We can use ALTER TABLE statement to add a new column in an existing table.

Syntax:

ALTER TABLE <table_name> ADD <column_name> datatype;

Example:

// create table
CREATE TABLE employees (
    id int,
    first_name varchar(255),
    last_name varchar(255),
    email varchar(255),
    City varchar(255),
    state varchar(255),
    country varchar(255)
);

// Alter table to add zip_code column
ALTER TABLE employees ADD zip_code varchar(10);