Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I’ve got a bunch of classes that describe database schema: Table,Field,ForeignKey.
Tables have ForeignKeys list and Fields list.
Now I would like to generate SELECT statement with all the joins that are described in ForeignKey instances.
The question is: is order of tables relevant for the query time? Another words – do I have to care or is it done automatically for me by the db engine?
To the optimizer, no — it doesn’t matter.
For sake of readability and maintainance, you might want to consider laying the FROM and JOIN clauses out in a manner that reads well. If only dealing with INNER joins, there’s no issue but OUTER JOINS I generally define after the FROM clause and use LEFT JOIN syntax exclusively. But that’s a matter of style & taste…