Function that represents a character in sql

The functions that represent a single character in SQL are: SUBSTRING: Extract the substring at the specified position (provides a starting position and a length of 1) CHAR: Creates Unicode characters (accepts Unicode code points) CHR: Creates ASCII characters (Accepts ASCII code points) UNICHAR: Creates Unicode characters (Accepts character names)

Functions in SQL that represent a character

There are several functions in SQL that can help obtain or represent a single character:

1. SUBSTRING function

SUBSTRING function extracts the substring at the specified position in the string . To get a single character, provide a starting position and a length of 1.

Syntax: SUBSTRING(string, start_position, length)

Example: Get the first character in the string "Hello":

<code>SELECT SUBSTRING('Hello', 1, 1);
-- 输出：H</code>

2. CHAR function

The CHAR function creates a single character from the Unicode character set. It accepts as argument an integer value that represents the code point of the Unicode character.

Syntax: CHAR(character_code)

Example: Get the Unicode character "A" (code point is 65):

<code>SELECT CHAR(65);
-- 输出：A</code>

3 . CHR function

The CHR function is similar to the CHAR function, but it accepts ASCII character codes as parameters.

Syntax: CHR(character_code)

Example: Get the ASCII character "A" (code point is 65):

<code>SELECT CHR(65);
-- 输出：A</code>

4 . UNICHAR function

The UNICHAR function creates a single character from the Unicode character set. It accepts a string argument that specifies the name of the character to be represented.

Syntax: UNICHAR(character_name)

Example: Get the Unicode character "asterisk" (name is "*):

<code>SELECT UNICHAR('*');
-- 输出：*</code>

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