SQL Joins and Where clauses

[Number4]

I've not taken any classes on SQL, just learned hands on.  I was trying to fix a query for someone and they had written their Joins in a fashion I was not used to.

For example, I write ALL of my Join statements then put one Where with Ands at the very end.

This individual had placed some Where clauses in a couple of the joins.  And these "where" clauses as I see, would normally just be below at the end of all the Joins.

So does SQL Developer read the Where/ands as it does each Join above?  Or is it more efficient to put Where's below each Join?

[echuong1 · Accepted solution]

Are you looking to replicate the joins and where clause in Designer, or is this a general SQL syntax question? In Alteryx, I recommend having the where clauses embedded into the input. From there, you will be joining only a subset of the records and will make processing more efficient.

With regard to SQL syntax, something like Stackoverflow may be a more appropriate place for your question.

https://stackoverflow.com/questions/354070/sql-join-where-clause-vs-on-clause

https://stackoverflow.com/questions/15483808/sql-join-where-to-place-the-where-condition 

Hope this helps!

[Number4]

Thanks.  I was searching the web for a SQL answer, but answers are always scattered and on this, nothing hit.

Your second link was helpful on the SQL side.

This persons answer, hopefully correct, is what I was looking for:

"I think the faster way is to put the filter in the where clause, because it will procees that filter in the where first , and then the join clause, so there will be no need of permutation of filters." - Artemination

I use a lot of SQL statements to bring in data.