Adding Columns with SQL Server ALTER TABLE: A Guide

1. How to Add A New Column to a Table in SQL? janbasktraining.com/blog/add-a-new-column-to-a-table-in-sql/ May 18, 2023 Introduction Every time a table is created in SQL Server using T-SQL, you need to specify all the columns for that table with their data type and constraints. But what happens when you suddenly have to add a new column in a table in SQL? After all, dropping a table and starting again is not an option here. The other option is taking the backup and creating it again after dropping the existing table. But these options are not optimum and cannot be considered good choices for programmers. In SQL, you can create new columns using an ALTER TABLE statement that can also be used to add, modify, or delete columns in the existing table. It can also add or drop various constraints on the existing table. Before we start with the actual discussion of “how to create a new column SQL to an existing table,” let us first learn how to create a table in SQL Server using a query. To create columns in SQL, you must enhance your SQL skills. Do register yourself for online SQL server training to give a competitive edge to your career. Creating a table in the SQL involves the name of a table, the definition of columns, and its associated data types too. The create table in SQL server query is used to create a new table. The basic syntax for creating a new table in SQL is given below.

2. Steps to Create Table in Sql: Example The HR or senior managers ask you to create a table with EMPLOYEE ID, FIRST AND LAST TIME, GENDER, AND EMAIL ID. How to create a table in SQL in this case? Follow the script below. Input Commands CREATE TABLE Employee( E_ID INT PRIMARY KEY, E_Name VARCHAR(25), E_Gender VARCHAR(1), E_Email_Id NVARCHAR(20) UNIQUE; INSERT INTO Employee VALUES (1, 'Samantha', 'M', 'sa.com'); INSERT INTO Employee VALUES (2, 'David', 'M', 'da.com'); INSERT INTO Employee VALUES (3, 'Rachel', 'F', 'ra.com'); INSERT INTO Employee VALUES (4, 'Alice', 'F', 'al.com'); SELECT * FROM Employee; Output So, how does this script work to create a new table and to create a new column SQL? The script will- create a table. It adds three columns and defines data types for each column. It specifies that Status ID is an identity column, and the value of the first column is 1. The value for each subsequent column will automatically increase by 1. It specifies that values in the Status Name column can have a maximum of 50 characters. It specifies that NULL values are not allowed for the column. In the Date Created Column, it sets a default value for the current data and the Status IS field is defined as the primary key.

3. So, this is just a basic script that creates a small table and is quite easy to understand. You can quickly customize this script to run the whole database with its objects, data, and permission all in one go. Besides steps to add column in SQL, when you create database objects, it is a wonderful practice to see whether an object already exists or not. It prevents error and helps in managing redundancy or duplicate entries that ultimately helps in improving the overall performance of a database script. Please Note: Keep in mind that Create table script will work only if the table does not exist in the database. Here is how the script will change in this case. IF NOT EXISTS (SELECT * FROM sysobjects WHERE name='Status' AND xtype='U') You should add this code to your script at the upper end and run the script again. You can also replace an existing table too. For this purpose, you should drop the existing table first and create a new one then. For example: DROP TABLE IF EXISTS [TaskTracker].[Status] Add this code at the starting of the script and use the same script again. It will first drop the existing table and create a new one as per the requirement. Also, Note: It is possible to generate a SQL Script from Object Explorer in the SSMS GUI. With this, SQL generates all the SQL code from the table and creates a table. For this purpose - You just have to right-click on the table and create a script for the same. It is not limited to tables only, but you can generate scripts for database objects as well. Now, that you know how to create a table and a table script in SQL Server Management Studio, it's time to learn how to add columns in SQL. Are you looking for a job as a DBA or Developer? Or are you preparing for an interview or test? Check out the Top 50 DB2 Interview Questions and Answers and crack your next interview with confidence! Final Thoughts You can easily add column in SQL using the ALTER TABLE. Our tricks mentioned above are a complete guide on the same along with real-life examples. Now you must note down these steps somewhere and try implementing them on your own. This will be a holistic learning opportunity for you.

4. However, ALTER TABLE command will be a Child’s Play if you have some background related to it or if you sharpen up your skills with the right certification. Then all these tricks will be easy to practice in real-life cases. Whether you have those credentials or not, our affordable online SQL server training at JanBask Training along with free career consultation will help you learn from scratch to develop commands on database systems. Join our comprehensive SQL Server Certification to be industry-ready!