I am trying to get this query to work
delimiter //
CREATE PROCEDURE test2(IN tbl CHAR(64), IN col CHAR(64))
BEGIN
SET #s = CONCAT('SELECT ',col,' FROM ',tbl );
PREPARE stmt FROM #s;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END
//
delimiter ;
This is the code used to call it
CALL test2(groups,NAME)
And this is the error I get:
1 Unknown column 'groups' in 'field list' SQL2.sql 1 12
The table name is groups, and the column name is NAME - Why is this not working
Well, you have written a stored procedure that takes character strings, and you have passed identifiers.
Try calling it thusly:
CALL test2('groups', 'NAME')
Related
I am trying to figure out how I can pass part of a table name into a stored procedure and get it to work.
query is
DELIMITER $$
DROP PROCEDURE IF EXISTS vorpaldev.searchLogId2$$
CREATE DEFINER = 'root'#'%'
PROCEDURE vorpaldev.searchLogId2 (userId varchar(300))
BEGIN
SET userId = CONCAT("log", userId);
SET #statment = "Select * from #userId ";
PREPARE stmt FROM #statment;
SET #a = userId;
EXECUTE stmt USING #a;
DEALLOCATE PREPARE stmt;
END
$$
DELIMITER
;
I am using
CALL searchLogId2 (131)
to call the code
I want the end results to execute as
Select * from log131
Well! are you going to create seperate table for each user????????? If yes, that is really bad.
I don't know but may be this is your answer. Why dont you pass complete userId in parameter argument 'log131' as
BEGIN
SET #statment = concat('Select * from ',userId);
PREPARE stmt FROM #statment;
EXECUTE stmt USING userId;
DEALLOCATE PREPARE stmt;
END
this will remove overhead of concat
Delimiter //
CREATE Procedure SearchTest(IN FieldName varchar(30),IN FieldValue varchar(30))
BEGIN
SET #query = CONCAT('select count(*) from Some_table_name where ', FieldName,'=',FieldValue);
PREPARE stmt FROM #query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END //
Delimiter ;
mysql> call SearchTest('accession_no','L138362194');
ERROR 1054 (42S22): Unknown column 'L138362194' in 'where clause'
Your database table does not have a column L138362194.
You can fix that by adding such a column, or by choosing a column that exists.
The error is generated because of missing quotes. Here is an SQL Fiddle that demonstrates the problem.
Modify the stored procedure:
DELIMITER //
CREATE PROCEDURE SearchTest(IN FieldName VARCHAR(30), IN FieldValue VARCHAR(30))
BEGIN
SET #query = CONCAT('SELECT COUNT(*) FROM `some_table_name` WHERE ', FieldName, ' = \'', FieldValue, '\';');
PREPARE stmt FROM #query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END //
DELIMITER ;
Here is my code
Drop procedure if exists test//
CREATE PROCEDURE test(IN woeid VARCHAR(15))
BEGIN
SET #w1 := woeid;
SET #sql = CONCAT('CREATE OR REPLACE VIEW temp
AS
SELECT *
FROM test_table gp
WHERE gp.name =', #w1);
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END//
Delimiter ;
call test('ABCD');
I am getting error as
Error code: 1054. Unknown column 'ABCD' in 'where' clause
Please help.
It sounds as though you're needlessly using views, when some other approach would be more appropriate.
However, the reason it isn't working is that you haven't quoted your string literal, so the resulting SQL contains WHERE gp.name = ABCD whereas it at very least needs to be WHERE gp.name = 'ABCD'. You can use MySQL's QUOTE() function for this purpose, but it's better to parameterise the value:
DELIMITER //
DROP PROCEDURE IF EXISTS test//
CREATE PROCEDURE test(IN woeid VARCHAR(15))
BEGIN
SET #w1:=woeid, #sql:=CONCAT('
CREATE OR REPLACE VIEW temp AS
SELECT *
FROM test_table
WHERE name = ?
');
PREPARE stmt FROM #sql;
EXECUTE stmt USING #w1;
DEALLOCATE PREPARE stmt;
SET #w1:=NULL, #sql:=NULL;
END//
DELIMITER ;
CALL test('ABCD');
I have the following stored procedure:
DELIMITER ///
CREATE PROCEDURE tmp_test_proc(__TABLE__NAME varchar(255))
BEGIN
SELECT COUNT(*) FROM __TABLE__NAME;
END///
DELIMITER ;
I would like to select from the parameter __TABLE__NAME, but MySQL tells me there is no table __TABLE__NAME... So is there a way to use the value of the parameter in the from clause?
you cannot parameterized table names (as well as column names) by default, you need to create PreparedStatement for this,
DELIMITER ///
CREATE PROCEDURE tmp_test_proc(__TABLE__NAME varchar(255))
BEGIN
SET #sql = CONCAT('SELECT COUNT(*) FROM ', __TABLE__NAME);
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END///
DELIMITER ;
I am stuck in Mysql today with the dynamic column name need in mysql select statement. Let me explain:
sql> select name1 from namescollection.
sql> select name2 from namescollection.
sql> select name3 from namescollection.
So namescollection table has three columns having name1, name2, name3
I would like to query this table in my stored procedure being 1,2,3 as dynamic and would be passed as a variable, but on the simple sql too when i query:
SELECT concat('name','1') FROM `namescollection`
name1 ----- name1 rather fetching name1 field's value.
Can any suggest on this, the right function i need to use rather concat though I know its right to output name1 when I am calling concat but I want to use it as column name.
What you can do is use a prepared statement within your stored procedure which will allow you to execute a string query:
As a simple example:
DELIMITER //
CREATE PROCEDURE selname (IN col VARCHAR(20))
BEGIN
SET #sql = CONCAT('SELECT ', col, ' FROM tbl');
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END//
DELIMITER ;
Test it out with this SQLFiddle Demo
Dynamic column name in store procedure Update statement :
DELIMITER //
CREATE DEFINER=`root`#`localhost` PROCEDURE `selname`()
BEGIN
declare cl int ;
declare clvalue int ;
set cl=1;
SET clvalue=1;
while cl < 4 DO
SET clvalue=clvalue*cl;
SET #sql = CONCAT('update test set col',cl, '=',clvalue,' where id=1');
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
set cl=cl+1;
end while;
END //
DELIMITER ;