I just started working with SQL and have been working with MySQL.I am trying to write a stored procedure that will take each value from my buyPrice column in my products table, and store each value into a variable. I then want it to multiply this variable by the sales tax and then take each result and place it into my empty sales_tax column. I would like to populate the whole column with the sales tax for each item. When I execute this method I get some error saying the productCode doesn't have a default value. What is the proper way to write this? I know this isn't the most efficient way of doing this task, just trying to practice.
DELIMITER //
CREATE PROCEDURE nFirstProcedure()
BEGIN
DECLARE IdValue, counter, holdValue, result INT DEFAULT 0;
DECLARE holdName VARCHAR(30);
SET counter = 1;
WHILE counter < ( SELECT COUNT(*) FROM products)
DO
SET holdValue = (SELECT buyPrice FROM products WHERE sales_tax = null);
SET result = (holdValue * 0.08);
INSERT INTO products (sales_tax) VALUES (result);
END WHILE;
END//
DELIMITER ;
You should not do this with a loop. Just use update:
update products
set sales_tax = buyPrice * 0.08
where sales_tax is null;
Related
I searched a lot of doing a task but found no appropriate solution.
Basically the scenario is. I have a user_comment table in which there are 5 column(id,parent_id,user_comments,is_deleted,modified_datetime). There is a parent child relationship like 1->2,1->3,2->4,2->5,5->7 etc. Now i am sending the id from the front end and i want to update the column is_deleted to 1 and modified_datetime on all the records on
this id as well as the all the children and children's of children.
I am trying to doing this by using a recursive procedure. Below is the code of my procedure
CREATE DEFINER=`root`#`localhost` PROCEDURE `user_comments`(
IN mode varchar(45),
IN comment_id int,
)
BEGIN
DECLARE p_id INT DEFAULT NULL ;
if(mode = 'delete')
then
update user_comment set is_deleted = 1, modified_datetime = now()
where id = comment_id ;
select id from user_comment where parent_id = comment_id into p_id ;
if p_id is not null
then
SET ##GLOBAL.max_sp_recursion_depth = 255;
SET ##session.max_sp_recursion_depth = 255;
call user_comments('delete', p_id);
end if;
end if;
END
By using this procedure it give me an error of more than one row.
If i return the select query without giving it to variable then shows me the the appropriate results on the select query but i have to call this procedure recursively based on getting the ids of the select query.
I need help i have already passed 2 days into this.
I used cursor also. Below is the code of cursor
CREATE DEFINER=`root`#`localhost` PROCEDURE `user_comments`(
IN mode varchar(45),
IN comment_id int,
)
BEGIN
DECLARE p_emp int;
DECLARE noMoreRow INT;
DECLARE cur_emp CURSOR FOR select id from user_comment where parent_id = comment_id ;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET noMoreRow = 0;
if(mode = 'delete')
then
OPEN cur_emp;
LOOPROWS: LOOP
IF noMoreRow = 0 THEN
update user_comment set is_deleted = 1, modified_datetime = now() where id = comment_id
CLOSE cur_emp;
LEAVE LOOPROWS;
END IF;
FETCH cur_emp INTO p_emp;
update user_comment set is_deleted = 1, modified_datetime = now() where id = p_emp ;
SET ##GLOBAL.max_sp_recursion_depth = 255;
SET ##session.max_sp_recursion_depth = 255;
call user_comments('delete', p_emp);
END LOOP;
end if;
END
After using cursor i am getting a thread error.i don't know how can overcome this problem!!!
Mysql's documentation on select ... into varlist clearly says:
The selected values are assigned to the variables. The number of
variables must match the number of columns. The query should return a
single row. If the query returns no rows, a warning with error code
1329 occurs (No data), and the variable values remain unchanged. If
the query returns multiple rows, error 1172 occurs (Result consisted
of more than one row). If it is possible that the statement may
retrieve multiple rows, you can use LIMIT 1 to limit the result set to
a single row.
