Category: SQLite

How to Create a Unique Index in SQLite

Posted on by Ian

SQLite is a lightweight, serverless SQL database engine commonly used for developing mobile applications, web applications, and embedded systems. Among its various functionalities, SQLite allows developers to create indexes, including unique indexes, to enhance data retrieval speed and enforce constraints on data integrity.

A unique index ensures that all values in a specific column, or combination of columns, are distinct, preventing duplicate entries.

In this guide, we’ll walk through the basics of unique indexes in SQLite, explore when and why to use them, and provide examples of how to create them.

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Understanding Type Affinity in SQLite

Posted on by Ian

SQLite is a lightweight, self-contained database engine renowned for its simplicity and flexibility. One of its unique features is the way it handles data types through type affinity, which determines how SQLite associates values with storage classes.

Unlike many database systems that enforce strict type constraints, SQLite’s type affinity system is more flexible, accommodating a broader range of data.

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How to Create a Partial Index in SQLite

Posted on by Ian

Partial indexing is a feature in many DBMSs, including SQLite, that allows developers to optimize database performance by creating indexes only for specific subsets of data. This can significantly reduce the index size and improve query speed, especially in cases where only a portion of the data is frequently queried.

In this article, we’ll look at how to create a partial index in SQLite, why it’s useful, and provide an example to illustrate its use.

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Understanding SQLite’s CAST() Expression

Posted on by Ian

SQLite is a widely-used lightweight database engine that powers many mobile, embedded, and desktop applications. One of its key features is its dynamic type system, which allows flexibility in handling data. While this is advantageous in many scenarios, there are cases where developers need precise control over how data is treated or converted between types. This is where SQLite’s CAST() expression comes in.

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Fix Error “AUTOINCREMENT not allowed on WITHOUT ROWID tables” in SQLite

Posted on by Ian

If you’re getting an error that reads “AUTOINCREMENT not allowed on WITHOUT ROWID tables” in SQLite, it appears that you’re trying to define a column as an AUTOINCREMENT in a WITHOUT ROWID table.

SQLite doesn’t allow us to create AUTOINCREMENT columns on WITHOUT ROWID tables.

To address this issue, either remove the AUTOINCREMENT attribute or remove the WITHOUT ROWID from the table definition.

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An Introduction to SQLite’s LIKELY() Function

Posted on by Ian

SQLite provides a range of tools to help optimize query execution. One of these is the likely() function, which helps developers guide the query planner by hinting at the probability of certain conditions being true.

In this article, we’ll look at the likely() function, understanding how it works, its syntax, some use cases, and its impact on query performance.

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