CODEWITHSUNDEEP
sqlsql-server
danglesauce19
danglesauce19

Reputation: 133

Join of Two Tables where Data Matches in One Column

For some reason I have a hard time grasping joins and this one should be very simple with the knowledge that I have in SQL.

Anyway, I have 2 tables. We will call them TableA and TableB. One of the columns in TableA is "ID". TableB only consists of the column "ID". I want to return all rows in TableA whose ID is present in TableB.

I know this should be very simple to figure out, but my brain doesn't want to work today.

Upvotes: 0

Views: 64

Answers (3)

irakliG.
irakliG.

Reputation: 176

You can also use IN operator like this: 

Select  *
From    TableA 
Where   ID in
(
    Select distinct ID
    From    TableB
)

Upvotes: 1

user5993035
user5993035

Reputation:

this should work

 SELECT B.ID 
 FROM TableA A 
 JOIN TableB B 
 ON (A.ID=B.ID)
 WHERE A.ID=B.ID

Upvotes: 2

Siyual
Siyual

Reputation: 16917

You can do this using an EXISTS:

Select  A.*
From    TableA  A
Where   Exists
(
    Select  *
    From    TableB  B
    Where   A.Id = B.Id
)

You can also use a JOIN if you wish, but depending on your data, you may want to couple that with a SELECT DISTINCT:

Select  Distinct A.*
From    TableA  A
Join    TableB  B   On  A.Id = B.Id

One thing to keep in mind is that the ID of TableA is not necessarily related to the ID of TableB.

Upvotes: 3

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