Select first record in a One-to-Many relation using left join

Question

I\'m trying to join two tables using a left-join. And the result set has to include only the first record from the \"right\" joined table.

Lets say I have two tables

Answer 1

Another option: OUTER APPLY

If supported by the database, OUTER APPLY is an efficient and terse option.

SELECT *
FROM 
    Table_A a
OUTER APPLY
    (SELECT TOP 1 * 
    FROM Table_B b_1
    WHERE b_1.code = a.code
    ) b
;

This results in a left join to the indeterminate first matched record. My tests show it to be quicker than any other posted solution (on MS SQL Server 2012).