I'm doing an sql query on two tables in a database. I want to select data from table one only if the data in columns one and columns two on both tables match. Please help.. Tables one and two have the same structure.
2 Answers
That sounds like a job for EXISTS() which will check if a record with the same (column1,column2) exists.
SELECT * FROM Table1 t
WHERE EXISTS(SELECT 1 FROM Table2 s
WHERE t.column1 = s.column1 and t.column2 = s.column2)
Can also be done with an INNER JOIN :
SELECT t.* FROM Table1 t
INNER JOIN Table2 s
ON(t.column1 = s.column1 and t.column2 = s.column2)
3 Comments
CodeAndTheory
Hello sabi, thanks for the answer. From your sql above, what does the variable "t" mean..? I'm lost there.
sagi
@CodeAndTheory An alias, not variable, instead of writing table1.ColName every time I call table1
t and then I can use t.CodeAndTheory
Thanks for clarification. I can't upvote for now since my reputation is low. But it's looking like exactly what I need. Will sure visit this in future. Thanks again.
I would use INNER JOIN:
SELECT column_name(s)
FROM table1
INNER JOIN table2
ON table1.column_name=table2.column_name
Hope this helps you :)
1 Comment
CodeAndTheory
Amazing. This one also worked. Thank you Akimbo.
JOINis perhaps what you are looking for. Sample table data, and the expected result may however make me change my mind.