SQL query, where = value of another table

Question

I want to make a query that simply makes this, this may sound really dumb but i made a lot of research and couldn't understand nothing.

Imagine that i have two tables (table1 and table2) and two columns (table1.column1 and table2.column2).

What i want to make is basically this:

SELECT column1 FROM table1 where table2.column2 = '0'

I don't know if this is possible.

Thanks in advance,

Answer 1

You need to apply join between two talbes and than you can apply your where clause will do work for you

select column1 from table1 
   inner join table2 on table1.column = table2.column
   where table2.columne=0

for join info you can see this

Reading this original article on The Code Project will help you a lot: Visual Representation of SQL Joins.

Find original one at: Difference between JOIN and OUTER JOIN in MySQL.

Answer 2

SELECT column1 FROM table1 t1
where exists (select 1 from table2 t2 
    where t1.id = t2.table1_id and t2.column2 = '0')

assuming table1_id in table2 is a foreign key refering to id of table1 which is the primary key