Since you wrote in the OP that a comment can be parent of many comments, using simple variables cannot be a solution. You should use a CURSOR instead, that can store an entire resultset.
You loop through the records within the cursos as shown in the sample code in the above link and call user_comments() in a recursive way.
UPDATE
If your receive
Error Code: 1436. Thread stack overrun
error, then you can do 2 things:
Increase the thread_stack setting in the config file and restart mysql server.
You can try to simplify your code to use less recursions and therefore less stack space. For example, when you fetch all children into the cursor, then rather calling the user_comments() recursively for each, you can set all direct children's status within the code and call the function recirsively on grand-childrens only (if any). You can also change your data structure and use nested set model to approach hierarchical structures.
Nested set model is more complex to understand, it is less resource intensive to traverse, but more resource intensive to maintain.
I have 100 rows in table tbl_master_sales and an empty table tbl_customer_sales.When I use WHILE loop to insert data from tbl_master_salesto tbl_customer_sales,it only inserts 50 rows.However,it should have insert 100 rows taking two iteration of while loop.What may be my mistake in following PROCEDURE:
CREATE PROCEDURE ROWPERROW()
BEGIN
DECLARE n INT DEFAULT 0;
DECLARE i INT DEFAULT 0;
SELECT COUNT(*) FROM tbl_master_sales INTO n;
SET i=0;
WHILE i<n DO
INSERT INTO tbl_customer_sales (id,card_number,customer_name,customer_phone,bill_no,item_code,division,section,department,item_name,store,promo_name,billdiscount_name,billqty,promo_amount,bill_discount_amount,loyaltyamount,net_amount)
SELECT id, card_number, customer_name, customer_mobile, billno, itemcode, division, section, department, itemname, store, promoname, billdiscountname, billqty, promoamount, billdiscountamount, loyaltyamount, netamount
FROM tbl_master_sales
WHERE NOT EXISTS(SELECT 1
FROM tbl_customer_sales
WHERE id=tbl_master_sales.id)
LIMIT i,50;
SET i = i + 50;
END WHILE;
End;;
I don't see anything wrong with your procedure code logic but the reason for inserting only 50 rows could be the NOT EXISTS part shown below, which is restricting from inserting duplicate rows (or) filtering out the rest records.
WHERE NOT EXISTS(
SELECT 1
FROM tbl_customer_sales
WHERE id=tbl_master_sales.id)
Is it possible to use a GROUP_CONCAT in a SELECT as the input of a MySQL function? I cannot figure out how to cast the variable it seems. I've tried blob. I've tried text (then using another function to break it up into a result set, here) but I haven't had any success.
I want to use it like this:
SELECT
newCustomerCount(GROUP_CONCAT(DISTINCT items.invoicenumber)) AS new_customers
FROM items;
Here is the function:
DROP FUNCTION IF EXISTS newCustomerCount;
DELIMITER $$
CREATE FUNCTION newCustomerCount(invoicenumbers BLOB)
RETURNS INT
DETERMINISTIC
BEGIN
DECLARE new_customers INT;
SET new_customers = 0;
SELECT
SUM(nc.record) INTO new_customers
FROM (
SELECT
1 AS customer,
(SELECT COUNT(*) FROM person_to_invoice ps2 WHERE person_id = ps1.person_id AND invoice < ps1.invoice) AS previous_invoices
FROM person_to_invoice ps1
WHERE invoice IN(invoicenumbers)
HAVING previous_invoices = 0
) nc;
RETURN new_customers;
END$$
DELIMITER ;
Because Mysql functions do not support dynamic queries, I recommend you re-think your basic strategy to pass in a list of invoice numbers to your function. Instead, you could modify your function to accept a single invoice number and return the number of new customers just for the one invoice number.
Also, there are some optimizations you can make in your query for finding the number of new customers.
