I have a stored procedure which uses temporary tables so that I can summarize the sales of all the products within a certain product category. When I tried to run the code it failed. I search on google and here on stackoverflow but couldn't find what I had done wrong. I'm using MySQL server 5.5 on Windows Server.
CREATE PROCEDURE `getStatistics`(IN `startDate` date,IN `endDate` date,IN `categoryName` varchar)
BEGIN
CREATE TEMPORARY TABLE procResult(productName VARCHAR, amount INT);
CREATE TEMPORARY TABLE tblProductID(SELECT ID, `name` FROM product WHERE categoryID = (SELECT ID FROM category WHERE `name` = categoryName));
DECLARE done_amt, done_PID INT DEFAULT FALSE;
DECLARE amount, productID INT DEFAULT 0;
DECLARE pidCursor CURSOR FOR SELECT ID, `name` FROM tblProductID;
DECLARE amtCursor CURSOR FOR SELECT orderlines.amount FROM orderlines WHERE orderlines.productID = productID;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done_amt = TRUE;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done_PID = TRUE;
OPEN pidCursor;
pid_loop:LOOP
DECLARE productName VARCHAR;
FETCH pidCursor INTO productID, productName;
IF done_PID THEN
LEAVE pid_LOOP;
END IF;
OPEN amtCursor;
amt_loop:LOOP
DECLARE tmpAmount INT DEFAULT 0;
FETCH amtCursor INTO tmpAmount;
IF done_amt THEN
LEAVE amt_loop;
END IF;
amount = amount + tmpAmount;
END LOOP;
CLOSE amtCursor;
IF amount > 0 THEN
INSERT INTO procResult VALUES (productName, amount);
amount = 0;
END IF;
END LOOP;
CLOSE pidCursor;
END;
You must define the length of VARCHAR type variables, such as the categoryName parameter to your stored procedure;
You must DECLARE all local variables at the very start of a BEGIN ... END compound statement block, before any other commands;
Your syntax for CREATE TABLE ... SELECT is incorrect;
You have declared two handlers for the same SQL condition, only one of which will be executed (indeterminately);
You will need to change your client's statement delimiter in order for it to understand that the semicolons appearing within the procedure body do not terminate the CREATE PROCEDURE statement;
Your entire procedure is an extremely complicated way of doing a fairly simple task in SQL:
CREATE TEMPORARY TABLE procResult
SELECT product.name, SUM(orderlines.amount) AS amount
FROM orderlines
JOIN product ON product.ID = orderlines.productID
JOIN category ON category.ID = product.categoryID
WHERE category.name = ?
GROUP BY product.ID
HAVING amount > 0
Related
I have two (2) databases of dissimilar Schematics,
db1 migrated from MSSQL to MYSQL
and
db2 created from Laravel Migration.
Here's the challenge:
The tables of db1 do not have id columns (Primary Key) like is easily found on db2 tables. So I kept getting the warning message:
Current selection does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available.
So I had to inject the id columns on the tables in the db1
I need to extract fields [level_name, class_name] from stdlist in db1,
Create levels (id,level_name,X,Y) on db2
classes (id,class_name,level_id) on db2
To throw more light: The level_id should come from the already created levels table
I have already succeeded in extracting the first instance using the following snippet:
First Query to Create Levels
INSERT INTO db2.levels(level_name,X,Y)
SELECT class_name as level_name,1 as X,ClassAdmitted as Y
FROM db1.stdlist
GROUP BY ClassAdmitted;
This was successful.
Now, I need to use the newly created ids in levels table to fill up level_id column in the classes table.
For that to be possible, must I re-run the above selection schematics? Is there no better way to maybe join the table column from db1.levels to db2.stdlist and extract the required fields for the new insert schematics.
I'll appreciate any help. Thanks in advance.
Try adding a column for Processed and then do a while exists loop
INSERT INTO db2.levels(level_name,X,Y)
SELECT class_name as level_name,1 as X,ClassAdmitted as Y, 0 as Processed
FROM db1.stdlist
GROUP BY ClassAdmitted;
WHILE EXISTS(SELECT * FROM db2.levels WHERE Processed = 0)
BEGIN
DECLARE #level_name AS VARCHAR(MAX)
SELECT TOP 1 #level_name=level_name FROM db2.levels WHERE Processed = 0
--YOUR CODE
UPDATE db2.levels SET Processed=1 WHERE level_name=#level_name
END
You may need to dump into a temp table first and then insert into your real table (db2.levels) when you're done processing. Then you wouldn't need the Unnecessary column of processed on the final table.
