Duplicate results

[OriginalBoy]

Hey,

 

I need to find duplicate results from different mysql tables. So I need to search the email fields in the tables and then it returns back anything thats in them all.

 

I've been looking through tutorials and here is what i have got...

 

SELECT email

FROM design3

INNER JOIN flash3

ON first_table.keyfield = second_table.foreign_keyfield

 

this dnt seem to be working i got this guide from w3schools any advice, and can I join like 3 or 4 together to search through

 

 

 

[cooldude832]

are Table 1 and Table 2 identical tables?

[OriginalBoy]

Yes they are

[Ken2k7]

SELECT email
FROM design3
INNER JOIN flash3
ON first_table.keyfield = second_table.foreign_keyfield

 

1. What table is the email you want to select?

2. If you're selecting from design3 INNER JOIN flash3, where did first_table and second_table come in?

[genericnumber1]

yeah, you'll need to change

 

ON first_table.keyfield = second_table.foreign_keyfield

 

to match your table's layout.. maybe something like

 

ON design3.id = flash3.id

 

?

[OriginalBoy]

Ok I kinda get it the email is in both tables and I need to find it if any are in both

[Ken2k7]

SELECT design3.email
FROM design3
INNER JOIN flash3
ON design3.keyfield = flash3.foreign_keyfield

?

[OriginalBoy]

SELECT design3.email
FROM design3
INNER JOIN flash3
ON design3.keyfield = flash3.foreign_keyfield

?

 

I get this back...

 

#1054 - Unknown column 'design3.keyfield' in 'on clause'

 

[genericnumber1]

you change 'keyfield' to the field of the first table that corresponds to the 'foreign_keyfield' of the second table

 

edit:

for instance, if you have a table "classes"...

classID/className

1/math

2/science

3/english

 

and you have a if you have a table "students"...

 

classID/name

3/john

1/jane

3/carl

 

the query SELECT * FROM students INNER JOIN classes ON students.classID = classes.classID

 

would return a table connecting the students to their respective classes... eg carl (in the result column students.name) would be on the same result row as english (in the result column classes.className).