DROP FUNCTION IF EXISTS newCustomerCount;
DELIMITER $$
CREATE FUNCTION newCustomerCount(p_invoice INT)
RETURNS INT
DETERMINISTIC
BEGIN
DECLARE new_customers INT;
SET new_customers = 0;
SELECT
COUNT(DISTINCT ps1.person_id) INTO new_customers
FROM
person_to_invoice ps1
WHERE
ps1.invoice = p_invoice
AND NOT EXISTS (
SELECT 1
FROM person_to_invoice ps2
WHERE ps1.person_id = ps2.person_id
AND ps2.invoice < ps1.invoice
);
RETURN new_customers;
END$$
DELIMITER ;
Then you can still get the total number of new customers for a given list of invoice numbers like this:
SELECT
SUM(newCustomerCount(invoice)) as total_new_customers
FROM items
WHERE ...
You could try FIND_IN_SET() instead of IN(). The performance will probably be horrible when passing in a long list of invoice numbers. But it should work.
WHERE FIND_IN_SET(invoice, invoicenumbers)
You are looking in the wrong place.
WHERE invoice IN(invoicenumbers) will not do the desired substitution. Instead you need to use CONCAT to construct the SQL, then prepare and execute it.
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
I have a stored procedure, shown below, which I created to add dollar sales to a table (WeeklySales) which currently stores only unit sales. The cursor operates on on the WeeklySales table. The pricing data is stored in the Pricing table. The Pricing table actually contains changes in prices. The effective date for a price change is stored in Pricing.effectiveDate, so I have to find the pricing which was effective for the week in which the unit was sold (which is stored in WeeklySales.weekStart).
The problem I'm having is that the first select after the IF doesn't return anything. I've confirmed that this select does return a value when I run it outside of the procedure using the values which it would be called with inside the procedure. I'm not sure what's wrong here, but I'm guessing maybe this has to do with the fact that the this select is operating on a table which is different from the cursor? Anyone know? Is there a better way to do this?
DELIMITER //
CREATE PROCEDURE `createWeeklyPricing` (IN startDate DATE, IN endDate DATE)
BEGIN
--
-- Populate the proceeds column using the Pricing table
DECLARE product VARCHAR(255);
DECLARE weekStart DATE;
DECLARE units, done INT;
DECLARE proceeds DECIMAL(6,2);
DECLARE effectiveDate DATE;
DECLARE currentRow CURSOR FOR SELECT `weekStart`, `product`, `units` FROM `WeeklySales` WHERE `weekStart` >= startDate AND `weekStart` <= endDate;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
OPEN currentRow;
SET done = 0;
WHILE done = 0 DO
FETCH currentRow INTO weekStart, product, units;
IF done = 0 THEN
SELECT MAX(`effectiveDate`) FROM `Pricing` WHERE `effectiveDate` <= weekStart AND `product` = product INTO effectiveDate;
SELECT `proceeds` FROM `Pricing` WHERE `effectiveDate` = effectiveDate AND `product` = product INTO proceeds;
UPDATE `WeeklySales` SET `proceeds` = units * proceeds WHERE `weekStart` = weekStart AND `product` = product;
END IF;
END WHILE;
CLOSE currentRow;
END//
echo (select) weekstart before the if statement...
If it returns null change the select FROM WeeklySales WHERE weekStart between startDate AND endDate
you need to use the INTO before FROM and variable needs '#' sign
change it to
SELECT MAX(`effectiveDate`) INTO #effectiveDate FROM `Pricing` WHERE `effectiveDate` <= weekStart AND `product` = product ;
hope this helps
This is because your variable name is overwriting your column name:
You have a variable named 'effectiveDate'
You have a column named 'effectiveDate'
SELECT MAX(`effectiveDate`) ...
Is MAX-ing the variable effectiveDate, not the column
Try naming the variable maxEffectiveDate
Beware that variables are case insensitive. This happened to me when i tried to select column IsBackUp into variable isBackUp (notice the i).