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@NogDogDec 15.2020 — #
Whether there are any performance differences, I'd have to test it before I'd say one way or another. (DBMS's are pretty smart these days at optimizing queries.) Also, if you use naming conventions such that the columns to be joined on across tables are the same name, I like using the
@NogDogDec 15.2020 — #
Yeah, the
Most important starting rule of thumb: any columns being used in
Benefits of using the keyword JOIN in SQL query explicitly?
Hi SQL experts,
I just figured out this query:
[code]SELECT fullname from an, Profiles
WHERE an.lid=Profiles.lid AND an.type=Profiles.type
AND Profiles.lid_P=99 AND Profiles.type_P=’Ulli’
It works fine without using the keyword JOIN.
However when reading joined queries of others they are always using LEFT JOIN, INNER JOIN etc.
My question is: Is my version just a simplified one or are there benefits when using the JOIN instruction explicitly, e. g. better performance or hints to the RDBMS for optimising?
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@NogDogDec 15.2020 — #SELECT fullname from an, ProfilesanProfilesJOINWhether there are any performance differences, I'd have to test it before I'd say one way or another. (DBMS's are pretty smart these days at optimizing queries.) Also, if you use naming conventions such that the columns to be joined on across tables are the same name, I like using the
USING()<i>
</i>SELECT a.col1, b.col2
FROM table_a a
INNER JOIN table_b b USING(table_a_id)
0
@NogDogDec 15.2020 — #>@Sempervivum#1625940 I didn't dive into the types of JOIN yet but seems to be worthwile to do so.
Yeah, the
LEFT JOININNER JOINEXPLAINMost important starting rule of thumb: any columns being used in
JOINWHERE