SQL Reference
Table Of Contents
- Chapter 1 Introduction
- Chapter 2 Supported standards
- Support for Unicode characters
- SQL statements
- SELECT statement
- SQL clauses
- FROM clause
- WHERE clause
- GROUP BY clause
- HAVING clause
- UNION operator
- ORDER BY clause
- OFFSET and FETCH FIRST clauses
- FOR UPDATE clause
- DELETE statement
- INSERT statement
- UPDATE statement
- CREATE TABLE statement
- TRUNCATE TABLE statement
- ALTER TABLE statement
- CREATE INDEX statement
- DROP INDEX statement
- SQL expressions
- SQL functions
- FileMaker system objects
- Reserved SQL keywords
- Index
Chapter 2 | Supported standards 28
Operator precedence
As expressions become more complex, the order in which the expressions are evaluated
becomes important. This table shows the order in which the operators are evaluated. The
operators in the first line are evaluated first, and so on. Operators in the same line are evaluated
left to right in the expression.
Precedence Operator
1 Unary '-', Unary '+'
2 ^, **
3 *, /
4 +, -
5 =, <>, <, <=, >, >=, Like, Not Like, Is Null, Is Not Null, Between, In, Exists, Any, All
6 Not
7 AND
8 OR
The following example shows the importance of precedence:
WHERE salary > 40000 OR hire_date > (DATE '2008-01-30') AND dept =
'D1
01'
Because AND is evaluated first, this query retrieves employees in de
partment D101 hired after
January 30, 2008, as well as every employee making more than $40,000, no matter what
department or hire date.
To force the clause to be evaluated in a different order, use parenth
eses to enclose the conditions
to be evaluated first. For example:
WHERE (salary > 40000 OR hire_date > DATE '2008-01-30') AND dept =
'D1
01'
retrieves employees in department D101 that either make more than
$40,000 or were hired after
January 30, 2008.