3个表之间的内部联接

Question

i have these table in database:

country:

id      country
------------------
1       USA
2       Brazil

and segment table:

id      country
------------------
1       USA
2       Brazil

i have a third table:

Id segment_id country_id

where segment_id is a foreign key of id in segment table

and country_id is a foreign key of id in country table

myquestion is:

how to select from the other table with inner join of the 3 tables,

i need to show the name of the country plus for every country show all the segments in a dropdown menu if anyone could help me

thank u

Answer 1

you just try this

$sql = select * from third_table 
       inner join country on third_table.country_id = country.id
       inner join segment on third_table.segment_id = segment.id
$res = mysql_query($sql);

   'or'


   select * from TableA A 
   inner join TableB B on A.Column=B.Column 
   inner join TableC C on A.Column=C.Column

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