This is what worked for me eventually:
First, I picked up the levels from the initial database thus:
INSERT INTO db2.levels(`name`,`school_id`,`short_code`)
SELECT name ,school_id,short_code
FROM db1.levels
GROUP BY name
ORDER BY CAST(IF(REPLACE(name,' ','')='','0',REPLACE(name,' ','')) AS UNSIGNED
INTEGER) ASC;
Then I created a PROCEDURE for the classes insertion
CREATE PROCEDURE dowhileClasses()
BEGIN
SET #Level = 1;
SET #Max = SELECT count(`id`) FROM db2.levels;
START TRANSACTION;
WHILE #Level <= #Max DO
BEGIN
DECLARE val1 VARCHAR(255) DEFAULT NULL;
DECLARE val2 VARCHAR(255) DEFAULT NULL;
DECLARE bDone TINYINT DEFAULT 0;
DECLARE curs CURSOR FOR
SELECT trim(`Class1`)
FROM db1.dbo_tblstudent
WHERE CAST(IF(REPLACE(name,' ','')='','0',REPLACE(name,' ','')) AS UNSIGNED INTEGER) =#Level
GROUP BY `Class1`;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET bDone = 1;
OPEN curs;
SET bDone = 0;
REPEAT
FETCH curs INTO val1;
IF bDone = 0 THEN
SET #classname = val1;
SET #levelID = (SELECT id FROM db2.levels WHERE short_code=#Level limit 1);
SET #schoolId = 1;
SET #classId = (SELECT `id` FROM db2.classes where class_name = #classname and level_id= #levelID limit 1);
IF #classId is null and #classname is not null THEN
INSERT INTO db2.classes(class_name,school_id,level_id)
VALUES(#classname,#schoolId,#levelID);
END IF;
END IF;
UNTIL bDone END REPEAT;
CLOSE curs;
END;
SELECT CONCAT('lEVEL: ',#Level,' Done');
SET #Level = #Level + 1;
END WHILE;
END;
//
delimiter ;
CALL dowhileClasses();
With this, I was able to dump The classes profile matching the previously created level_ids.
The whole magic relies on the CURSOR protocol.
For further details here is one of the documentations I used.
I have the following stored procedure in MySQL
CREATE DEFINER=`test_db`#`%` PROCEDURE `ADD_ATTENDANCE`(IN `programID` INT, IN `clientID` INT, IN `insDate` DATETIME, IN `updDate` DATETIME, IN `insUser` INT, IN `updUser` INT, IN `lessonDate` DATE, IN `lessonTime` TIME)
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT 'Add attedance to my calendar'
BEGIN
DECLARE max_sub, availability INT;
DECLARE cursor_max_sub CURSOR FOR SELECT max_sub FROM app_lesson WHERE id = programID;
DECLARE cursor_availability CURSOR FOR SELECT count(*) FROM attendance WHERE program_id = programID AND lesson_date = lessonDate AND lesson_time = lessonTime;
OPEN cursor_max_sub;
OPEN cursor_availability;
read_loop: LOOP
FETCH cursor_max_sub INTO max_sub;
FETCH cursor_availability INTO availability;
IF (availability < max_sub) THEN
insert into attendance (program_id, client_id, ins_date, upd_date, ins_user, upd_user, lesson_date, lesson_time)
values (programID, clientID, insDate, updDate, insUser, updUser, lessonDate, lessonTime);
LEAVE read_loop;
ELSE
insert into attendance_hold (program_id, client_id, ins_date, upd_date, ins_user, upd_user, lesson_date, lesson_time)
values (programID, clientID, insDate, updDate, insUser, updUser, lessonDate, lessonTime);
END IF;
END LOOP;
CLOSE cursor_max_sub;
CLOSE cursor_availability;
END;
Even though the cursor_max_sub is equal to 6 and the cursor_availability is equal to 4 my procedure always executes the else insert statement. Can you please help me out?
Thanks!!!
OK that was tricky... For some reason when i change the max_sub variable into maxNumberOfSubscription everything worked perfectly... Is max_sub some kind of reserved key word for MySQL or there was a complication because my variable had the same name with the returned field of select statement?
