On 10/23/2013 8:15 AM, Taco Mathijs Hillenaar-Meerveld wrote:
Good afternoon,
i haven't done much with php and Mysql the past 2 years so my knowledge is
not really up-to-date.
i'm not a hero when it comes to math. actually, it's a weakness but trying
to fix that.
i made a query where i compare 2 tables against eachother and then i want
to see a table that shows me results: the Relation + Surname should match.
i have chosen for those two because Surname was a required input and all
contacts must have a relation. also, in those tables there are fields that
have completely messed up information that shouldn't be there in the first
place, phone numbers as names f.e..
that aside i made this query:
$sql = 'SELECT table_a1.Surname, table_a2.Relation, table_a1.City
FROM table_a1
INNER JOIN table_a2
ON table_a1.Relation=table_a2.Relation';w
I get a row back. my question:
is this an appropiate and common way to get this job done? im NOT used to
dig deep in this kind of stuff but i can see in the future i will need a
few handy scripts.
tips and advice are very welcome.
You really don't need the INNER JOIN to do this. Your task ( to find
those records that have matching relation values can be done very
simply. Replace it all with :
"select a1.Surname, a1.City, a2.Relation
FROM table_a1 a1, table_a2 a2
where a1.Relation = a2.Relation"
(Note my use of the simpler alias instead of the full table name.)
I realize that this is probably a simplification of your true goal, but
just in case it is not, I point out that I don't see the value of this
particular query. You are looking for matching records but you don't
pull any information from the matched records that you don't already
have in the a1 table. Do I assume that you will be adding more fields
in your selection?
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