How to Efficiently Insert Multiple Rows in SQLite?

SQLite multi-row insertion: syntax differences and solutions

In SQL databases, it is a very common requirement to insert multiple rows of data at one time. However, SQLite's implementation is different from MySQL. This article will explore this syntax difference and provide practical solutions for implementing multi-row insertion in SQLite.

Comparison with MySQL syntax

In MySQL, multiple rows can be easily inserted using the following syntax:

<code class="language-sql">INSERT INTO 'tablename' ('column1', 'column2') VALUES
('data1', 'data2'),
('data1', 'data2'),
('data1', 'data2'),
('data1', 'data2');</code>

Alternatives to SQLite

SQLite requires a different approach. It does not use the VALUES clause directly, instead you must use multiple SELECT statements and combine them through the UNION ALL structure to insert rows:

<code class="language-sql">INSERT INTO 'tablename'
SELECT 'data1' AS 'column1', 'data2' AS 'column2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2';</code>

Performance Considerations

While this approach allows multiple rows to be inserted in SQLite, it is worth considering its performance implications. Some users report that it may be more efficient to include a single INSERT statement within a transaction:

<code class="language-sql">BEGIN TRANSACTION;
INSERT INTO 'tablename' VALUES ('data1', 'data2');
INSERT INTO 'tablename' VALUES ('data3', 'data4');
...
COMMIT;</code>

UNION and UNION ALL

When using UNION ALL syntax, all rows will be inserted, which will result in duplicate data if data exists in multiple SELECT statements. To eliminate duplicates, use UNION instead of UNION ALL.

Summary

Inserting multiple rows of data in SQLite requires a different syntax compared to MySQL. The UNION ALL structure allows efficient data insertion while taking into account potential performance impacts. Understanding this syntax difference ensures seamless row insertion operations in a SQLite database.

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