DELIMITER $$
CREATE PROCEDURE Load_Fact_List()
BEGIN
DECLARE Project_Number_Temp INT;
DECLARE Panel_Id_Temp INT;
DECLARE Employee_Id_Temp INT;
DECLARE Zip_Temp VARCHAR(255);
DECLARE Created_Date_Temp DATE;
DECLARE Country_Temp VARCHAR(255);
DECLARE no_more_rows BOOLEAN;
DECLARE loop_cntr INT DEFAULT 0;
DECLARE num_rows INT DEFAULT 0;
DECLARE load_cur CURSOR FOR
SELECT Project_Id, Panel_Id, Employee_Id, Zip, Created_Date
FROM Fact_List;
DECLARE CONTINUE HANDLER FOR NOT FOUND
SET no_more_rows = TRUE;
OPEN load_cur;
select FOUND_ROWS() into num_rows;
the_loop: LOOP
FETCH load_cur
INTO Project_Number_Temp, Panel_Id_Temp, Employee_Id_Temp, Zip_Temp, Created_Date_Temp;
IF no_more_rows THEN
CLOSE load_cur;
LEAVE the_loop;
END IF;
SET Country_Temp= (select Country from Zip where Zip= Zip_Temp);
INSERT INTO Test_Fact
(
Project_Key,
Campaign_Key,
Respondents_Key,
Event_Key,
Employee_Key,
Geography_Key,
Date_Key
)
SELECT (SELECT Project_Key from Project_Dim where Project_Id= Project_Number_Temp AND Quota_Country= Country_Temp),0,(SELECT MAX(Respondents_Key) from Respondents_Dim WHERE Panel_Id= Panel_Id_Temp),1,(select MAX(Employee_Key) from Employee_Dim WHERE Employee_Id= Employee_Id_Temp),(Select Geography_Key from Geography_Dim where Zip= Zip_Temp), (Select Date_Key from Date_Dim where Full_Date= Created_Date_Temp);
SET loop_cntr = loop_cntr + 1;
END LOOP the_loop;
select num_rows, loop_cntr;
END $$
The above code is properly working but it is damn slow. For every 1 hour it is loading 1000 records. I got lacks of records to load into fact table. can anyone suggest me any optimization?
Requirement is to load fact table by looping through other table and gathering required key values from dimension tables.
The usual procedure is actually like this.
You have your dimensions built and you just gathered the data you want to insert into your fact table in a temporary table. Then you insert this data in another temporary table like this:
INSERT INTO tmp_fact_table
(
fact_key,
dim1_key,
dim2_key,
...
fact1,
fact2
...
)
SELECT
ISNULL (f.fact_key, 0),
ISNULL (d1.sid, 0) as whatever,
ISNULL (d2.sid, 0) as whatever2,
...
ISNULL (tt.fact1, 0),
ISNULL (tt.fact2, 0)
FROM
yourTempTable tt
LEFT JOIN Dim1 d1 ON tt.identifying_column = d1.identifying_column
...
LEFT JOIN fact_table f ON
f.dim1_key = d1.sid
AND f.dim2_key = d2.sid
where
fact_key is the identifying column in your fact table
dim1_key is the foreign key in your fact table to the dimensions
fact1 and so on are the facts you want in your fact table, clear
the ISNULL() function returns 0 when no entry is found. 0 is the id of your dummy row in each dimension for unknown data
Then you will have a table where you have the IDs of your dimensions linked to the data you want to import into your fact table with 0 as fact key when the entry in the fact table does not already exist and the ID of the fact table entry otherwise.
Then you update the fact table where tmp_fact_table.fact_key != 0
Then you insert into the fact table where tmp_fact_table.fact_key = 0
That's it.
I'm doing this with millions of rows and it takes about half an hour. 300,000 rows is peanuts.
I've been Googleing around for a while and I am sure that the problem is that I don't understand clearly how CURSORs in MySQL work.
