SQL WHERE

Internal

• SQL SELECT
• SQL UPDATE
• SQL DELETE

TODO

TO PROCESS: https://learning.oreilly.com/library/view/learning-sql-3rd/9781492057604/ch04.html

Overview

The WHERE clause is the mechanism for filtering out unwanted data from the result set. The WHERE clause can be used with SELECT, UPDATE and DELETE, but not with INSERT. The WHERE clause may contain an arbitrary number of filter conditions separated by AND, OR and NOT operators, and optionally grouped together with parentheses.

  FROM <filter_condition> AND|OR <filter_condition> ...

SELECT * FROM person WHERE person.name = 'Alice' AND (person.eye_color = 'blue' OR person.eye_color = 'black');

Filter Conditions

NULL in Conditions

Also see:

NULL

Using Parentheses

If the WHERE clause includes three or more conditions combined with AND, OR or NOT, you should use parentheses to make your intent clear.