on-clause - w3toppers.com

What’s the difference between “where” clause and “on” clause when table left join?

The where clause applies to the whole resultset; the on clause only applies to the join in question. In the example supplied, all of the additional conditions related to fields on the inner side of the join – so in this example, the two queries are effectively identical. However, if you had included a condition … Read more

SQL JOIN – WHERE clause vs. ON clause

They are not the same thing. Consider these queries: SELECT * FROM Orders LEFT JOIN OrderLines ON OrderLines.OrderID=Orders.ID WHERE Orders.ID = 12345 and SELECT * FROM Orders LEFT JOIN OrderLines ON OrderLines.OrderID=Orders.ID AND Orders.ID = 12345 The first will return an order and its lines, if any, for order number 12345. The second will return … Read more