(mysql.info.gz) Functions
Info Catalog
(mysql.info.gz) Column types
(mysql.info.gz) Top
(mysql.info.gz) SQL Syntax
12 Functions and Operators
**************************
Expressions can be used at several points in SQL statements, such as in
the `ORDER BY' or `HAVING' clauses of `SELECT' statements, in the
`WHERE' clause of a `SELECT', `DELETE', or `UPDATE' statement, or in
`SET' statements. Expressions can be written using literal values,
column values, `NULL', functions, and operators. This chapter
describes the functions and operators that are allowed for writing
expressions in MySQL.
An expression that contains `NULL' always produces a `NULL' value
unless otherwise indicated in the documentation for a particular
function or operator.
* By default, there must be no whitespace between a function name
and the parenthesis following it. This helps the MySQL parser
distinguish between function calls and references to tables or columns
that happen to have the same name as a function. Spaces around function
arguments are permitted, though.
You can tell the MySQL server to accept spaces after function names by
starting it with the `--sql-mode=IGNORE_SPACE' option. Individual client
programs can request this behavior by using the `CLIENT_IGNORE_SPACE'
option for `mysql_real_connect()'. In either case, all function names
will become reserved words. Server SQL mode.
For the sake of brevity, most examples in this chapter display the
output from the `mysql' program in abbreviated form. Instead of showing
examples in this format:
mysql> SELECT MOD(29,9);
+-----------+
| mod(29,9) |
+-----------+
| 2 |
+-----------+
1 rows in set (0.00 sec)
This format is used instead:
mysql> SELECT MOD(29,9);
-> 2
Menu
* Non-typed Operators Operators
* Control flow functions Control Flow Functions
* String functions String Functions
* Numeric Functions Numeric Functions
* Date and time functions Date and Time Functions
* Fulltext Search Full-Text Search Functions
* Cast Functions Cast Functions and Operators
* Other Functions Other Functions
* Group by functions and modifiers Functions and Modifiers for Use with `GROUP BY' Clauses
Info Catalog
(mysql.info.gz) Column types
(mysql.info.gz) Top
(mysql.info.gz) SQL Syntax
automatically generated byinfo2html