Select without duplicate values in one column

Question

My construction:

INSERT INTO ... ( SELECT ... FROM .. JOIN ... ON ... WHERE ... ORDER BY ... )

Short description: I'm using Select to insert data from 2 tables (using JOIN) to another table. The result of Select is something like (after order by):

col_a  |  col_b  |  col_c |        col_d

1111       44         xxx            yyy
1111       66         xxx            yyy
2222       12         aaa            bbb
3333       55         ccc            ddd
3333       68         xxx            yyy

If the row is duplicated (col_c) i want to insert to my table first matched row.

Example of result should be like this:

col_a  |  col_b  |  col_c |        col_d

1111       44         xxx            yyy
2222       12         aaa            bbb
3333       55         ccc            ddd

Please add the query like you already have.... on which column do you want to order by? And you only want to check on duplicate in col_c? — arnoudhgz
– arnoudhgz, Commented Feb 11, 2015 at 19:30

Ramie · Accepted Answer · 2015-02-11 19:31:03Z

2

Use the GROUP BY function

(SELECT ... FROM .. JOIN ... ON ... WHERE ... ORDER BY ... GROUP BY [col_c])

answered Feb 11, 2015 at 19:31

Ramie

1,2112 gold badges18 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Chris Over a year ago

GROUP BY is executing before ORDER BY .. I want to first ORDER my result and then eliminate duplicates

Chris · Accepted Answer · 2015-02-11 20:05:28Z

0

I think I found a solution. I create unique key for the col in table. After that INSERT IGNORE is everyhing what I need :)

answered Feb 11, 2015 at 20:05

Chris

6721 gold badge7 silver badges23 bronze badges

Collectives™ on Stack Overflow

Select without duplicate values in one column

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related