feat: add custom SQL handling for triggers and virtual tables

- Introduced a new method `runCustomMigrations` in `DbService` to execute custom SQL statements that Drizzle cannot manage, such as triggers and virtual tables.
- Updated `database-patterns.md` and `README.md` to document the handling of custom SQL and its importance in maintaining database integrity during migrations.
- Refactored `messageFts.ts` to define FTS5 virtual table and associated triggers as idempotent SQL statements for better migration management.

docs/en/references/data/database-patterns.md

@@ -197,3 +197,11 @@ return this.getById(id)
 
 The schema supports soft delete via `deletedAt` field (see `createUpdateDeleteTimestamps`).
 Business logic can choose to use soft delete or hard delete based on requirements.
+
+## Custom SQL
+
+Drizzle cannot manage triggers and virtual tables (e.g., FTS5). These are defined in `customSql.ts` and run automatically after every migration.
+
+**Why**: SQLite's `DROP TABLE` removes associated triggers. When Drizzle modifies a table schema, it drops and recreates the table, losing triggers in the process.
+
+**Adding new custom SQL**: Define statements as `string[]` in the relevant schema file, then spread into `CUSTOM_SQL_STATEMENTS` in `customSql.ts`. All statements must use `IF NOT EXISTS` to be idempotent.

migrations/sqlite-drizzle/meta/_journal.json

@@ -9,11 +9,11 @@
       "when": 1767272575118
     },
     {
+      "breakpoints": true,
       "idx": 1,
-      "version": "6",
-      "when": 1767455592181,
       "tag": "0001_futuristic_human_fly",
-      "breakpoints": true
+      "version": "6",
+      "when": 1767455592181
     }
   ],
   "version": "7"

src/main/data/db/DbService.ts

@@ -6,6 +6,7 @@ import { app } from 'electron'
 import path from 'path'
 import { pathToFileURL } from 'url'
 
+import { CUSTOM_SQL_STATEMENTS } from './customSql'
 import Seeding from './seeding'
 import type { DbType } from './types'
 
@@ -120,6 +121,9 @@ class DbService {
       const migrationsFolder = this.getMigrationsFolder()
       await migrate(this.db, { migrationsFolder })
 
+      // Run custom SQL that Drizzle cannot manage (triggers, virtual tables, etc.)
+      await this.runCustomMigrations()
+
       logger.info('Database migration completed successfully')
     } catch (error) {
       logger.error('Database migration failed', error as Error)
@@ -127,6 +131,27 @@ class DbService {
     }
   }
 
+  /**
+   * Run custom SQL statements that Drizzle cannot manage
+   *
+   * This includes triggers, virtual tables, and other SQL objects.
+   * Called after every migration because:
+   * 1. Drizzle doesn't track these in schema
+   * 2. DROP TABLE removes associated triggers
+   * 3. All statements use IF NOT EXISTS, so they're idempotent
+   */
+  private async runCustomMigrations(): Promise<void> {
+    try {
+      for (const statement of CUSTOM_SQL_STATEMENTS) {
+        await this.db.run(sql.raw(statement))
+      }
+      logger.debug('Custom migrations completed', { count: CUSTOM_SQL_STATEMENTS.length })
+    } catch (error) {
+      logger.error('Custom migrations failed', error as Error)
+      throw error
+    }
+  }
+
   /**
    * Get the database instance
    * @throws {Error} If database is not initialized

src/main/data/db/README.md

@@ -14,8 +14,10 @@ src/main/data/db/
 │   ├── columnHelpers.ts  # Reusable column definitions
 │   ├── topic.ts          # Topic table
 │   ├── message.ts        # Message table
+│   ├── messageFts.ts     # FTS5 virtual table & triggers
 │   └── ...               # Other tables
 ├── seeding/              # Database initialization
+├── customSql.ts          # Custom SQL (triggers, virtual tables, etc.)
 └── DbService.ts          # Database connection management
 ```
 
@@ -33,6 +35,10 @@ src/main/data/db/
 yarn db:migrations:generate
 ```
 
