I am trying to create a Procedure during the creation of a database, the mysql query is as follows:
CREATE DATABASE database_Sensor1;
USE database_Sensor1;
CREATE TABLE Persons(id int NOT NULL);
DELIMITER //
CREATE PROCEDURE MYLOOP() IF database_Sensor1 EXISTS
BEGIN
DECLARE i int;
DECLARE str varchar(255);
SET i = 0;
WHILE i < 32 DO
SET str = CONCAT('col_',i);
SET #sql = CONCAT('ALTER TABLE persons ADD ',str,' float;');
SET i = i + 1;
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END WHILE;
END
DELIMITER ;
CALL MYLOOP();
But I get this error:
#1305 - PROCEDURE database_sensor1.MYLOOP does not exist
I am trying to use the Procedure to Loop the table creation by quickly altering the table to add 32 columns in so that I can run another .php to add in the values.
CREATE DATABASE database_Sensor1;
USE database_Sensor1;
CREATE TABLE database_Sensor1.Persons(id int NOT NULL);
DELIMITER //
CREATE PROCEDURE database_Sensor1.MYLOOP()
BEGIN
DECLARE i int;
DECLARE str varchar(255);
SET i = 0;
WHILE i < 32 DO
SET str = CONCAT('col_',i);
SET #sql = CONCAT('ALTER TABLE database_Sensor1.persons ADD ',str,' float;');
SET i = i + 1;
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END WHILE;
END
//
DELIMITER ;
CALL MYLOOP();
Editions:
IF database_name EXISTS construction not exists. Removed. See edition 3.
Procedure creation code is not finalized with delimiter. Added.
The database in which the procedure must be created is not specified explicitly. Added. If the database not exists then the error will be generated. The same with the table name.
Related
I have two tables,
execution:
execution_id | order_id | execution_date
1 1 2014-03-16
2 1 2014-03-17
and queries:
query_name | code
CNT_EXEC | SELECT COUNT(execution_id) FROM `execution`
We have query defined in a column above. I am trying to execute this query using my code below;
DELIMITER //
DROP PROCEDURE IF EXISTS query_execute //
CREATE PROCEDURE query_execute()
BEGIN
DECLARE finished INTEGER DEFAULT 0;
DECLARE s_query varchar(255);
DECLARE c_queries CURSOR FOR
SELECT code FROM queries;/*since there are more than one queries in the actual query table*/
DECLARE CONTINUE HANDLER FOR NOT FOUND SET finished = 1;
OPEN c_queries;
getquery: LOOP
FETCH c_queries INTO s_query;
IF finished = 1 THEN
LEAVE getquery;
END IF;
/*run the query*/
SET #sql = s_query;
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END LOOP;
END //
DELIMITER ;
/*next I am trying to invoke the procedure and find the results*/
CREATE PROCEDURE queriesExecution()
BEGIN
SELECT query_name, query_execute() AS val
FROM queries;
END
Going by the MySQL documentation, it seems I am using the correct procedure to create the procedure.But here is the error I am getting;
ERROR 1064 (42000) in the pre-written template: 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 5`.
As i already wrote in my comment, your approach doesn't work .
But you can change it a bit
First:
Change your queries, because you need a result
CREATE TABLE queries (
`query_name` VARCHAR(8),
`code` VARCHAR(355)
);
INSERT INTO queries
(`query_name`, `code`)
VALUES
('CNT_EXEC', 'SELECT COUNT(execution_id) INTO #result FROM `execution`');
As you can see the result is put into a user defined variable. so that ot can be used in the INSERT INT myresult
DELIMITER //
DROP PROCEDURE IF EXISTS query_execute //
CREATE PROCEDURE query_execute()
BEGIN
DECLARE finished INTEGER DEFAULT 0;
DECLARE s_query varchar(255);
DECLARE c_queries CURSOR FOR
SELECT code FROM queries;/*since there are more than one queries in the actual query table*/
DECLARE CONTINUE HANDLER FOR NOT FOUND SET finished = 1;
CREATE TEMPORARY TABLe myresults(`query` varchar(255), result INT);
OPEN c_queries;
getquery: LOOP
FETCH c_queries INTO s_query;
IF finished = 1 THEN
LEAVE getquery;
END IF;
/*run the query*/
SET #sql = s_query;
PREPARE stmt FROM #sql;
EXECUTE stmt;
INSERT INTO myresults VALUES (s_query,#result);
DEALLOCATE PREPARE stmt;
END LOOP;
SELECT * FROM myresults;
DROP TEMPORARY TABLE myresults;
END //
DELIMITER ;
when you now call CALL query_execute();
you get
query result
SELECT COUNT(execution_id) INTO #result FROM `execution` 2
Of course as you add queries, you will get more rows.
this now assumes you get only INTEGER back in your queries, if not you must change the datatype.
