SQLite Query Tracing Without Application Source Access SQLite is a lightweight, serverless, and embedded database engine that operates within the application process itself. This design choice makes it highly efficient but also poses challenges when attempting to trace or log SQL queries executed by an external application, especially when the source code of that application…
Storing and Retrieving Binary Data in SQLite Using BLOBs When working with SQLite in a C program, one common requirement is the storage and retrieval of binary data, such as images, using Binary Large Objects (BLOBs). BLOBs allow for the storage of raw binary data directly within the database, which can be particularly useful for…
Dynamic Pivot Query Requirements in SQLite SQLite, being a lightweight and versatile database engine, is often used for applications requiring dynamic data handling. However, one of the challenges that developers frequently encounter is the need to create pivot queries where the number of resulting columns is not known in advance. This situation arises when the…
Multi-Column Foreign Key Validation Failure Due to Hard-Coded Column In SQLite, foreign key constraints are a powerful mechanism to enforce referential integrity between tables. However, when dealing with multi-column foreign keys, especially those involving a hard-coded column value, unexpected behavior can arise. The core issue here revolves around the validation of foreign key constraints when…
SQLite Multi-Database Transactions and Read-Only Connections In a multi-threaded application where multiple SQLite databases are shared among threads, each thread may own a single database for writing while attaching other databases for read-only access. This setup can lead to complex transaction management, especially when multiple threads interact with the same database files under different connection…
SQLite Foreign Key Constraints: Connection-Level Configuration SQLite is a lightweight, serverless, and self-contained database engine that is widely used in embedded systems, mobile applications, and small-scale projects. One of its features is the support for foreign key constraints, which enforce referential integrity between tables. However, unlike many other database systems, SQLite does not enable foreign…
FTS5 Highlight Function Errors Due to Incorrect Content and Content_Rowid Usage When working with SQLite’s Full-Text Search version 5 (FTS5), one of the most powerful features is the ability to highlight search terms within the retrieved text. However, this functionality can sometimes lead to confusing errors, particularly when the highlight function is used incorrectly or…
Understanding the Challenge of Deleting Unreferenced Rows in Parent Tables In SQLite, managing relationships between parent and child tables is a common task, especially when dealing with foreign key constraints. One of the challenges that arise is the need to delete rows from a parent table that are no longer referenced by any child tables….
Full Table Scans Due to Substring Searches with LIKE ‘%pattern%’ When dealing with a large SQLite database table, such as the logs table containing 522 million records, performance issues often arise when executing queries that involve substring searches using the LIKE operator with wildcards on both sides of the pattern (e.g., LIKE ‘%andy%’). This type…
BLOB Length Calculation Yields Characters Instead of Bytes The core issue revolves around the behavior of the length() function in SQLite when applied to BLOB (Binary Large Object) data. According to the SQLite documentation, the length(X) function should return the number of bytes in a BLOB value X. However, in practice, when a BLOB contains…