How to select just unique values into a mysql table based on the value in one column?
Question
I have table named x
Here is the sample data in table x
Column1_ _ __ _ __ _ __ _ _ Column2_ _ __ _ __ _ __ _ ___ Column3
a _ __ _ __ _ __ _ __ _ __ _ ___ b _ __ _ __ _ __ _ __ _ __ _ __ _ __ _c
a2_ _ __ _ __ _ __ _ __ _ __ _ _ b2 _ __ _ __ _ __ _ __ _ __ _ __ _ __ _c
a3_ _ __ _ __ _ __ _ __ _ __ _ _ b3 _ __ _ __ _ __ _ __ _ __ _ __ _ __ _c2
a4_ _ __ _ __ _ __ _ __ _ __ _ b4 _ __ _ __ _ __ _ __ _ __ _ __ _ ___ _c3
The result I need in a new table is:
Column1_ _ __ _ __ _ __ _ _ Column2_ _ __ _ __ _ __ _ ___ Column3
a3_ _ __ _ __ _ __ _ __ _ __ _ _ b3 _ __ _ __ _ __ _ __ _ __ _ __ _ __ _c2
a4_ _ __ _ __ _ __ _ __ _ __ _ b4 _ __ _ __ _ __ _ __ _ __ _ __ _ ___ _c3
I tried importing the values to a new table and applying a unique index on column 3 but the result i get out of it is
Column1_ _ __ _ __ _ __ _ _ Column2_ _ __ _ __ _ __ _ ___ Column3
a_ _ __ _ __ _ __ _ __ _ __ _ _ b _ __ _ __ _ __ _ __ _ __ _ __ _ __ _c
a3_ _ __ _ __ _ __ _ __ _ __ _ _ b3 _ __ _ __ _ __ _ __ _ __ _ __ _ __ _c2
a4_ _ __ _ __ _ __ _ __ _ __ _ b4 _ __ _ __ _ __ _ __ _ __ _ __ _ ___ _c3
1 answers
solution1
4 ACCPTED 2011-05-18 06:03:17
SELECT * FROM x WHERE Column3 NOT IN
(SELECT Column3 FROM x GROUP BY Column3 HAVING COUNT(*) > 1)
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