Use MySQL's SOUNDEX function to calculate the phonetic encoding of a string

Use MySQL's SOUNDEX function to calculate the phonetic encoding of a string

Introduction:
When performing data analysis and processing, sometimes it is necessary to phonetically encode a string, that is, convert the string into its pronunciation Similar encoding. MySQL provides a very useful function SOUNDEX, which can implement speech encoding of strings. This article will introduce how to use MySQL's SOUNDEX function to calculate the phonetic encoding of a string and provide corresponding code examples.

1. Introduction to SOUNDEX function
The SOUNDEX function is a built-in function in MySQL, used to calculate the phonetic encoding of a string. It accepts a string as argument and returns a four-character encoding. The calculation method of the SOUNDEX function is to map the letters in the string to the corresponding numbers, and then generate the encoding according to certain rules.

2. Use of SOUNDEX function
Using the SOUNDEX function is very simple. You only need to pass the string to be encoded as a parameter to the SOUNDEX function. The following is an example of using the SOUNDEX function to calculate the speech encoding:

SELECT SOUNDEX('hello world');

Executing the above SQL statement will return the speech encoding of the string "hello world".

3. Speech encoding rules
The encoding rules of the SOUNDEX function are as follows:

1. Map letters into corresponding numbers according to their pronunciation. For example, B, F, P, and V all map to 1, C, G, J, K, Q, S, X, and Z all map to 2, D and T map to 3, L maps to 4, and M and N map to is 5, R maps to 6.
2. Remove all adjacent identical numbers, leaving only one.
3. If the length of the encoding is less than 4 characters, pad it with 0s.

4. Sample code
The following is a sample code to demonstrate how to use the SOUNDEX function to calculate the phonetic encoding of a string:

CREATE TABLE person (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100),
    soundex_code CHAR(4)
);

INSERT INTO person (name, soundex_code)
VALUES
    ('John Smith', SOUNDEX('John Smith')),
    ('Robert Johnson', SOUNDEX('Robert Johnson')),
    ('David Lee', SOUNDEX('David Lee'));

SELECT * FROM person;

Executing the above code will create a A table named person with three records inserted. Each record contains a name and corresponding phonetic code. Finally, query the contents of the person table, and the results will display each person's name and corresponding speech code.

Summary:
Using MySQL's SOUNDEX function, you can easily calculate the phonetic encoding of a string, thereby realizing phonetic processing of the string. This article provides a brief introduction to the use of the SOUNDEX function and provides corresponding code examples. Readers can further understand and apply the SOUNDEX function to optimize their data processing processes according to their own needs.

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