Loop execute statement in Stored Procedure - mysql

I have the following sccenario:
CREATE DEFINER=`test`#`%` PROCEDURE `prTest`()
BEGIN
SET #prepared_sql = 'select field1, field2 from table_data1');
PREPARE stmt FROM #prepared_sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END
I have to open the "stmt" in a loop. How do I read this loop and each row, getting the values of "field1" and "field2" ​​and insert the values ​​in another table?


Resolved:
CREATE DEFINER=`test`#`%` PROCEDURE `prTest`()
BEGIN
SET #prepared_sql = 'insert into table_data2
select field1, field2 from table_data1');
PREPARE stmt FROM #prepared_sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END

Related

How Do I Use Dynamic SQL (MySQL) To Store The Result of a Query Into a Local Variable?

In the procedure I'm writing I need to store the result of a dynamic SQL query into a local variable. Something like this:
DELIMITER //
CREATE PROCEDURE test_maxsum(uid varchar(25))
BEGIN
DECLARE maxsum int;
SET #SQL = CONCAT('SELECT MAX(sum_val) FROM ', uid);
PREPARE stmt FROM #SQL;
EXECUTE stmt INTO maxsum;
DEALLOCATE PREPARE stmt;
SELECT maxsum;
END//
DELIMITER ;

Local variables cannot be assigned in prepared statements. You can use user-defined variables though:
DELIMITER //
CREATE PROCEDURE test_maxsum(uid varchar(25))
BEGIN
SET #SQL = CONCAT('SELECT MAX(sum_val) INTO #maxsum FROM ', uid);
PREPARE stmt FROM #SQL;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SELECT #maxsum;
END//
DELIMITER ;

Create a dynamic procedure call statement in mysql

if I want to call a procedure with different input in each time input1,input2, input 3, ... and different output out1,out2,...and so on
proc(input1,out1) proc(input2,out2)...
can I made only one prepared statement inside a while loop to do that job? something like this
while c <= 10 DO
SET #sql = CONCAT('call proc(input',c,',out',c')');
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
set c=c+1;
end while;

MySQL dynamic SQL procedure unknown syntax error

Having trouble with this stored procedure. Been at it for at least 4 hours, and still, no luck.
It creates the procedure no problem, but, when trying to call it, it throws a syntax error with no clues where to find the mistake. (Syntax error near '').
I'm using MySQL 5.6.39, and as client, HeidiSQL 9.5.0.5196
Edit: The purpose of this procedure, is to calculate the average time from another table, ignoring the outliers, that's why I used so many temp tables.
Thanks again!
Here's the code
DROP PROCEDURE IF EXISTS tiempoPromedioUsuarioP;
DELIMITER //
CREATE PROCEDURE tiempoPromedioUsuarioP (IN current_user_id INT, IN outliers FLOAT(4,3), OUT promedio_segundos INT)
BEGIN
DECLARE done INT DEFAULT FALSE;
SET #s1 = CONCAT('CREATE TEMPORARY TABLE tp',current_user_id, ' (SELECT TIMESTAMPDIFF(SECOND, sesion_log.init_date, sesion_log.end_date) AS tiempoPromedio FROM sesion_log WHERE sesion_log.id_usuario = ', current_user_id, ' AND sesion_log.is_end = 1;');
PREPARE stmt1 FROM #s1;
EXECUTE stmt1;
DEALLOCATE PREPARE stmt1;
SET #s2 = CONCAT('CREATE TEMPORARY TABLE boundsA',current_user_id,' (SELECT (AVG(tp',current_user_id,'.tiempoPromedio) - STD(tp',current_user_id,'.tiempoPromedio)*',outliers,') AS lb FROM tp',current_user_id,');');
PREPARE stmt2 FROM #s2;
EXECUTE stmt2;
DEALLOCATE PREPARE stmt2;
SET #s3 = CONCAT('CREATE TEMPORARY TABLE boundsB',current_user_id,' (SELECT (AVG(tp',current_user_id,'.tiempoPromedio) + STD(tp',current_user_id,'.tiempoPromedio)*',outliers,') AS ub FROM tp',current_user_id,');');
PREPARE stmt3 FROM #s3;
EXECUTE stmt3;
DEALLOCATE PREPARE stmt3;
SET #s4 = CONCAT('CREATE TEMPORARY TABLE res',current_user_id,' SELECT round(AVG(tp',current_user_id,'.tiempoPromedio)) as promedio FROM tp WHERE tp',current_user_id,'.tiempoPromedio BETWEEN (SELECT lb FROM boundsA',current_user_id,') AND (SELECT ub FROM boundsB',current_user_id,');');
PREPARE stmt4 FROM #s4;
EXECUTE stmt4;
DEALLOCATE PREPARE stmt4;
SET #s5 = CONCAT('
DECLARE promedioc CURSOR FOR SELECT * FROM res',current_user_id,';
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
OPEN promedioc;
read_loop: LOOP
FETCH promedioc INTO promedio_segundos;
IF done THEN
LEAVE read_loop;
END IF;
END LOOP;
CLOSE promedioc;
');
PREPARE stmt5 FROM #s5;
EXECUTE stmt5;
DEALLOCATE PREPARE stmt5;
SET #s6 = CONCAT('DROP TEMPORARY TABLE tp',current_user_id);
PREPARE stmt6 FROM #s6;
EXECUTE stmt6;
DEALLOCATE PREPARE stmt6;
SET #s7 = CONCAT('DROP TEMPORARY TABLE boundsA',current_user_id);
PREPARE stmt7 FROM #s7;
EXECUTE stmt7;
DEALLOCATE PREPARE stmt7;
SET #s8 = CONCAT('DROP TEMPORARY TABLE boundsB',current_user_id);
PREPARE stmt8 FROM #s8;
EXECUTE stmt8;
DEALLOCATE PREPARE stmt8;
SET #s9 = CONCAT('DROP TEMPORARY TABLE res',current_user_id);
PREPARE stmt9 FROM #s9;
EXECUTE stmt9;
DEALLOCATE PREPARE stmt9;
END//
DELIMITER ;
Thanks for your help!

mysql prepared statment giving error

i am trying to write a stored procedure which updates the field of a table as specified in the argument .i am getting syntax error in #sql statment.please help
create procedure new_upd1(ind int(3),attribute varchar(30),pk int(11),new_value varchar(30))
begin
set #att=attribute;
set #primk=pk;
set #updated=new_value;
if ind=1 then
set #sql='update department set ?=? where departmentid=?';
prepare stmt from #sql;
execute stmt using #att,#updated,#primk;
deallocate prepare stmt;
end if;
end

Parameters don't work for column or table names, only for values. Do it like this:
create procedure new_upd1(ind int(3),attribute varchar(30),pk int(11),new_value varchar(30))
begin
set #att=attribute;
set #primk=pk;
set #updated=new_value;
if ind=1 then
set #sql=CONCAT('update department set ', #att, '=? where departmentid=?;');
prepare stmt from #sql;
execute stmt using #updated,#primk;
deallocate prepare stmt;
end if;
end

Insert query on procedure

I have a procedure like this
set #dt=now();
SET #query = CONCAT('insert into tbl_Name (Name , Created_Date , Created_By) values (?,?,?)');
PREPARE stmt FROM #sql;
EXECUTE stmt using #tbl_column_value, #dt, #tbl_user_id;
END IF;
DEALLOCATE PREPARE stmt;
im getting this error
java.sql.SQLException: Incorrect arguments to EXECUTE