content_image/822566.jpg content_image/822573.jpg content_image/822574.jpg
mysql> SELECT HEX(@v1), HEX(@v2); 

<img src='content_image/822566.jpg'>

The displayed result appears similar for both bit operations, but the result without _binary  is a BIGINT value, whereas the result with _binary  is a binary string. Due to the difference in result types, the displayed values differ: High-order 0 digits are not displayed for the numeric result. 

## 9.1.5 Bit-Value Literals 

Bit-value literals are written using b’ val ’  or 0b val  notation. val  is a binary value written using zeros and ones. Lettercase of any leading b  does not matter. A leading 0b  is case-sensitive and cannot be written as 0B . 

Legal bit-value literals: 

b’01’ B’01’ 0b01 

Illegal bit-value literals: 

b’2’ (2 is not a binary digit) 0B01 (0B must be written as 0b) 

By default, a bit-value literal is a binary string: 

mysql> SELECT b’1000001’, CHARSET(b’1000001’); 

<img src='content_image/822573.jpg'>

mysql> SELECT 0b1100001, CHARSET(0b1100001); 

<img src='content_image/822574.jpg'>

A bit-value literal may have an optional character set introducer and COLLATE  clause, to designate it as a string that uses a particular character set and collation: 

[_ charset_name ] b’ val ’ [COLLATE collation_name ] 

Examples: 

SELECT _latin1 b’1000001’; SELECT _utf8 0b1000001 COLLATE utf8_danish_ci; 

The examples use b’ val ’  notation, but 0b val  notation permits introducers as well. For information about introducers, see Section 10.3.8, “Character Set Introducers” . 

In numeric contexts, MySQL treats a bit literal like an integer. To ensure numeric treatment of a bit literal, use it in numeric context. Ways to do this include adding 0 or using CAST(... AS UNSIGNED) . For example, a bit literal assigned to a user-defined variable is a binary string by default. To assign the value as a number, use it in numeric context: 

mysql> SET @v1 = b’1100001’; 

