Issue Overview: Named Parameter Handling in SQLite3 WASM The handling of named parameters in SQLite3 WASM has been identified as a source of confusion and potential errors, particularly when interfacing with JavaScript. The core issues revolve around the behavior of the bind() method when dealing with named parameters in SQL queries. Specifically, the problems can…
Virtual Table Corruption in FTS5 Contentless Tables During Trigger-Driven Updates Issue Overview: Malformed Disk Image Due to FTS5 Trigger Interactions The core problem arises when a trigger modifies an FTS5 virtual table (configured as a contentless table) during an INSERT … ON CONFLICT DO UPDATE operation. The trigger attempts to delete a non-existent row from…
Understanding Foreign Key Enforcement During Schema Modifications The core issue arises when attempting to modify a table schema (e.g., adding a column) using graphical tools such as DB Browser for SQLite (DB4S), resulting in the error "Error checking foreign keys after table modification. The changes will be reverted." This error does not occur when performing…
Understanding SQLite WAL Mode Shared Memory Allocation and File Dependencies Issue Overview: SHM File Mapping in WAL Mode and Unexpected SQLITE_CANTOPEN Errors SQLite’s Write-Ahead Logging (WAL) mode introduces a specialized architecture for managing concurrent read/write operations. Central to this architecture is the use of shared memory (SHM) to coordinate access between database connections. The SHM…
Trigger Invocation Order and Determinism in SQLite Issue Overview In SQLite, triggers are powerful tools that allow developers to automate actions in response to specific database events such as INSERT, UPDATE, or DELETE operations. However, when multiple triggers are defined on the same table with similar conditions, questions arise about the order in which these…
Identifying and Safely Removing Dynamic Tables in a Transactional SQLite Database Issue Overview: Managing Dynamic Table Deletion with a Static Retention Requirement In enterprise applications leveraging SQLite on Android devices, a common operational requirement involves maintaining a static table (e.g., Security) within a transactional database (e.g., Daily_Activities) while programmatically purging all dynamically created tables (e.g.,…
Understanding the UNIQUE Constraint Failure in Geopoly’s _shape Column The core issue revolves around the inability to insert multiple records into a SQLite Geopoly table when these records share the same geographic location. This problem manifests as a SqliteError: UNIQUE constraint failed: materialCitationsGeopoly._shape, indicating that the _shape column, which is inherently tied to the Geopoly…
Understanding the Assertion Failure in sqlite3WhereEnd with Indexed Generated Columns Root Cause: Query Planner Misoptimization Involving Index-Only Scans on Generated Columns The core issue arises when SQLite’s query planner attempts to optimize a query that combines generated columns, indexed expressions, and correlated subqueries. Specifically, the assertion failure occurs in the sqlite3WhereEnd function during the finalization…
Understanding the Expression Parsing Failure in Collation-Sensitive Indexed Queries Issue Overview This guide addresses an assertion failure triggered during SQLite query execution involving collation-aware indexed expressions. The failure occurs in the sqlite3ExprSkipCollateAndLikely function when the parser encounters an expression node that does not match the expected TK_COLLATE operation type. The problem manifests specifically in scenarios…
Issue Overview: Query Planner Fails to Use Indexes on UNION ALL Views and Multi-Table Joins A critical performance regression was observed in SQLite versions 3.40.2 and 3.41.x when executing queries involving UNION ALL views built from indexed tables or multi-table joins with complex conditions. The regression manifests as full table scans instead of index-driven lookups,…