SQL Query to Insert Multiple Rows

In SQL, the INSERT statement is used to add new records to a database table. When you need to insert multiple rows in a single query, the INSERT statement becomes efficient.

In this article, We will learn different methods such as using basic INSERT statements, utilizing INSERT INTO ... SELECT for bulk inserts, and handling transactions for larger datasets. Additionally, we will discuss advanced techniques like bulk inserts and optimization tips for efficiently inserting data.

How to Insert Multiple Rows in SQL

Insertion in a table is a DML (Data manipulation language) operation in SQL. When we want to store data we need to insert the data into the database. We use the INSERT statement to insert the data into the database. 
 
Inserting multiple rows can be done in several ways. The most common methods include using a simple INSERT statement with multiple value sets, utilizing the INSERT INTO ... SELECT syntax, and using transactions for batch inserts. Before we dive into these techniques, let’s first create a sample table structure to work with.

Creating a Table: Create a table employee_details with  4 columns using the following SQL query: 

Query:

CREATE TABLE Employees (
    EmployeeID INT PRIMARY KEY,
    EmployeeName VARCHAR(100),
    Age INT,
    Department VARCHAR(50)
);

This table, Employees, will serve as an example for all the insertion methods discussed in this article. It includes four columns: EmployeeID, EmployeeName, Age, and Department.

Basic INSERT for Multiple Rows

The simplest method to insert multiple rows is by using a single INSERT INTO statement followed by multiple sets of values. This approach allows you to insert multiple records in one go, improving efficiency.

Query:

INSERT INTO Employees (EmployeeID, EmployeeName, Age, Department)
VALUES
    (1, 'John Doe', 30, 'Engineering'),
    (2, 'Jane Smith', 28, 'Marketing'),
    (3, 'Sam Brown', 35, 'Sales'),
    (4, 'Lucy Green', 25, 'Human Resources');

Output:

This query inserts four rows into the Employees table. It’s a simple, effective method for adding multiple records at once, and it reduces the need for multiple INSERT statements.

Using INSERT INTO ... SELECT for Inserting Multiple Rows

The INSERT INTO ... SELECT method is useful when you need to insert multiple rows into a table based on the results of another query or a different table. This method is often used for transferring data between tables or inserting derived data into a target table.

NewEmployees table

CREATE TABLE NewEmployees (
    EmployeeID INT PRIMARY KEY,
    EmployeeName VARCHAR(100),
    Age INT,
    Department VARCHAR(50)
);
INSERT INTO NewEmployees (EmployeeID, EmployeeName, Age, Department)
VALUES
    (5, 'Alice Johnson', 29, 'HR'),
    (6, 'Bob Martin', 32, 'Finance'),
    (7, 'Charlie Baker', 28, 'Marketing'),
    (8, 'David Lee', 40, 'Engineering'),
    (9, 'Eva Davis', 22, 'Sales');

Output:

In this example, the INSERT INTO ... SELECT statement copies data from the NewEmployees table to the Employees table, but only inserts those records where the employee’s age is greater than 30.

Query:

INSERT INTO Employees (EmployeeID, EmployeeName, Age, Department)
SELECT EmployeeID, EmployeeName, Age, Department
FROM NewEmployees
WHERE Age > 30;

Output:

Inserting Data Using Transactions

When inserting large amounts of data, you can use SQL transactions to ensure that all rows are inserted correctly. A transaction groups multiple SQL operations into a single unit, so if one operation fails, the entire transaction is rolled back.

Query:

BEGIN TRANSACTION;

    INSERT INTO Customers (CustomerID, CustomerName, ContactName, Country)
    VALUES (5, 'Sarah White', 'John White', 'Canada');
    
    INSERT INTO Customers (CustomerID, CustomerName, ContactName, Country)
    VALUES (6, 'Mohamed Ibrahim', 'Ahmed Ibrahim', 'UAE');
    
    -- If any error occurs, the transaction will be rolled back

COMMIT;

Output:

In this example, the BEGIN TRANSACTION starts the transaction, and the COMMIT command commits the changes to the database. If any INSERT operation fails, the transaction can be rolled back using ROLLBACK to avoid partial data insertion.

Conclusion

Inserting multiple rows in SQL can be done in several ways depending on your use case. Whether you’re using the basic INSERT INTO statement for simple data entry or leveraging advanced techniques like transactions, bulk inserts, and MERGE for complex scenarios, SQL provides powerful tools to efficiently insert large volumes of data.