How do I change the value of data in table?

Question

1.00/5 (1 vote)

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everytime when i change aantal to 0 it changes back to 5 for some reason.
does someone know why?
i want to fill a number for aantal and then multiply it with "prijs".

bierid aantal  prijs
1	5	2
2	0	2
NULL	NULL	NULL

CREATE TABLE [dbo].[Bier] (
    [BierId]             INT IDENTITY (1, 1) NOT NULL,
    [Aantal_consumpties] INT NULL ,
    [Prijs]              INT NOT NULL,
    PRIMARY KEY CLUSTERED ([BierId] ASC)

What I have tried:

"select sum(Aantal_consumpties * Prijs) AS prijsbier FROM Bier";

Posted 5-Jan-18 3:48am

Member 13554627

Updated 5-Jan-18 7:24am

Leo Chapiro

v3

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2 solutions

Solution 2

You really need to spend some time here [click][^]. This is a rather friendly environment where you can learn-by-doing.

It's much easier, especially in the long run, to just learn how to do basic SQL queries.

Posted 5-Jan-18 7:24am

W∴ Balboos, GHB

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Leo Chapiro · Accepted Answer · 2018-01-05T03:59:00

Solution 1

You do not change the value by doing

SQL

select sum(Aantal_consumpties * Prijs) AS prijsbier FROM Bier

What you need is an UPDATE:

SQL

UPDATE Bier SET Aantal_consumpties = 5;
select sum(Aantal_consumpties * Prijs) AS prijsbier FROM Bier;

Posted 5-Jan-18 3:59am

Leo Chapiro

Comments

Leo Chapiro 5-Jan-18 11:10am

I can not solve all your problems, dude. The answer refers to your question about "how to change a value". If it helps, don't hesitate to mark it as accepted.

Maciej Los 7-Jan-18 7:30am

Short And To The Point!
5ed!

Leo Chapiro 8-Jan-18 5:20am

Thanks a lot, Maciej!