This also only works, because your query returns only 1 result, if get more rows you can't use the user defined variables and you have to look for another approach.
Have anyone faced the same problem as mine ? please kindly help !!
I have two procedures and one event, the procedures are working just fine when I call them separately from the command line.
But those procedures can not be called from inside the mysql event.
Below are my procedures, mysql event and how I check the effective result:
USE ims_db;
DELIMITER;
DROP PROCEDURE IF EXISTS CreatePartition$$
CREATE PROCEDURE CreatePartition(day_keep_data INT)
BEGIN
DECLARE partition_temp TEXT;
DECLARE partition_name CHAR(12);
DECLARE partition_threshold INT DEFAULT 0;
DECLARE day_temp INT;
SET day_temp = day_keep_data;
SET #sql = concat('ALTER TABLE ims_db.ims_counter PARTITION BY RANGE(trigger_time)(');
loop_change_partition: LOOP
IF day_temp <= 0 THEN
LEAVE loop_change_partition;
END IF;
SET day_temp = day_temp - 1;
SET partition_threshold = UNIX_TIMESTAMP() - 86400*day_temp;
SET partition_name = concat('p', CURRENT_DATE() - INTERVAL day_temp DAY + 0);
SET partition_temp = concat('PARTITION', partition_name, ' VALUES LESS THAN (', partition_threshold,'), ');
SET #sql = concat(#sql, partition_temp);
END LOOP loop_change_partition;
SET partition_name = concat('p', CURRENT_DATE() + INTERVAL 1 DAY + 0);
SET partition_temp = concat('PARTITION', partition_name, ' VALUES LESS THAN MAXVALUE);');
SET #sql = concat(#sql, partition_temp);
prepare stmt from #sql;
execute stmt;
deallocate prepare stmt;
END$$
DELIMITER ;
DELIMITER $$
DROP PROCEDURE IF EXISTS DeleteOldData$$
CREATE PROCEDURE DeleteOldData(day_keep_data INT)
BEGIN
SET #sql = concat('DELETE FROM ims_db.ims_counter WHERE ims_db.ims_counter.id > 0
AND ims_db.ims_counter.trigger_time < ', UNIX_TIMESTAMP() - 86400*day_keep_data);
prepare stmt from #sql;
execute stmt;
deallocate prepare stmt;
ALTER TABLE ims_counter REMOVE PARTITIONING;
END$$
DELIMITER ;
-- DELIMITER $$
-- CREATE FUNCTION ims_daily_work() RETURNS INT(11)
-- BEGIN
-- CALL DeleteOldData(30);
-- CALL CreatePartition(30);
-- END $$
-- DELIMITER ;
DELIMITER $$
CREATE EVENT IMSDailyWork
ON SCHEDULE EVERY 30 SECOND STARTS CURRENT_TIMESTAMP + INTERVAL 10 SECOND
DO
BEGIN
CALL DeleteOldData(30);
CALL CreatePartition(30);
-- SELECT ims_daily_work();
END$$
DELIMITER ;
How I check the effective result:
run command: show table status like 'ims_counter'\G -> check Create_options: -> it is null
after running all the above event and procedures -> check again Create_options: -> it should be 'partitioned', but my problem is there's no such 'partitioned' like that.
I found the solution: it is because my 'event_scheduler' is OFF, so no EVENT can be launched.
to check event status: show global variables like 'event_scheduler';
to enable event_scheduler: set global event_scheduler=1;
I want to create multiple tables with just one statement (query).
Loop
start
(
create table a
)
a =a +1
end loop
So say it has to create 100 tables labeled as TABLE1, TABLE2, ...
Try the following procedure.
DROP PROCEDURE IF EXISTS `createTableProcTest`;
delimiter //
CREATE PROCEDURE `createTableProcTest`()
BEGIN
DECLARE count INT Default 0;
simple_loop: LOOP
SET #a := count + 1;
SET #statement = CONCAT('Create table Table',#a,' ( name VARCHAR(70), age int );');
PREPARE stmt FROM #statement;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET count = count + 1;
IF count=100 THEN
LEAVE simple_loop;
END IF;
END LOOP simple_loop;
END//
In order to execute just do the following:
Call createTableProcTest();
By executing the above procedure 100 tables will be created having name table1,...,table100.
