On Android, allow PRAGMA statements that assign when invoked via exec

android/src/main/java/dog/craftz/sqlite_2/RNSqlite2Module.java

@@ -87,8 +87,10 @@ public void run() {
             String sql = sqlQuery.getString(0);
             ReadableArray queryArgs = sqlQuery.getArray(1);
             try {
-              if (isSelectOrPragmaQuery(sql)) {
+              if (isSelectQuery(sql)) {
                 results[i] = doSelectInBackgroundAndPossiblyThrow(sql, queryArgs, db);
+              } else if (isPragmaQuery(sql)) {
+                results[i] = doPragmaInBackgroundAndPossiblyThrow(sql, queryArgs, db);
               } else { // update/insert/delete
                 if (readOnly) {
                   results[i] = new SQLitePLuginResult(EMPTY_ROWS, EMPTY_COLUMNS, 0, 0, new ReadOnlyException());
@@ -165,6 +167,35 @@ private SQLitePLuginResult doUpdateInBackgroundAndPossiblyThrow(String sql, Read
     }
   }
 
+  private SQLitePLuginResult doPragmaInBackgroundAndPossiblyThrow(String sql, ReadableArray queryArgs, SQLiteDatabase db) {
+    debug("\"all\" query: %s", sql);
+    Cursor cursor = null;
+    try {
+      String[] bindArgs = convertParamsToStringArray(queryArgs);
+      cursor = db.rawQuery(sql, bindArgs);
+      int numRows = cursor.getCount();
+      if (numRows == 0) {
+        return EMPTY_RESULT;
+      }
+      int numColumns = cursor.getColumnCount();
+      Object[][] rows = new Object[numRows][];
+      String[] columnNames = cursor.getColumnNames();
+      for (int i = 0; cursor.moveToNext(); i++) {
+        Object[] row = new Object[numColumns];
+        for (int j = 0; j < numColumns; j++) {
+          row[j] = getValueFromCursor(cursor, j, cursor.getType(j));
+        }
+        rows[i] = row;
+      }
+      debug("returning %d rows", numRows);
+      return new SQLitePLuginResult(rows, columnNames, 0, 0, null);
+    } finally {
+      if (cursor != null) {
+        cursor.close();
+      }
+    }
+  }
+
   // do a select operation
   private SQLitePLuginResult doSelectInBackgroundAndPossiblyThrow(String sql, ReadableArray queryArgs, SQLiteDatabase db) {
     debug("\"all\" query: %s", sql);
@@ -286,9 +317,11 @@ private static WritableNativeArray convertPluginResultToArray(SQLitePLuginResult
   }
 
 
-  private static boolean isSelectOrPragmaQuery(String str) {
-    return startsWithCaseInsensitive(str, "select") ||
-            (startsWithCaseInsensitive(str, "pragma") && !str.contains("="));
+  private static boolean isSelectQuery(String str) {
+    return startsWithCaseInsensitive(str, "select");
+  }
+  private static boolean isPragmaQuery(String str) {
+    return startsWithCaseInsensitive(str, "pragma");
   }
   private static boolean isInsert(String str) {
     return startsWithCaseInsensitive(str, "insert");

test/app.js

@@ -10,12 +10,23 @@ import {
 
 import SQLite from 'react-native-sqlite-2'
 
+function databaseName(name) {
+  return name + '.' + Math.floor(Math.random() * 100000)
+}
+
 const database_name = 'test.db'
 const database_version = '1.0'
 const database_displayname = 'SQLite Test Database'
 const database_size = 200000
 let db
 
+function exposedPromise() {
+  let resolveLoading
+  const p = new Promise((resolve) => (resolveLoading = resolve))
+  p.resolve = resolveLoading
+  return p
+}
+
 export default class ReactNativeSQLite2Test extends Component {
   constructor(props) {
     super(props)
@@ -67,7 +78,65 @@ export default class ReactNativeSQLite2Test extends Component {
     this.addLog('Database DELETED')
   }
 
