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POSQL query for join table and multiple values
 

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    <p>So I have three tables that are involved in my problem, 2 regular tables and a join table for a has many and belongs to many relationship. They look like this:</p> <pre><code>table1 --id --data table2 --id --data table1_table2 --table1_id --table2_id </code></pre> <p>So, my question is how I would query (using a join) for something that would have one or more values in the table1_table2 for one item in table1. For instance:</p> <pre><code>Table 1 +----------+ |id | data | +----------+ |1 | none | +----------+ |4 | match| +----------+ Table 2 +----------+ |id | data | +----------+ |1 | one | +----------+ |2 | two | +----------+ table1_table2 +----------------------+ |table1_id | table2_id | +----------------------+ |1 | 1 | +----------------------+ |4 | 1 | +----------------------+ |4 | 2 | +----------------------+ </code></pre> <p>I need a query that would match Table 1 row id 4 because it has a link via the join to both row 1 and 2 from table 2. If this is confusing please ask anything.</p> <p>Maybe I was a bit unclear, I am using table1_table2 as a join not as a from. I need to make sure it matches 1 and 2 both from table 2.</p> <p>Here is my query so far...</p> <pre><code>SELECT DISTINCT table1.id, table2.data FROM table1 LEFT JOIN table1_table2 ON table1.id = table1_table2.table1_id LEFT JOIN table2 ON table2.id = table1_table2.table2_id </code></pre> <p>I need a where that will make that for an entry in table 1 it matches both 1 and 2 from table 2.</p> <p>The output I am looking for would be:</p> <pre><code>+---------------------+ |table1.id|table2.data| +---------------------+ |4 |one | +---------------------+ |4 |two | +---------------------+ </code></pre>
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    1. COAre you learning SQL (i.e. is this homework?) This is a very obvious follow up question to one of your previous questions (http://stackoverflow.com/questions/10726322/sql-join-using-a-join-table-from-rails). I don't have a problem with you learning on SO but you might want to tag your question [homework] if it is.
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    2. COThis is not for school.
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    3. COThough the question is related to a previous question, it isn't actually using the same tables. I am renaming the tables I am actually using.
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