Detailed description of ASCII and ORD functions in mysql

In mysql, ASCII and ORD functions are all functions that convert characters into ascii code values. Next I will introduce to you the ASCII and ORD usage in mysql.

1. ASCII (str1)

Returns the ASCII code value of the leftmost character of the str string. If str is a Null String, 0 is returned. If 'str' is NULL, return NULL

Example:
1.

The Code is as follows:	Copy code
Mysql> select ascii ('Hi '); + ----- + | Ascii ('Hi') | + ----- + | 1, 104 | + ----- + 1 row in set

104 is the ASCII value of h

2. Output ASCII values of B and B

The Code is as follows:	Copy code
Mysql> select ascii ('B') AS Lower_Case, ASCII ('B') AS Upper_Case; + ---- + | Lower_Case | Upper_Case | + ---- + | 98 | 66 | + ---- + 1 row in set

3. Use ASCII functions in the where statement

Output Data whose ASCII value is less than 70 at the beginning of aut_name

The Code is as follows:	Copy code
SELECT aut_name, ASCII (aut_name) as "ASCII value of 1st character" FROM author Where ascii (aut_name) <70;

4. The output field does not contain any data without ASCII values.

The Code is as follows:	Copy code
SELECT * FROM table_name where not column_to_check REGEXP '[A-Za-z0-9.,-]';

5. Use it with SUBSTRING to calculate the second ASCII value after the string

The Code is as follows:	Copy code
Mysql> select ASCII (SUBSTRING ('database', 2, 1 )); + ------------ + | ASCII (SUBSTRING ('database', 2, 1) | + ------------ + | 97 | + ------------ + 1 row in set

2. ord Functions

ORD (str)

If the leftmost character of a string 'str' is a multi-byte character

The Code is as follows:	Copy code
(First byte ASCII code) * 256 + (second byte ASCII code) [* 256 + third byte ASCII code...]

Returns the ASCII code value of a character to return the multi-byte code. If the leftmost character is not a multi-byte character. Returns the same value as that returned by the ASCII () function.

The Code is as follows:	Copy code
1 mysql> select ORD ('2 '); 2-> 50