ASCII Characters in Database

ASCII:

• American Standard Code for Information Interchange.
• Computer can understand only numbers.
• ASCII is the numeric representation of a character.

Syntax:

SELECT CHAR(Expression)

              A string function that converts an int ASCII code to a character.

Return type is CHAR.

     Expression is integer value i.e. range from 0 to 255

Example

SELECT CHAR(97) AS [ASCII Character of Number 97]

SELECT ASCII('a')  AS [ASCII Number of  Character a]

SELECT CHAR(65) AS [ASCII Character of Number 67]

SELECT ASCII('A') AS [ASCII Number of  Character A]

Output

ASCII Values:

1) Characters Set 0-31

        First 32 Characters in the ASCII table are unprintable.

2) Characters Set 32-127

        Characters from 32-127 are common for all which represent letters, digits, punctuation marks & miscellaneous symbols.

3) Character Set 128-255

         Characters from 128-255 contains the Microsoft Latin-1 extended characters.

--Example to display All Number & ASCII characters

;WITH AllNumbers AS

(

SELECT 0 AS First_No

            UNION ALL

            SELECT First_No+1

            FROM AllNumbers

            WHERE First_No<255

)

SELECT First_No as [Numbers],

               CHAR(First_No) as [ASCII Value]

FROM AllNumbers

              OPTION (MAXRECURSION 255)

Syntax in Oracle

           CHR(expression [using NCHAR_CS])

Syntax in IBM DB2, Sybase

           CHR(Expression)