How to Insert Multiple Rows in SQL

SQL, or Structured Query Language, is a powerful programming language that is used to manage and manipulate relational databases.

One of the most important tasks in working with databases is inserting data, and in this article, we will be discussing how to insert multiple rows in SQL.


How to insert multiple rows in SQL

The first step in understanding how to insert multiple rows in SQL is to understand the basic syntax of the INSERT statement.

The INSERT statement is used to insert a single row of data into a table.

The basic syntax of the INSERT statement is as follows:

INSERT INTO table_name (column1, column2, column3, …)
VALUES (value1, value2, value3, …);

In this syntax, “table_name” is the name of the table where you want to insert the data, and “column1, column2, column3, …” are the names of the columns in the table.

The “VALUES” keyword is used to specify the values for each column.

Now that we understand the basics of the INSERT statement, let’s discuss some techniques for inserting multiple rows in SQL.

Method 1: Using the UNION operator

The UNION operator is a powerful tool that can be used to combine multiple SELECT statements into a single INSERT statement.

The basic syntax of this method is as follows:

INSERT INTO table_name (column1, column2, column3, ...)
SELECT value1, value2, value3, ...
FROM other_table
UNION
SELECT value4, value5, value6, ...
FROM yet_another_table;

In this syntax, “other_table” and “yet_another_table” are the names of the tables from which you want to insert data.

The UNION operator combines the data from these tables and inserts it into the specified table.

One limitation of using this method is that all SELECT statements must have the same number of columns.

Method 2: Using the INSERT INTO SELECT statement

Another technique for inserting multiple rows in SQL is to use the INSERT INTO SELECT statement.

This method allows you to insert data from one table into another. The basic syntax of this method is as follows:

INSERT INTO table_name (column1, column2, column3, ...)
SELECT column1, column2, column3, ...
FROM other_table;

In this syntax, “other_table” is the name of the table from which you want to insert data. The SELECT statement selects the data from this table and inserts it into the specified table.

The advantage of using this method is that it allows you to insert data from multiple tables, making it more flexible than the UNION operator.

Method 3: Using the VALUES keyword

The final technique for inserting multiple rows in SQL is to use the VALUES keyword. This method allows you to insert multiple rows with a single INSERT statement. The basic syntax of this method is as follows:

INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...), (value4, value5, value6, ...), ...;

In this syntax, “value1, value2, value3, …” and “value4, value5, value6, …” are the values for the first and second rows respectively.

The limitation of using this method is that all rows must have the same number of values.

Now that we have discussed the various techniques for inserting multiple rows in SQL, let’s talk about some best practices for working with multiple rows.

One important best practice is to use transactions when inserting multiple rows.

A transaction is a group of SQL statements that are executed together as a single unit of work.

This ensures that all statements in the transaction are executed successfully, or none of them are executed at all.

This is particularly important when inserting multiple rows, as it ensures that the data consistency is maintained even if an error occurs.

Another best practice is to use prepared statements when inserting multiple rows.

Prepared statements are pre-compiled SQL statements that can be executed multiple times with different parameters.

This can improve performance and also helps prevent SQL injection attacks.


Conclusion

In conclusion, inserting multiple rows in SQL is a task that is essential for working with databases.

We have discussed the basic syntax of the INSERT statement, as well as three techniques for inserting multiple rows: using the UNION operator, using the INSERT INTO SELECT statement, and using the VALUES keyword.

We also discussed some best practices for working with multiple rows, such as using transactions and prepared statements.

We hope that this post has been helpful in understanding how to insert multiple rows in SQL.