Solved Subtraction operation in query (1 Viewer)

Koloss1

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Hello,

I have a query in which I subtract values from two tables.

Table magacin_CLT_ulaz and magacin_CLT_izlaz

The first table is the entry of goods into the warehouse, the second is the exit of goods.
These are building elements and common values can be length, width, height. Of course, the quantity is different.
In the query I tried to subtract the quantities of goods that came in and the quantity of goods that came out.

SQL:
SELECT magacin_CLT_ulaz.kolicina AS A, magacin_CLT_izlaz.kolicina AS B, [A]-[B] AS Expr1
FROM magacin_CLT_ulaz INNER JOIN magacin_CLT_izlaz ON (magacin_CLT_ulaz.debljina = magacin_CLT_izlaz.debljina) AND (magacin_CLT_ulaz.sirina = magacin_CLT_izlaz.sirina) AND (magacin_CLT_ulaz.duzina = magacin_CLT_izlaz.duzina);

I get nothing as a result. Where am I wrong?
 

theDBguy

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Since your query does not have a WHERE Clause, if you didn't get any records back, it would mean non of the records match with the JOIN fields you used. If so, you might double-check the data.

Also, why do you have two separate tables storing the same thing? Just curious... A typical approach is to use one table where incoming is entered as a positive number and outgoing is entered as a negative number.
 

Koloss1

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The problem is that I would have to get a result because the entries match.
My answer is because of the stupidity.
It's logical what you said....
But how do I say "enter value as negative number"
 

theDBguy

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The problem is that I would have to get a result because the entries match.
My answer is because of the stupidity.
It's logical what you said....
But how do I say "enter value as negative number"
How are you entering the data now? You either manually (or automatically) assign a negative number or add a field to designate whether the record is "incoming" or "outgoing." You can then use that "category" field to perform your calculations/queries.
 

Koloss1

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How are you entering the data now? You either manually (or automatically) assign a negative number or add a field to designate whether the record is "incoming" or "outgoing." You can then use that "category" field to perform your calculations/queries.
Maybe i can use this:

Code:
Me!TextboxR = 0 - Me!TeaxtboxR
or
Code:
Me!TextboxR = Me!TextboxR * -1
after update event.

Data are entered via the form and the command button.
 

theDBguy

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Maybe i can use this:

Code:
Me!TextboxR = 0 - Me!TeaxtboxR
or
Code:
Me!TextboxR = Me!TextboxR * -1
after update event.

Data are entered via the form and the command button.
Right. Actually, I would recommend using the *-1.
 

jdraw

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You are welcome. Happy to help.
 

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