+### Custom SQL (Triggers, Virtual Tables)
+
+Drizzle cannot manage triggers and virtual tables. See `customSql.ts` for how these are handled.
+
 ### Column Helpers
 
 ```typescript

src/main/data/db/customSql.ts

@@ -0,0 +1,25 @@
+/**
+ * Custom SQL statements that Drizzle cannot manage
+ *
+ * Drizzle ORM doesn't track:
+ * - Virtual tables (FTS5)
+ * - Triggers
+ * - Custom indexes with expressions
+ *
+ * These are executed after every migration via DbService.runCustomMigrations()
+ * All statements must be idempotent (use IF NOT EXISTS, etc.)
+ *
+ * To add new custom SQL:
+ * 1. Create statements in the relevant schema file (e.g., messageFts.ts)
+ * 2. Import and spread them into CUSTOM_SQL_STATEMENTS below
+ */
+
+import { MESSAGE_FTS_STATEMENTS } from './schemas/messageFts'
+
+/**
+ * All custom SQL statements to run after migrations
+ */
+export const CUSTOM_SQL_STATEMENTS: string[] = [
+  ...MESSAGE_FTS_STATEMENTS
+  // Add more custom SQL arrays here as needed
+]

src/main/data/db/schemas/messageFts.ts

@@ -24,58 +24,50 @@ export const SEARCHABLE_TEXT_EXPRESSION = `
 `
 
 /**
- * Migration SQL - Copy these statements to migration file
+ * Custom SQL statements that Drizzle cannot manage
+ * These are executed after every migration via DbService.runCustomMigrations()
+ *
+ * All statements should use IF NOT EXISTS to be idempotent.
  */
-export const MESSAGE_FTS_MIGRATION_SQL = `
+export const MESSAGE_FTS_STATEMENTS: string[] = [
---> statement-breakpoint
+  // FTS5 virtual table, Links to message table's searchable_text column
--- ============================================================
+  `CREATE VIRTUAL TABLE IF NOT EXISTS message_fts USING fts5(
--- FTS5 Virtual Table and Triggers for Message Full-Text Search
+    searchable_text,
--- ============================================================
+    content='message',
+    content_rowid='rowid',
+    tokenize='trigram'
+  )`,
 
--- 1. Create FTS5 virtual table with external content
+  // Trigger: populate searchable_text and sync FTS on INSERT
---    Links to message table's searchable_text column
+  `CREATE TRIGGER IF NOT EXISTS message_ai AFTER INSERT ON message BEGIN
-CREATE VIRTUAL TABLE IF NOT EXISTS message_fts USING fts5(
+    UPDATE message SET searchable_text = (
-  searchable_text,
+      SELECT group_concat(json_extract(value, '$.content'), ' ')
-  content='message',
+      FROM json_each(json_extract(NEW.data, '$.blocks'))
-  content_rowid='rowid',
+      WHERE json_extract(value, '$.type') = 'main_text'
-  tokenize='trigram'
+    ) WHERE id = NEW.id;
-);--> statement-breakpoint
+    INSERT INTO message_fts(rowid, searchable_text)
+    SELECT rowid, searchable_text FROM message WHERE id = NEW.id;
+  END`,
 
--- 2. Trigger: populate searchable_text and sync FTS on INSERT
+  // Trigger: sync FTS on DELETE
-CREATE TRIGGER IF NOT EXISTS message_ai AFTER INSERT ON message BEGIN
+  `CREATE TRIGGER IF NOT EXISTS message_ad AFTER DELETE ON message BEGIN
-  -- Extract searchable text from data.blocks
+    INSERT INTO message_fts(message_fts, rowid, searchable_text)
-  UPDATE message SET searchable_text = (
+    VALUES ('delete', OLD.rowid, OLD.searchable_text);
-    SELECT group_concat(json_extract(value, '$.content'), ' ')
+  END`,
-    FROM json_each(json_extract(NEW.data, '$.blocks'))
-    WHERE json_extract(value, '$.type') = 'main_text'
-  ) WHERE id = NEW.id;
-  -- Sync to FTS5
-  INSERT INTO message_fts(rowid, searchable_text)
-  SELECT rowid, searchable_text FROM message WHERE id = NEW.id;
-END;--> statement-breakpoint
 
--- 3. Trigger: sync FTS on DELETE
+  // Trigger: update searchable_text and sync FTS on UPDATE OF data
-CREATE TRIGGER IF NOT EXISTS message_ad AFTER DELETE ON message BEGIN
+  `CREATE TRIGGER IF NOT EXISTS message_au AFTER UPDATE OF data ON message BEGIN
-  INSERT INTO message_fts(message_fts, rowid, searchable_text)
+    INSERT INTO message_fts(message_fts, rowid, searchable_text)
-  VALUES ('delete', OLD.rowid, OLD.searchable_text);
+    VALUES ('delete', OLD.rowid, OLD.searchable_text);
-END;--> statement-breakpoint
+    UPDATE message SET searchable_text = (
-
+      SELECT group_concat(json_extract(value, '$.content'), ' ')
--- 4. Trigger: update searchable_text and sync FTS on UPDATE OF data
+      FROM json_each(json_extract(NEW.data, '$.blocks'))
-CREATE TRIGGER IF NOT EXISTS message_au AFTER UPDATE OF data ON message BEGIN
+      WHERE json_extract(value, '$.type') = 'main_text'
-  -- Remove old FTS entry
+    ) WHERE id = NEW.id;
-  INSERT INTO message_fts(message_fts, rowid, searchable_text)
+    INSERT INTO message_fts(rowid, searchable_text)
-  VALUES ('delete', OLD.rowid, OLD.searchable_text);
+    SELECT rowid, searchable_text FROM message WHERE id = NEW.id;
-  -- Update searchable_text
+  END`
-  UPDATE message SET searchable_text = (
+]
-    SELECT group_concat(json_extract(value, '$.content'), ' ')
-    FROM json_each(json_extract(NEW.data, '$.blocks'))
-    WHERE json_extract(value, '$.type') = 'main_text'
-  ) WHERE id = NEW.id;
-  -- Add new FTS entry
-  INSERT INTO message_fts(rowid, searchable_text)
-  SELECT rowid, searchable_text FROM message WHERE id = NEW.id;
-END;
-`
 
 /**
  * Rebuild FTS index (run manually if needed)