And the table structure would look like following:
N:B: Procedure execution might take several seconds. Don't be impatient.
You need give us more details but, I think is easier to call a stored procedure, inside the loop, to create the procedure.
You need to create a procedure to create the tables you need and call this procedure inside the loop.
Ex:
CREATE PROCEDURE SP_Create_Table(IN tableName VARCHAR(50)) BEGIN SET
#sql = CONCAT('CREATE TABLE ', tableName, '(column1 INT(11))');
PREPARE stmt FROM #sql; EXECUTE stmt; DEALLOCATE PREPARE stmt; END
Now, call the create table procedure inside the loop
DELIMITER // CREATE FUNCTION CalcIncome ( starting_value INT ) RETURNS
INT BEGIN
DECLARE income INT; SET income = 0; label1: WHILE income <=
50 DO
call SP_Create_Table(CONVERT(VARCHAR(50),starting_value)); END WHILE label1; RETURN income; END; // DELIMITER;
I want the procedure to take parameter answertable and partid in the select statement,
but when i call it it doesn't replace the parameter answertable with the value
the call call updateTotalScores('quiz_participation', 'quiz_answer', 1)
returns the error: 1146 - Table 'quizdb.answertable' doesn't exist
passing the id works, but passing the table name doesn't
so how do i pass the table name to the select in
DECLARE cur1 CURSOR FOR SELECT SUM(`score`), SUM(`maxscore`) FROM answertable WHERE `idParticipation`=partid;
entire procedure:
DELIMITER $$
CREATE PROCEDURE updateTotalScores(IN participationtable CHAR(64), IN answertable CHAR(64), IN partid INT)
BEGIN
DECLARE done INTEGER DEFAULT 0;
DECLARE sscore INTEGER DEFAULT 0;
DECLARE smaxscore INTEGER DEFAULT 0;
DECLARE cur1 CURSOR FOR SELECT SUM(`score`), SUM(`maxscore`) FROM answertable WHERE `idParticipation`=partid;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
OPEN cur1;
REPEAT
FETCH cur1 INTO sscore, smaxscore;
UNTIL done = 1
END REPEAT;
CLOSE cur1;
UPDATE participationtable SET `score`=sscore, `maxscore`=smaxscore WHERE `idParticipation`=partid;
END $$
DELIMITER ;
For completeness
the table name cannot be passed to a MySql cursor, at least not yet
http://forge.mysql.com/worklog/task.php?id=3433
the answer from below (corrected a bit)
DELIMITER $$
CREATE PROCEDURE updateTotalScores(IN participation_table VARCHAR(45), IN answer_table VARCHAR(45), IN part_id INT)
BEGIN
SET #stmt_text=CONCAT("SELECT #score := SUM(`score`), #maxscore := SUM(`maxscore`) FROM ",
answer_table, " WHERE `idParticipation`=", part_id);
PREPARE stmt FROM #stmt_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET #stmt_text=CONCAT("UPDATE ", participation_table,
" SET `score`=?, `maxscore`=? WHERE `idParticipation`=", part_id);
PREPARE stmt FROM #stmt_text;
EXECUTE stmt USING #score, #maxscore;
DEALLOCATE PREPARE stmt;
END $$
I believe you cannot do it in this manner.
In order to achieve this, you should use Dynamic SQL.
Note that you cannot open a cursor using Dynamic SQL either. But in your case, there seems to be no need for a cursor.
If i understand your code correctly, you can just use user variables and probably achieve what you are trying to do using 2 Dynamically prepared statements.
SET #stmt_text=CONCAT("SELECT #score = SUM(`score`), #maxscore=SUM(`maxscore`) FROM ",
answertable, "WHERE `idParticipation`= ", partid);
PREPARE stmt FROM #stmt_text;
EXECUTE stmt USING #a;
And then you update the values using the below statement
SET #stmt_text=CONCAT("UPDATE", participationtable, " SET `score`=#score,
`maxscore`=#maxscore WHERE `idParticipation`=", partid);
PREPARE stmt FROM #stmt_text;
EXECUTE stmt USING #a;
DEALLOCATE PREPARE stmt;
Note: Please check the syntax. I cannot test it to verify it exactly but i hope you get the idea.
