GROUP BY Modifiers

The GROUP BY clause allows a WITH ROLLUP modifier that causes extra rows to be added to the summary output. These rows represent higher-level (or [...]

GROUP BY (Aggregate) Functions

Name
Description

AVG()
Return the average value of the argument

BIT_AND()
Return bitwise and

BIT_OR()
Return bitwise or

BIT_XOR()(v4.1.1)
Return bitwise xor

COUNT(DISTINCT)
Return the count of a number of different values

COUNT()
Return a count of the number of rows returned

GROUP_CONCAT()(v4.1)
Return a concatenated string

MAX()
Return the maximum value

MIN()
Return the minimum value

STD(), STDDEV()
Return the population standard deviation

STDDEV_POP()(v5.0.3)
Return the population standard deviation

STDDEV_SAMP()(v5.0.3)
Return the sample standard deviation

SUM()
Return the sum

VAR_POP()(v5.0.3)
Return the population [...]

Information Functions

Name
Description

BENCHMARK()
Repeatedly execute an expression

CHARSET()(v4.1.0)
Return the character set of the argument

COERCIBILITY()(v4.1.1)
Return the collation coercibility value of the string argument

COLLATION()(v4.1.0)
Return the collation of the string argument

CONNECTION_ID()
Return the connection ID (thread ID) for the connection

CURRENT_USER(), CURRENT_USER
Return the username and hostname combination

DATABASE()
Return the default (current) database name

FOUND_ROWS()
For a SELECT with a LIMIT clause, the number [...]

Encryption and Compression Functions

Name
Description

AES_DECRYPT()
Decrypt using AES

AES_ENCRYPT()
Encrypt using AES

COMPRESS()(v4.1.1)
Return result as a binary string

DECODE()
Decodes a string encrypted using ENCODE()

DES_DECRYPT()
Decrypt a string

DES_ENCRYPT()
Decrypt a string

ENCODE()
Encode a string

ENCRYPT()
Encrypt a string

MD5()
Calculate MD5 checksum

OLD_PASSWORD()(v4.1)
Return the value of the old (pre-4.1) implementation of PASSWORD

PASSWORD()
Calculate and return a password string

SHA1(), SHA()
Calculate an SHA-1 160-bit checksum

UNCOMPRESS()(v4.1.1)
Uncompress a string compressed

UNCOMPRESSED_LENGTH()(v4.1.1)
Return the length of a string before compression

Date and Time Functions

This section describes the functions that can be used to manipulate temporal values. See Section 10.3, “Date and Time Types”, for a description of the range of values each date and time type has and the valid formats [...]

String Comparison Functions

Name
Description

<=>
NULL-safe equal to operator

=
Equal operator

>=
Greater than or equal operator

>
Greater than operator

IS NOT
Test a value against a boolean

IS NULL
NULL value test

IS
Test a value against a boolean

<=
Less than or equal operator

<
Less than operator

LIKE
Simple pattern matching

!=, <>
Not equal operator

NOT LIKE
Negation of simple pattern matching

SOUNDS LIKE(v4.1.0)
Compare sounds

Regular Expressions

Name
Description
NOT REGEXP
Negation of REGEXP

REGEXP
Pattern matching using regular expressions

RLIKE
Synonym for REGEXP

String Functions

Name
Description

ASCII()
Return numeric value of left-most character

BIN()
Return a string representation of the argument

BIT_LENGTH()
Return length of argument in bits

CHAR_LENGTH()
Return number of characters in argument

CHAR()
Return the character for each integer passed

CHARACTER_LENGTH()
A synonym for CHAR_LENGTH()

CONCAT_WS()
Return concatenate with separator

CONCAT()
Return concatenated string

CONV()
Convert numbers between different number bases

ELT()
Return string at index number

<=>
NULL-safe equal to operator

=
Equal operator

EXPORT_SET()
Return a string such that for [...]

MySQL – Introduction

PHP / MySQL Tutorial
MySQL is currently the most popular open source database server in existence. On top of that, it is very commonly used in conjunction with PHP scripts to create powerful and dynamic server-side applications.
MySQL has been criticized in the past for not supporting all the features of other popular and more expensive [...]