Apply set of data to another table

[Cultureshock]

How might I take a set of data from table 1 and apply it to table 2?

For instance.

Table 1:

id*, name, age

Table 2:

id, pet

 

How would I be able to view all the pets of people who are 18 (if 'id' is unique in table 1 and shared by all the pets owned by that person in table 2)?

 

does that make sense? >.<

[premiso]

Simply add a referencing ID as a foreign key in Table 2 to Table 1:

 

Table 2:

id, personid, pet

 

Assuming that person identifies the first table correctly, change person to be part of table 1's actual name.

[genericnumber1]

For your example, combined with premiso's, you could retrieve the information like this...

 

SELECT * FROM table1
INNER JOIN table2
ON table1.id = table2.personid
WHERE table1.age = 18

 

That SHOULD give you results you expect after you've renamed the table names. It's been a while since I've had to work with SQL (embarrassingly enough), so my knowledge of these things could be a bit rusty, but you get the general idea - joins are your friend.

[Cultureshock]

But how would that help if I have multiple ages? (i.e. grab all the pets from table 2 who's owners in table 1 are 18, 19, 23, or 9.)

 

The data searched for has to be dynamic.

[premiso]

SELECT * FROM table1
INNER JOIN table2
ON table1.id = table2.personid
WHERE table1.age IN(18, 19, 23,9) ORDER BY table1.age

 

Simple as that.

[Zane]

Using your example it would look like this

Table 1:
   id, name, age, pet
Table 2:
   id, pet

 

Then you would do

SELECT b.pet
FROM table1 AS a
INNER JOIN table2 as b
         ON a.pet = b.id
WHERE a.age = 18