Update and Select in One Query

Update and select in one query

UPDATE tblPopUp  
SET PopUp = 'False', Period = Period  
OUTPUT DELETED.Period
WHERE DisplayNo = 1

For more information about OUTPUT clause please check this post.

How do I UPDATE from a SELECT in SQL Server?

UPDATE
    Table_A
SET
    Table_A.col1 = Table_B.col1,
    Table_A.col2 = Table_B.col2
FROM
    Some_Table AS Table_A
    INNER JOIN Other_Table AS Table_B
        ON Table_A.id = Table_B.id
WHERE
    Table_A.col3 = 'cool'

Is there a way to SELECT and UPDATE rows at the same time?

Consider looking at the OUTPUT clause:

USE AdventureWorks2012;  
GO  

DECLARE @MyTableVar table(  
    EmpID int NOT NULL,  
    OldVacationHours int,  
    NewVacationHours int,  
    ModifiedDate datetime);  

UPDATE TOP (10) HumanResources.Employee  
SET VacationHours = VacationHours * 1.25,  
    ModifiedDate = GETDATE()   
OUTPUT inserted.BusinessEntityID,  
       deleted.VacationHours,  
       inserted.VacationHours,  
       inserted.ModifiedDate  
INTO @MyTableVar;  

--Display the result set of the table variable.  
SELECT EmpID, OldVacationHours, NewVacationHours, ModifiedDate  
FROM @MyTableVar;  
GO  
--Display the result set of the table.  
SELECT TOP (10) BusinessEntityID, VacationHours, ModifiedDate  
FROM HumanResources.Employee;  
GO 

Mysql: First Select then Update in One Query

The operation you describe, returning a resultset from a SELECT and performing an UPDATE cannot be performed in a single SQL statement in MySQL.

You would need two separate SQL statements: a SELECT and an UPDATE.

In terms of MySQL, it is not necessary to run a SELECT before running an UPDATE, it's possible to run just an UPDATE.

UPDATE `messages` SET somecol = 'somevalue' WHERE `timestamp`>'1422680952'

(The query in the question is enclosed in double quotes. That leads us to suspect that you are running this statement from a database interface library in a language such as PHP.)

It is possible to get multiple statements to execute as part of a single transaction. But as far as how the MySQL server itself is actually processing the specified operations, that's going to be two separate statements.

How to select and update in one query?

Resolve this!

DECLARE @id int;
SET @id = (select top(1) id from [table] where [x] = 0 order by id desc);

select * from [table] where id = @id;
update [table] set [x] = 20 where id = @id;

:D

SQL - Update multiple records in one query

Try either multi-table update syntax

UPDATE config t1 JOIN config t2
    ON t1.config_name = 'name1' AND t2.config_name = 'name2'
   SET t1.config_value = 'value',
       t2.config_value = 'value2';

Here is a SQLFiddle demo

or conditional update

UPDATE config
   SET config_value = CASE config_name 
                      WHEN 'name1' THEN 'value' 
                      WHEN 'name2' THEN 'value2' 
                      ELSE config_value
                      END
 WHERE config_name IN('name1', 'name2');

Here is a SQLFiddle demo

MySQL - UPDATE query based on SELECT Query

You can actually do this one of two ways:

MySQL update join syntax:

UPDATE tableA a
INNER JOIN tableB b ON a.name_a = b.name_b
SET validation_check = if(start_dts > end_dts, 'VALID', '')
-- where clause can go here

ANSI SQL syntax:

UPDATE tableA SET validation_check = 
    (SELECT if(start_DTS > end_DTS, 'VALID', '') AS validation_check
        FROM tableA
        INNER JOIN tableB ON name_A = name_B
        WHERE id_A = tableA.id_A)

Pick whichever one seems most natural to you.

SELECT, UPDATE, DELETE with one SQL query?

Short answer is that it's not possible without wrapping the extra queries inside a trigger or procedure.

You can do this in a transaction, and without a SELECT, but it will take 3 queries:

START TRANSACTION;

    UPDATE cart_items 
       SET quantity = quantity - 1
     WHERE cart_id = {$cart_id} 
       AND id = {$cart_item_id};

    DELETE 
      FROM cart_items
     WHERE quantity = 0
       AND cart_id = {$cart_id} 
       AND id = {$cart_item_id};

    DELETE c
      FROM cart c
 LEFT JOIN cart_items ci
        ON ci.cart_id = c.id
     WHERE c.id = {$cart_id}
       AND ci.cart_id IS NULL;

COMMIT;

The last DELETE joins cart to cart_items, and deletes the cart if none are found (cart_items fields are NULL).

I have included available identifiers to speed up the DELETEs, although they should be fine without them.. it'll just look for and pick up any other quantity 0 items or empty carts.

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