How to Insert Data into a SQL Table

Learning how to insert data into a SQL table is one of the most common tasks for learning to code in SQL. In this article, we will provide a step-by-step guide on how to insert data into a SQL table, along with some examples to help you get started.

Before we begin, it’s important to make sure that you have access to a SQL database and that you know how to connect to it using a SQL client. If you’re not familiar with these concepts, you may want to read up on them before proceeding.

With that said, let’s dive in!

Step 1: Connect to your SQL database

The first step in inserting data into a SQL table is to connect to your SQL database. To do this, you will need to use a SQL client such as MySQL Workbench or pgAdmin.

Once you have your SQL client open, you will need to enter your login credentials to connect to your database. This will typically include your username, password, and the name of the database that you want to connect to.

Once you have successfully connected to your database, you should see a list of all the tables that are available in the database.

Step 2: Select the table you want to insert data into

Next, you will need to select the table that you want to insert data into. To do this, you can either select the table from the list of tables in your database, or you can use the SELECT statement to specify the table that you want to use.

For example, let’s say you have a table called customers and you want to insert data into this table. You could use the following SELECT statement to select the customers table:

SELECT * FROM customers;

This statement will retrieve all of the data from the customers table and display it in your SQL client. We can assume that we have columns for first_name, last_name, and email.

Step 3: Use the INSERT INTO statement to insert data into the table

Now that you have selected the table that you want to insert data into, you can use the INSERT INTO statement to add new rows to the table.

The INSERT INTO statement has the following syntax:

INSERT INTO table_name (column1, column2, ...)
VALUES (value1, value2, ...);

To insert data into the customers table, you could use the following statement:

INSERT INTO customers (first_name, last_name, email)
VALUES ('John', 'Doe', 'john.doe@example.com');

This statement will insert a new row into the customers table, with the values 'John', 'Doe', and 'john.doe@example.com' in the first_name, last_name, and email columns, respectively.

You can insert multiple rows into a table at once by using the INSERT INTO statement multiple times, or by using the INSERT INTO SELECT statement. This statement allows you to insert data into a table by selecting data from another table or query.

For example, let’s say you have another table called users and you want to insert all of the data from this table into the customers table. You could use the following INSERT INTO SELECT statement to do this:

INSERT INTO customers (first_name, last_name, email)
SELECT first_name, last_name, email
FROM users

This code will create a single record in the customers table for each record in the users table and it will populate the column values in customers from the values in users.

Data Types and Insert Statements in SQL

As with all of our data operations in SQL, keep in mind that the data types must match. Inserting a character value into a field defined as numeric will result in an error message. Insert a numeric value into a field defined as character will fail unless you put single quotes around the number and treat it as a string value. Similarly, you must make sure that values inserted into date fields are correct dates.

Those are the most basic steps for inserting data into a SQL table. Happy coding!