CODEWITHSUNDEEP
sqldatabaseoracle-database
Luke4792
Luke4792

Reputation: 455

Problems linking tables in oracle SQL

I have two tables, for simplicity let's call them table A and table B. Table A contains 2 rows of values, and table B contains 4 rows of values. Table A is linked to Table B through a foreign key constraint, linked to Table B's primary key. However, if I try to run a query selecting every row from both of these columns, for each row in Table A it runs through every row in table B, for example:

Is there a problem with my tables here? Or is it the case of a bad query?

Upvotes: 0

Views: 62

Answers (2)

Serge
Serge

Reputation: 626

select a.colA, a.colB, b.colA, b.colB, b.colC, b.coldD from TableA a, TableB b where a.colA=b.colA;

Assuming colA should be primary/foreign key in each of the tables.

Upvotes: 1

Bertrand Deroanne
Bertrand Deroanne

Reputation: 41

Try this :

(Change ColumnValue, NameOfForeignKey and PrimaryKey by the correct column name)

Solution 1 :

SELECT TableA.ColumnValue, TableB.ColumnValue
FROM TableA 
INNER JOIN TableB ON TableA.NameOfForeignKey = TableB.PrimaryKey

Solution 2 :

SELECT TableA.ColumnValue, TableB.ColumnValue
FROM TableA, TableB 
WHERE TableA.NameOfForeignKey = TableB.PrimaryKey

Upvotes: 0

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