I need to use a variable to indicate what database to query in the declaration of a cursor. Here is a short snippet of the code :
CREATE PROCEDURE `update_cdrs_lnp_data`(IN dbName VARCHAR(25), OUT returnCode SMALLINT)
cdr_records:BEGIN
DECLARE cdr_record_cursor CURSOR FOR
SELECT cdrs_id, called, calling FROM dbName.cdrs WHERE lrn_checked = 'N';
# Setup logging
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
#call log_debug('Got exception in update_cdrs_lnp_data');
SET returnCode = -1;
END;
As you can see, I'm TRYING to use the variable dbName to indicate in which database the query should occur within. However, MySQL will NOT allow that. I also tried things such as :
CREATE PROCEDURE `update_cdrs_lnp_data`(IN dbName VARCHAR(25), OUT returnCode SMALLINT)
cdr_records:BEGIN
DECLARE cdr_record_cursor CURSOR FOR
SET #query = CONCAT("SELECT cdrs_id, called, calling FROM " ,dbName, ".cdrs WHERE lrn_checked = 'N' ");
PREPARE STMT FROM #query;
EXECUTE STMT;
# Setup logging
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
#call log_debug('Got exception in update_cdrs_lnp_data');
SET returnCode = -1;
END;
Of course this doesn't work either as MySQL only allows a standard SQL statement in the cursor declaration.
Can anyone think of a way to use the same stored procedure in multiple databases by passing in the name of the db that should be affected?
The answer of Vijay Jadhav is the right way to solve this limitation by MySQL. Actually, you need 3 proc to accomplish it:
proc1 using Vijay Jadhav's way, works like a data collector. You need to pass the variables to proc1 and let it create the tmp table for proc2. There is one limiation of Vijay's way, he should create a TEMPORARY table by using "CREATE TEMPORARY TABLE tmp_table_name SELECT ...". Because temporary table is thread safe.
proc2 declare the cursor on the tmp table which is created by proc1. Since the tmp table is already known and hard coded into the declaration, no more "table not found" error.
proc3 works like a "main" function, with all the parameters need to be sent to proc1 and proc2. proc3 simply calls proc1 first and then proc2 with the parameters need by each proc.
p.s Need to set system variable "sql_notes" to 0, otherwise proc1 will stop on DROP TABLE command.
Here is my example:
CREATE PROCEDURE `proc1`(SourceDBName CHAR(50), SourceTableName CHAR(50))
BEGIN
DECLARE SQLStmt TEXT;
SET #SQLStmt = CONCAT('DROP TEMPORARY TABLE IF EXISTS tmp_table_name');
PREPARE Stmt FROM #SQLStmt;
EXECUTE Stmt;
DEALLOCATE PREPARE Stmt;
SET #SQLStmt = CONCAT('CREATE TEMPORARY TABLE tmp_table_name SELECT ... FROM ',SourceDBName,'.',SourceTableName,' WHERE ... ');
PREPARE Stmt FROM #SQLStmt;
EXECUTE Stmt;
DEALLOCATE PREPARE Stmt;
END$$
CREATE PROCEDURE `proc2`(TargetDBName CHAR(50), TargetTemplateTableName CHAR(50))
BEGIN
DECLARE done INT DEFAULT 0;
DECLARE FieldValue CHAR(50);
DECLARE CursorSegment CURSOR FOR SELECT ... FROM tmp_table_name;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
OPEN CursorSegment;
REPEAT
FETCH CursorSegment INTO FieldValue;
IF NOT done THEN
...
END IF;
UNTIL done END REPEAT;
CLOSE CursorSegment;
END$$
CREATE PROCEDURE `proc3`(SourceDBName CHAR(50), SourceTableName CHAR(50), TargetDBName CHAR(50), TargetTemplateTableName CHAR(50))
BEGIN
CALL proc1(SourceDBName, SourceTableName);
CALL proc2(TargetDBName, TargetTemplateTableName);
END$$
No, you can't do that in cursors.
Maybe just prepared statements may do the job? :
delimiter ;;
create procedure test(in dbName varchar(40))
begin
set #query := CONCAT("SELECT * FROM " , dbName, ".db;");
PREPARE s from #query;
EXECUTE s;
DEALLOCATE PREPARE s;
end;;
delimiter ;
call test("mysql");
Try to create (temporary) table using prepared statement in a different procedure.
SET #query = CONCAT("CREATE TABLE temp_table AS SELECT cdrs_id, called, calling FROM " ,dbName, ".cdrs WHERE lrn_checked = 'N' ");
...
And then select data from that table in your 'test' procedure.
The answer to this is that it cannot be done. You cannot use variables in the cursor declaration. I appreciate noonex's response. However, his solution does not allow me to walk through the results. It simply executes the query.
create procedure test(in dbName varchar(40))
READS SQL DATA <- this line returns will allow you to walk through the results
begin
...
$result = call test("mysql");