Issue Overview: JSON-Based Bulk Update Producing NULL Values Instead of Expected Numbers The core challenge involves attempting to update multiple rows in an SQLite table using values extracted from a JSON array. The table t contains columns f_id (foreign key), t_id (primary key), and amount (numeric value). A JSON object contains an array of objects…
Understanding ALTER TABLE DROP COLUMN Behavior Across SQLite Versions The execution of the ALTER TABLE tablename DROP COLUMN colname statement in SQLite can yield inconsistent results depending on the version of the SQLite3 library in use. A syntax error such as near "DROP": syntax error indicates that the SQL parser does not recognize the DROP…
Understanding Concurrent Insertions and Auto-Incrementing Key Retrieval Challenges SQLite’s auto-incrementing primary key mechanism is widely used to generate unique identifiers for new rows. However, retrieving the correct value of this key in concurrent environments—where multiple application instances or connections may perform simultaneous write operations—requires careful consideration of SQLite’s concurrency model, transaction isolation, and API behavior….
Memory Leaks and Heap-Use-After-Free: An Overview Memory leaks and heap-use-after-free vulnerabilities are critical issues that can compromise the stability, performance, and security of SQLite databases. These vulnerabilities arise when memory allocated during the execution of SQLite operations is not properly released or when previously freed memory is accessed again. The consequences of these issues can…
Understanding SQLite Database Corruption and Recovery Feasibility The "database disk image is malformed" error in SQLite indicates structural corruption within the database file. This error arises when SQLite’s internal consistency checks detect anomalies in the database’s storage format, such as invalid page headers, mismatched cell pointers, or broken b-tree structures. Corruption can occur at various…
Issue Overview: SQLITE_USE_SEH and SQLITE_OMIT_SEH Misconfiguration in MSVC Compilation When compiling SQLite with Microsoft Visual C++ (MSVC) on Windows, developers often encounter issues related to Structured Exception Handling (SEH). SEH is a Microsoft-specific mechanism for handling hardware and software exceptions, and SQLite provides compile-time options to control its usage. The core issue revolves around the…
Understanding the "Specified Procedure Could Not Be Found" Error in SQLite3 Node Module The error message "The specified procedure could not be found" is a common issue encountered when working with native modules in Node.js, particularly in the context of Electron applications. This error typically arises when the application attempts to load a dynamically linked…
Understanding the USE TEMP B-TREE Behavior in Composite Index Queries with ORDER BY and IN Clauses Issue Overview: Composite Index Order Mismatch and Temporary Sorting Overhead The core challenge involves optimizing a SQLite query that selects multiple itemId values with a range condition on eventTs, then orders results by eventTs while avoiding temporary sorting structures….
Understanding the Database Locking Error in SQLite WASM with OPFS and WASMFS When working with SQLite in a WebAssembly (WASM) environment, particularly when using the Origin Private File System (OPFS) and WASMFS, developers may encounter a "database is locked" error. This error typically occurs when attempting to execute a CREATE TABLE statement after opening a…
Issue Overview: Undeclared Function Errors When Compiling SQLite with SQLITE_OMIT_TRIGGER When attempting to build SQLite with the SQLITE_OMIT_TRIGGER compile-time option enabled, developers encounter a series of compilation errors related to undeclared functions. The most prominent error is the failure to recognize the function sqlite3DeleteTriggerStep, which results in the following error message: include/sqlite3.c:174980:1: error: call to…