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POHow to do a JOIN from two different columns to the same column on a separate table
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  1. POHow to do a JOIN from two different columns to the same column on a separate table
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    copied!<p>I have two columns on one table that reference the same column on a second table in order to obtain the name that relates to an specified ID.</p> <p>Below is the query that I am using that is not working. The two LEFT JOINS on the invTypes causes the problem. I have read and read and have been racking my brain on this. I cannot for the life of me figure out how to make this return the names that belong to the IDs that appear in two separate locations in the main table.</p> <p>THings to note with out posting the entire database structure (which is huge)</p> <p>both the <code>typeID</code> and <code>itemTypeID</code> are present on the main table. Each of those references the same <code>typeID</code> column in the <code>invTypes</code> table. The <code>invTypes</code> table contains the name that corresponds to said ID. </p> <p>Additionally, in the SELECT part of the statement, the <code>typeName</code> comes from the <code>invTypes</code> and the <code>stationName</code> comes from the <code>staStations</code> table. </p> <p>The main question is, if the invTypes.<code>typeName</code> is referenced two times from two columns, how do i 1: properly join the tables to those two points and 2: how do i tell the difference in the two invTypes.<code>typeName</code> that is to be returned if the two JOIN statements can be made.</p> <pre><code>SELECT `logTime`,`itemID`,`typeName`,`actorName`,`stationName`,`action`,`passwordType`, `quantity`,`oldConfiguration`,`newConfiguration` FROM eve_container_audit LEFT JOIN invTypes ON eve_container_audit.typeID = invTypes.typeID LEFT JOIN invTypes ON eve_container_audit.itemTypeID = invTypes.typeID LEFT JOIN staStations ON eve_container_audit.locationID = staStations.stationID </code></pre>
 

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