A short explanation of the problem: I'm writing such function (simplified):
CREATE DEFINER=`me`#`localhost` FUNCTION `product_move`(prID INT, tr_type VARCHAR(2), clID INT, am INT, dnID INT, usrID INT, price FLOAT(10,2), ti DATETIME, barc TINYTEXT, cmt TINYTEXT, lnID INT)
BEGIN
DECLARE done INT DEFAULT FALSE;
DECLARE cur_id INT;
DECLARE net_pr FLOAT(10,2);
DECLARE cur_r INT;
DECLARE remaind INT DEFAULT 0;
DECLARE avg_price FLOAT(10,2) DEFAULT 0;
DECLARE curs CURSOR FOR SELECT `products_transactionsID`,
`price`,
`remains`
FROM `products_transactions`
WHERE `productID`=prID AND `remains`>0 AND `type`='V'
ORDER BY `products_transactionsID` ASC;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
OPEN curs;
SET remaind=am;
read_loop:LOOP
FETCH curs INTO cur_id,net_pr,cur_r;
IF done THEN
LEAVE read_loop;
END IF;
IF (cur_r>=remaind) THEN
SET avg_price = avg_price + (net_pr * remaind);
UPDATE `products_transactions` SET `remains`=`remains`-remaind WHERE products_transactionsID=cur_id;
LEAVE read_loop;
ELSE
SET avg_price = avg_price + (net_pr * cur_r);
SET remaind=remaind-cur_r;
UPDATE `products_transactions` SET `remains`=0 WHERE products_transactionsID=cur_id;
END IF;
END LOOP;
CLOSE curs;
SET avg_price=avg_price/am;
INSERT INTO products_transactions
(`products_transactionsID`,`clientID`,`date_created`,`delivery_notesID`,`type`,`productID`,`amountIN`,`amountOUT`,`barcodes`,`in_stock`,`out_stock`,`out_repair`,`out_loss`,`booked`,`ordered`,`userID`,`price`,`comments`,`fifo_buy_price`)
SELECT NULL, clID, ti, dnID , tr_type, prID, 0, am, barc, products_transactions.in_stock-am, products_transactions.out_stock,
products_transactions.out_repair, products_transactions.out_loss, products_transactions.booked, products_transactions.ordered,usrID,price,cmt,avg_price
FROM
products_transactions WHERE productID=prID ORDER BY products_transactionsID DESC LIMIT 1;
So, we insert a new row in this table, based upon some calculations from the previously selected rows and updating these rows meanwhile.
The problem is with the avg_price variable, which should be calculated based on the net_pr variable which is FETCH'ed from the cursor. But somehow, instead of being FETCH'ed from the SELECT, the net_pr variable takes the value of the price input parameter of my function! How is that possible?
My guesses have been so far:
a variable name conflict? Searched through the code but I can't find any.
updating the table within the LOOP could make the CURSOR loose its position? It would make sense, but that wouldn't result in this, either...
I'd apreciate any ideas.
Two things that I can see:
1) Don't update the table that you're using in the cursor. MySQL says the cursor is read only but I wouldn't trust this. Set your value, exit the cursor, and then update the table.
2) Using the same name for a variable in the proc definition and a column in a select gives a conflict: http://dev.mysql.com/doc/refman/5.0/en/local-variable-scope.html
"A local variable should not have the same name as a table column. If an SQL statement, such as a SELECT ... INTO statement, contains a reference to a column and a declared local variable with the same name, MySQL currently interprets the reference as the name of a variable. "
In MySQL, I am converting a table from a single row per item type (a quantity of items) to a single row per item, so that additional detail can be stored about individual items.
Here is an example source table:
id parent_id qty item_type
-- --------- --- ---------
1 10291 2 widget
2 10292 4 thinger
I want to create a new table with a new column containing info that cannot be applied to more than one item. Thus, the above table would end up as follows:
id parent_id item_type info
-- --------- --------- ----
1 10291 widget [NULL]
2 10291 widget [NULL]
3 10292 thinger [NULL]
4 10292 thinger [NULL]
5 10292 thinger [NULL]
6 10292 thinger [NULL]
Is there a way I can iterate or loop each row of the source table, inserting a number of records equal to the source qty column? I would prefer to do this in sql instead of code to keep all of the conversion steps together (there are many others).
You can do with stored procedure. That will be like below. Below is stored procedure I am using for inserting products into log based on their quantity.
Seem you have to do similar task. You can get how to use database cursor in stored procedure to loop over a result set in MySQL from below example.
