Node.js MySQL SUBSTRING() Function

SUBSTRING() function is a built-in function in MySQL that is used to get a substring of input string between given range inclusive.

Syntax:

SUBSTRING(input_string, from, length)

Parameters: It takes three parameters as follows:

• input_string: It is the given string for which the substring will be executed.
• from: The substring will be taken from this position.
• length: It is the length of the substring.

Return Value: It returns a substring of input string between a given starting position and length. If length is out of string then the extra part is ignored.

Module Installation: Install the mysql module using the following command:

npm install mysql

Database: Our SQL publishers table preview with sample data is shown below:

Example 1:

index.js

const mysql = require("mysql");

let db_con  = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: '',
    database: 'gfg_db'
});

db_con.connect((err) => {
    if (err) {
      console.log("Database Connection Failed !!!", err);
      return;
    }

    console.log("We are connected to gfg_db database");

    // Notice the ? in query
    let query = `SELECT SUBSTRING("GeeksforGeeks",
                 8, 20) AS SUBSTRING_Output`;

    db_con.query(query, (err, rows) => {
        if(err) throw err;

        console.log(rows);
    });
});

Run the index.js file using the following command:

node index.js

Output:

Example 2:

index.js

const mysql = require("mysql");

let db_con  = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: '',
    database: 'gfg_db'
});

db_con.connect((err) => {
    if (err) {
      console.log("Database Connection Failed !!!", err);
      return;
    }

    console.log("We are connected to gfg_db database");

    // Notice the ? in query
    let query = `SELECT SUBSTRING(name, 1, 4)
            AS SUBSTRING_Name FROM publishers`;

    db_con.query(query, (err, rows) => {
        if(err) throw err;

        console.log(rows);
    });
});

Run the index.js file using the following command:

node index.js

Output: