Oracle ASCII function
Description
The ASCII() function returns the decimal representation of the first character of a character expression.
Character expression can be the following data types:
- CHAR
- VARCHAR2
- NCHAR
- NVARCHAR2
The function does not support CLOB data directly. However, CLOBs can be passed in as arguments through implicit data conversion.
Note : If your database character set is 7-bit ASCII, then this function returns an ASCII value. If your database character set is EBCDIC Code, then this function returns an EBCDIC value.
Uses of Oracle ASCII Function
- Character to ASCII Conversion: Convert the first character of a string to its ASCII decimal value.
- Filtering Data: Select records based on the ASCII value of characters, such as filtering names starting with a specific letter.
- Character Encoding Analysis: Analyze character encoding by retrieving ASCII values of characters.
- String Comparison: Compare strings based on the ASCII values of their characters for sorting or other operations.
Syntax:
ASCII(character_expression)
Parameters:
| Name | Description |
|---|---|
| character_expression | Is an expression of the above data types mentioned in the list. |
Return Value Type:
NUMBER.
Applies to:
Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i, Oracle 8i
Examples: Oracle ASCII function
The following example returns employees whose first names begin with the letter 'C', whose ASCII equivalent is 67:
SQL> SELECT first_name FROM employees
2 WHERE ASCII(SUBSTR(first_name, 1, 1)) = 67
3 ORDER BY last_name;
Sample Output:
FIRST_NAME -------------- Curtis Charles Christopher Clara