ASCII
The ASCII function in SQL returns the ASCII value for the first character of the specified string.
Syntax
The syntax for the ASCII function in SQL is:
ASCII ( single_character_text )
Parameters
single_character_text
: This is the string that the ASCII value should be returned for. It should be a single character string.
Examples
Let's consider a few examples to understand how to use the ASCII function.
To get the ASCII value of a character:
VALUES(ASCII('A'));
This will return 65
, which is the ASCII value for 'A'.
Please note that the ASCII function expects a single character value. If a string with more than one character is passed, it will throw an error. For instance:
VALUES(ASCII('AB'));
This will throw an error because 'AB' contains more than one character.
You can also use the ASCII function in a SELECT statement. Consider the following table named 'Ascii':
id | text |
---|---|
1 | 'F' |
CREATE TABLE Ascii (
id INTEGER,
text TEXT
);
INSERT INTO Ascii VALUES (1, 'F');
You can select the ASCII value of the 'text' column:
SELECT ASCII(text) AS ascii FROM Ascii;
This will return 70
, which is the ASCII value for 'F'.
The ASCII function can also take a string directly:
SELECT ASCII('a') AS ascii FROM Ascii;
This will return 97
, which is the ASCII value for 'a'.
If a non-ASCII character is passed to the function, it will throw an error. For instance:
SELECT ASCII('ㄱ') AS ascii FROM Ascii;
This will throw an error because 'ㄱ' is not an ASCII character.
If no argument is passed to the ASCII function, it will also throw an error:
SELECT ASCII() AS ascii FROM Ascii;
This will throw an error because the ASCII function expects one argument.
Remember, the ASCII function expects a single character. If the column value contains more than one character, it will throw an error:
INSERT INTO Ascii VALUES (1, 'Foo');
SELECT ASCII(text) AS ascii FROM Ascii;
This will throw an error because 'Foo' contains more than one character.