Adventures in Machine Learning

Efficiently Inserting Multiple Rows Using SQL Server: Syntax and Examples

Inserting Multiple Rows Using SQL Server INSERT Statement

SQL Server is a database management system that provides several ways of inserting multiple rows into tables. In this article, we’ll discuss the syntax for inserting multiple rows using the INSERT statement, as well as the limitations and workarounds.

We’ll also demonstrate how to insert multiple rows returned from a SELECT statement.

1. Syntax for inserting multiple rows using INSERT statement

1.1 The syntax for inserting multiple rows using the INSERT statement is as follows:

INSERT INTO table_name (column1, column2, column3, ...)
VALUES
    (value1, value2, value3, ...),
    (value4, value5, value6, ...),
    (value7, value8, value9, ...),
    ...

The first line specifies the table name and the columns that the data will be inserted into.

The second line comprises multiple rows of values, each enclosed in parentheses and separated by commas. Make sure that the number and order of the values correspond to the columns specified in the first line.

For example, to insert three rows of data into the sales.promotions table with the columns promotion_id, promotion_name, and start_date, you can use the following SQL code:

INSERT INTO sales.promotions (promotion_id, promotion_name, start_date)
VALUES
    (1, 'Summer Sale', '2022-06-01'),
    (2, 'Back to School', '2022-08-01'),
    (3, 'Holiday Specials', '2022-12-01');

1.2 You can also use a subquery as a source of the values to be inserted:

INSERT INTO sales.promotions (promotion_id, promotion_name, start_date)
SELECT promotion_id, promotion_name, start_date
FROM staging.promotions;

This code inserts into the sales.promotions table the rows returned by the SELECT statement, which retrieves data from the staging.promotions table.

2. Limitations of inserting multiple rows using INSERT statement

While the INSERT statement is a convenient way of inserting data into a table, it has some limitations when it comes to inserting multiple rows:

  • The number of rows that you can insert at once depends on the database server’s memory and disk space.
  • You may need to split your data into multiple INSERT statements if you’re inserting more than a few thousand rows.
  • Inserting a large number of rows using multiple INSERT statements can be slow and prone to errors. To speed up the process, you can use the BULK INSERT command or a derived table instead.
  • When using the VALUES clause, it can be tedious to specify the same column names and data types repeatedly. You may want to consider using a temporary or staging table to contain your data first, then inserting it into the actual table.

3. Inserting multiple rows returned from a SELECT statement

You can use the INSERT INTO SELECT statement to insert multiple rows returned from a SELECT statement. The syntax is as follows:

INSERT INTO table_name (column1, column2, column3, ...)
SELECT column1, column2, column3, ...
FROM source_table
WHERE condition;

This code retrieves data from the source_table and inserts it into the specified table, using the same column names and data types. For example, to insert all active promotions from the staging.promotions table into the sales.promotions table, you can use the following code:

INSERT INTO sales.promotions (promotion_id, promotion_name, start_date)
SELECT promotion_id, promotion_name, start_date
FROM staging.promotions
WHERE is_active = 1;

This code inserts into the sales.promotions table the rows returned by the SELECT statement, which selects only the promotions that are currently active. Example: SQL Server INSERT Multiple Rows

4. Inserting multiple rows example

Suppose we want to add a few cities to the cities table. We can use the INSERT INTO VALUES statement and provide the values for each column. The code would look like this:

INSERT INTO cities (city_name, country_code, population)
VALUES
    ('San Francisco', 'USA', 883305),
    ('Toronto', 'CAN', 2930000),
    ('Barcelona', 'ESP', 1620343),
    ('Mumbai', 'IND', 20000000),
    ('Tokyo', 'JPN', 37977000);

This code inserts five rows into the cities table with the specified values for city_name, country_code, and population. Note that the order of the values corresponds to the order of the columns in the INSERT INTO statement.

Also, make sure that the values you provide match the data type of the corresponding column.

5. Inserting multiple rows and returning the inserted id list example

Suppose we want to add a few promotions to the sales.promotions table and retrieve the list of promotion_ids that were inserted. We can use the OUTPUT clause to specify the columns to be returned and the inserted table to access the list.

5.1 The code would look like this:

DECLARE @inserted_ids TABLE (promotion_id INT);
INSERT INTO sales.promotions (promotion_name, start_date, end_date)
OUTPUT inserted.promotion_id INTO @inserted_ids
VALUES
    ('Summer Sale', '2022-06-01', '2022-06-30'),
    ('Back to School', '2022-08-01', '2022-09-15'),
    ('Holiday Specials', '2022-12-01', '2023-01-02');

SELECT promotion_id
FROM @inserted_ids;

This code inserts three rows into the sales.promotions table with the specified values for promotion_name, start_date, and end_date. The OUTPUT clause captures the inserted promotion_ids and stores them in a table variable @inserted_ids.

Finally, the SELECT statement retrieves the promotion_ids from the table variable. Note that you need to declare the table variable first with the appropriate column(s) and data type(s).

6. Conclusion

In this article, we’ve introduced the syntax for inserting multiple rows using the SQL Server INSERT statement and discussed its limitations and workarounds. We’ve also demonstrated how to insert multiple rows returned from a SELECT statement, as well as how to retrieve the inserted id list.

We hope this article has helped you understand how to efficiently insert data into SQL Server tables. Happy coding!

In summary, this article has provided an overview of inserting multiple rows using SQL Server INSERT statement and discussed its syntax, limitations, and workarounds.

We’ve also demonstrated how to insert multiple rows returned from a SELECT statement and retrieve the inserted id list. It’s important to efficiently and accurately insert data into SQL Server tables, and we hope this article has provided valuable insights for achieving this.

Takeaways include understanding the syntax for inserting multiple rows, being aware of limitations and potential workarounds, and utilizing the appropriate statement for inserting rows returned from a SELECT statement. In conclusion, mastering this topic is essential for efficient database management and data analysis.

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