Join query with foreign key

[gubbachchi]

Hi,

How to use foreign key with join queries. I have used the query

SELECT first_name,last _name,user_emai l from Info,Registry WHERE user_id='1';

where user_id = foreign key
first_name,last _name are in table Info
user_email in table Registry
user_id is a foreign key which references the parent key present in seperate database.
. The query is returning empty set even though there are results in mysql table.

What is the reason for this. Can anyone help me.

Thanks

[cvraghavan1979]

join query with foreign key

Hi,

How to use foreign key with join queries. I have used the query

SELECT first_name,last _name,user_emai l from Info,Registry WHERE user_id='1';

where user_id = foreign key
first_name,last _name are in table Info
user_email in table Registry
user_id is a foreign key which references the parent key present in seperate database.
. The query is returning empty set even though there are results in mysql table.

What is the reason for this. Can anyone help me.

Thanks

Hi,

u've written that the user_id is in a separate database, then how u r linking the tables info and registry. to perform a join there should b atleast one column in common, but u'ven't used to common column in query. may b that's the pbm.

regards,
vijay

[cvraghavan1979]

Hi,

How to use foreign key with join queries. I have used the query

SELECT first_name,last _name,user_emai l from Info,Registry WHERE user_id='1';

where user_id = foreign key
first_name,last _name are in table Info
user_email in table Registry
user_id is a foreign key which references the parent key present in seperate database.
. The query is returning empty set even though there are results in mysql table.

What is the reason for this. Can anyone help me.

Thanks

Hi,

u've written that the user_id is in a separate database, then how u r linking the tables info and registry. to perform a join there should b atleast one column in common, but u'ven't used to common column in query. may b that's the pbm.

regards,
vijay