELIMITER
There is an open feature request to permit flow control statements as part of normal query execution.
Very new to the environment, I have a question about a line that's added to the end of my code. The guide I'm following is:
http://net.tutsplus.com/tutorials/an-introduction-to-stored-procedures/
If anyone has a better one regarding MySQL stored procedures, I'm all ears.
Before I ask, this is the environment I'm using:
OS: Windows 7 / WAMP (MySQL 5.5.24) / MySQL Workbench
I'm instructed to define a delimiter; in my case I'm sticking with the default '$$.'
The stored procedure I created is:
DELIMITER $$
CREATE PROCEDURE test.`p2` ()
LANGUAGE SQL
DETERMINISTIC
COMMENT 'Adds "nson" to first and last names in the record.'
BEGIN
SELECT 'Hello World';
END $$
When I apply this stored procedure and I get the review screen, I see a new line of code added;
At the bottom:
DELIMITER ;
This lats line; is it added because the DELIMITER statement announces a block within which the defined delimiters ($$) can be used and thus closes the block in the end?
When using the builtin procedure editor, MySQL Workbench adds a few extra commands:
USE `test`; // <----------
DROP procedure IF EXISTS `p2`; // <----------
DELIMITER $$
USE `test`$$ // <----------
CREATE PROCEDURE test.`p2` ()
LANGUAGE SQL
DETERMINISTIC
COMMENT 'Adds "nson" to first and last names in the record.'
BEGIN
SELECT 'Hello World';
END $$
DELIMITER ; // <----------
Those commands are not strictly related to the stored procedures syntax, they're merely a commodity—other MySQL clients (such as HeidiSQL or the official command line utility) will not add them. The last delimiter change is probably a reset to avoid problems in future statements on the same connection.
You need to change the delimiter in order to instruct the client about where the procedure code starts and end. The problem is that the procedure body is normally a collection of SQL statements so omitting the delimiter change would make MySQL think that you are attempting to run a series of statements, the first of which would be this:
CREATE PROCEDURE test.`p2` ()
LANGUAGE SQL
DETERMINISTIC
COMMENT 'Adds "nson" to first and last names in the record.'
BEGIN
SELECT 'Hello World';
With DELIMITER $$ you are telling MySQL that your full statement goes from CREATE to END. It's just syntactic sugar: DELIMITER is not even a SQL keyword. HeidiSQL, for instance, provides a GUI with a text box where you write the procedure body, thus you don't need the DELIMITER workaround.
I often see people are using Delimiters. I tried myself to find out what are delimiters and what is their purpose. After 20 minutes of googling, I was not able to find an answer which satisfies me. So, my question is now: What are delimiters and when should I use them?
Delimiters other than the default ; are typically used when defining functions, stored procedures, and triggers wherein you must define multiple statements. You define a different delimiter like $$ which is used to define the end of the entire procedure, but inside it, individual statements are each terminated by ;. That way, when the code is run in the mysql client, the client can tell where the entire procedure ends and execute it as a unit rather than executing the individual statements inside.
Note that the DELIMITER keyword is a function of the command line mysql client (and some other clients) only and not a regular MySQL language feature. It won't work if you tried to pass it through a programming language API to MySQL. Some other clients like PHPMyAdmin have other methods to specify a non-default delimiter.
Example:
DELIMITER $$
/* This is a complete statement, not part of the procedure, so use the custom delimiter $$ */
DROP PROCEDURE my_procedure$$
/* Now start the procedure code */
CREATE PROCEDURE my_procedure ()
BEGIN
/* Inside the procedure, individual statements terminate with ; */
CREATE TABLE tablea (
col1 INT,
col2 INT
);
INSERT INTO tablea
SELECT * FROM table1;
CREATE TABLE tableb (
col1 INT,
col2 INT
);
INSERT INTO tableb
SELECT * FROM table2;
/* whole procedure ends with the custom delimiter */
END$$
/* Finally, reset the delimiter to the default ; */
DELIMITER ;
Attempting to use DELIMITER with a client that doesn't support it will cause it to be sent to the server, which will report a syntax error. For example, using PHP and MySQLi:
$mysqli = new mysqli('localhost', 'user', 'pass', 'test');
$result = $mysqli->query('DELIMITER $$');
echo $mysqli->error;
Errors with:
You have an error in your SQL syntax; check the manual that corresponds
to your MySQL server version for the right syntax to use near 'DELIMITER $$' at line 1
The DELIMITER statement changes the standard delimiter which is semicolon ( ;) to another. The delimiter is changed from the semicolon( ;) to double-slashes //.
Why do we have to change the delimiter?
Because we want to pass the stored procedure, custom functions etc. to the server as a whole rather than letting mysql tool to interpret each statement at a time.
When you create a stored routine that has a BEGIN...END block, statements within the block are terminated by semicolon (;). But the CREATE PROCEDURE statement also needs a terminator. So it becomes ambiguous whether the semicolon within the body of the routine terminates CREATE PROCEDURE, or terminates one of the statements within the body of the procedure.
The way to resolve the ambiguity is to declare a distinct string (which must not occur within the body of the procedure) that the MySQL client recognizes as the true terminator for the CREATE PROCEDURE statement.
You define a DELIMITER to tell the mysql client to treat the statements, functions, stored procedures or triggers as an entire statement. Normally in a .sql file you set a different DELIMITER like $$. The DELIMITER command is used to change the standard delimiter of MySQL commands (i.e. ;). As the statements within the routines (functions, stored procedures or triggers) end with a semi-colon (;), to treat them as a compound statement
we use DELIMITER. If not defined when using different routines in the same file or command line, it will give syntax error.
Note that you can use a variety of non-reserved characters to make your own custom delimiter. You should avoid the use of the backslash (\) character because that is the escape character for MySQL.
DELIMITER isn't really a MySQL language command, it's a client command.
Example
DELIMITER $$
/*This is treated as a single statement as it ends with $$ */
DROP PROCEDURE IF EXISTS `get_count_for_department`$$
/*This routine is a compound statement. It ends with $$ to let the mysql client know to execute it as a single statement.*/
CREATE DEFINER=`student`#`localhost` PROCEDURE `get_count_for_department`(IN the_department VARCHAR(64), OUT the_count INT)
BEGIN
SELECT COUNT(*) INTO the_count FROM employees where department=the_department;
END$$
/*DELIMITER is set to it's default*/
DELIMITER ;