-  populateDatabase(db) {
+  assigningPragma(db) {
+    new Promise((resolve) => {
+      let sql = "PRAGMA journal_mode = WAL"
+      db._db.exec([{sql: sql, args: []}], false, (_, result) => {
+        let journal_mode = result[0].rows[0].journal_mode
+        if (journal_mode == "wal") {
+          this.addLog("✅ " + sql)
+        } else {
+          this.addLog("❌ " + sql)
+          console.log(result, journal_mode)
+        }
+        resolve()
+      })
+    })
+  }
+
+  queryingPragma(db, isWal) {
+    new Promise((resolve) => {
+      let sql = "PRAGMA journal_mode"
+      db._db.exec([{sql: sql, args: []}], false, (_, result) => {
+        journal_mode = result[0].rows[0].journal_mode
+        // Default journal_modes differ on Android & iOS
+        if (!isWal && journal_mode != "wal" ||
+            isWal && journal_mode == "wal") {
+          this.addLog("✅ " + sql)
+        } else {
+          this.addLog("❌ " + sql)
+          console.log(result, journal_mode)
+        }
+        resolve()
+      })
+    })
+  }
+
+  buildPragmaSchema(db) {
+    new Promise((resolve) => {
+      db._db.exec([{sql: "CREATE TABLE Version(version_id INTEGER PRIMARY KEY NOT NULL);", args: []}], false, (_, result) => {
+        resolve()
+      })
+    })
+  }
+
+  assigningParenthesisPragma(db) {
+    new Promise((resolve) => {
+      let sql = "PRAGMA main.wal_checkpoint(FULL)"
+      db._db.exec([{sql: sql, args: []}], false, (_, result) => {
+        row = result[0].rows[0]
+        if (row.busy == 0 && row.checkpointed != -1 && row.log != -1) {
+          this.addLog("✅ " + sql)
+        } else {
+          this.addLog("❌ " + sql)
+          console.log(result, row)
+        }
+        resolve()
+      })
+    })
+  }
+
+  populateDatabase(db, p) {
     this.addLog('Database integrity check')
     const prepareDB = () => {
       db.transaction(this.populateDB, this.errorCB, () => {
@@ -77,6 +146,7 @@ export default class ReactNativeSQLite2Test extends Component {
           this.addLog('Processing completed.')
           db.transaction(this.cleanupTables, this.errorCB, () => {
             this.closeDatabase()
+            p.resolve()
           })
         })
       })
@@ -243,7 +313,7 @@ export default class ReactNativeSQLite2Test extends Component {
     tx.executeSql('DROP TABLE IF EXISTS Departments;')
   }
 
-  loadAndQueryDB() {
+  async loadAndQueryDB() {
     this.addLog('Opening database ...')
     db = SQLite.openDatabase(
       database_name,
@@ -253,7 +323,26 @@ export default class ReactNativeSQLite2Test extends Component {
       this.openCB,
       this.errorCB
     )
-    this.populateDatabase(db)
+    const p = exposedPromise()
+    this.populateDatabase(db, p)
+    await p
+  }
+
+  async pragmaTests() {
+    this.addLog('Open separate DB and run PRAGMA tests')
+    db = SQLite.openDatabase(
+      databaseName(database_name),
+      database_version,
+      database_displayname,
+      database_size,
+      this.openCB,
+      this.errorCB
+    )
+    await this.queryingPragma(db, false)
+    await this.assigningPragma(db)
+    await this.queryingPragma(db, true)
+    await this.buildPragmaSchema(db)
+    await this.assigningParenthesisPragma(db)
   }
 
   closeDatabase = () => {
@@ -264,11 +353,12 @@ export default class ReactNativeSQLite2Test extends Component {
     }
   }
 
-  runDemo() {
+  async runDemo() {
     this.setState({
       progress: ['Starting SQLite Callback Demo']
     })
-    this.loadAndQueryDB()
+    await this.loadAndQueryDB()
+    this.pragmaTests();
   }
 
   renderProgressEntry = entry => {