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Base de données, Tables, Vues, Index et syntaxe SQL
>This seems like such a simple problem <g>.
>
>I have a table of unique IDs with a second column for frequency (every frequency is > 0). I have another table with all possible unique IDs. I want to merge the two to produce a list of all possible unique ideas with their frequency with zero for those that are not in the first table.
>
>So if Table1 contains IDs of 1, 2, 4, and 6 and Table2 contains IDs of 1 through 7, then I want it to produce a list like this:
>
> ID FREQ
> 1 12
> 2 117
> 3 0 (or .NULL.)
> 4 94
> 5 0 (or .NULL.)
> 6 48
> 7 0 (or .NULL.)
>
>I thought that the command was :
>
> SELECT ID, FREQ from Table1;
> RIGHT JOIN Table2 on Table1.ID=Table2.ID
>
>But that produces .NULL.s in the first column. What am I doing wrong?
>
>If Table2 has 300k IDs in it, would it be faster to join Table2 to Table1 as opposed to joining Table1 to Table2? I can't figure out the SQL JOIN command for that approach either.
>
>Thanks for any help.
>
>(PS: I know how to do this with SET RELATION)
>
>-Bob
Try SELECT Table2.ID,Table1.FREQ ;
FROM Table2 LEFT JOIN Table1 ON ;
Table2.ID = Table1.ID
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