Question

Im sure this will be pretty simple for a t-sql guru.

I have the following result from a table

idMain  IdSecondary  TextValue
1       1            text1
1       2            text2
2       5            text3
2       6            text5

And I want to obtain the first occurence of the idMain only.

The result should be like this.

idMain  idSecondary  TextValue
1       1            text1
2       5            text3

How can I achieve this?

Answer 1

You should be able to join with a sub query, as in the following example. This assumes that by “first” you mean the lowest idSecondary:

SELECT t.idMain, sub_t.minSecondary, t.textValue
FROM   your_table t
JOIN   (SELECT   idMain, MIN(idSecondary) minSecondary
        FROM     your_table
        GROUP BY idMain) sub_t ON (sub_t.idMain = t.idMain);