DELIMITER $$
DROP PROCEDURE IF EXISTS CursorProc$$
CREATE PROCEDURE CursorProc()
BEGIN
DECLARE no_more_products, quantity_in_stock INT DEFAULT 0;
DECLARE prd_code VARCHAR(255);
DECLARE cur_product CURSOR FOR
SELECT productCode FROM products;
DECLARE CONTINUE HANDLER FOR NOT FOUND
SET no_more_products = 1;
/* for loggging information */
CREATE TABLE infologs (
Id int(11) NOT NULL AUTO_INCREMENT,
Msg varchar(255) NOT NULL,
PRIMARY KEY (Id)
);
OPEN cur_product;
FETCH cur_product INTO prd_code;
REPEAT
SELECT quantityInStock INTO quantity_in_stock
FROM products
WHERE productCode = prd_code;
IF quantity_in_stock < 100 THEN
INSERT INTO infologs(msg)
VALUES (prd_code);
END IF;
FETCH cur_product INTO prd_code;
UNTIL no_more_products = 1
END REPEAT;
CLOSE cur_product;
SELECT * FROM infologs;
DROP TABLE infologs;
END$$
DELIMITER;
Seems your task is 90% same as above procedure. Just do needful changes. It will work.
I think you can create stored procedure, declare a cursor that reads source table and for each row inserts qty rows into destination table.
Based on other answers which provided some insight, I was able to find additional information (by Kevin Bedell) to create a stored procedure and use a cursor in a loop. I have simplified my solution so that it matches the example in my question:
DROP PROCEDURE IF EXISTS proc_item_import;
DELIMITER $$
CREATE PROCEDURE proc_item_import()
BEGIN
# Declare variables to read records from the cursor
DECLARE parent_id_val INT(10) UNSIGNED;
DECLARE item_type_val INT(10) UNSIGNED;
DECLARE quantity_val INT(3);
# Declare variables for cursor and loop control
DECLARE no_more_rows BOOLEAN;
DECLARE item_qty INT DEFAULT 0;
# Declare the cursor
DECLARE item_cur CURSOR FOR
SELECT
i.parent_id, i.qty, i.item_type
FROM items i;
# Declare handlers for exceptions
DECLARE CONTINUE HANDLER FOR NOT FOUND
SET no_more_rows = TRUE;
# Open the cursor and loop through results
OPEN item_cur;
input_loop: LOOP
FETCH item_cur
INTO parent_id_val, item_type_val, quantity_val;
# Break out of the loop if there were no records or all have been processed
IF no_more_rows THEN
CLOSE item_cur;
LEAVE input_loop;
END IF;
SET item_qty = 0;
qty_loop: LOOP
INSERT INTO items_new
(parent_id, item_type)
SELECT
parent_id_val, item_type_val;
SET item_qty = item_qty + 1;
IF item_qty >= quantity_val THEN
LEAVE qty_loop;
END IF;
END LOOP qty_loop;
END LOOP input_loop;
END$$
DELIMITER ;
Before asking this question, I had not used a stored procedures, cursors, or loops. That said, I have read and encountered them frequently on SE and elsewhere, and this was a good opportunity to learn
It may be worth noting that the example on Kevin's page (linked above) does not use END%% (just END) which caused some headache in trying to get the script to work. When creating a procedure, it is necessary to change the delimiter temporarily so that semicolons terminate statements inside the procedure, but not the creation process of the procedure itself.
That is just an example of code that I have here, it is not adapted to your needs, but it does exactly what you need, and it is simple than a procedure, or temporary table.
SELECT event, id, order_ref, storeitem_barcode_create(8), NOW()
FROM (
SELECT mss.id, mss.event, mss.order_ref, mss.quantity, mss.product_id,
#rowID := IF(#lastProductID = mss.product_id AND #lastID = mss.id, #rowID + 1, 0) AS rowID,
#lastProductID := mss.product_id,
#lastID := mss.id
FROM module_barcode_generator mbg,
(SELECT #rowID := 0, #lastProductID := 0, #lastID := 0) t
INNER JOIN module_events_store_sold mss ON mss.order_ref = "L18T2P"
) tbl
WHERE rowId < quantity;
Typo in JYelton's solution for his/her own question:
FETCH item_cur
INTO parent_id_val, item_type_val, quantity_val;
Should be:
FETCH item_cur
INTO parent_id_val, quantity_val, item_type_val;
Otherwise very good.