Finish transaction implementation for SQLite.

Author: vnayar

source/ddbc/drivers/pgsqlddbc.d

@@ -223,10 +223,10 @@ version(USE_PGSQL) {
 		bool autocommit = true;
         bool useSsl = true;
     	Mutex mutex;
-    	
-    	
+
+
     	PGSQLStatement [] activeStatements;
-    	
+
     	void closeUnclosedStatements() {
     		PGSQLStatement [] list = activeStatements.dup;
     		foreach(stmt; list) {
@@ -331,15 +331,17 @@ version(USE_PGSQL) {
 
     	override void commit() {
     		checkClosed();
-    		
+
     		lock();
     		scope(exit) unlock();
-    		
+
     		Statement stmt = createStatement();
     		scope(exit) stmt.close();
     		stmt.executeUpdate("COMMIT");
             if (!autocommit) {
-              stmt.executeUpdate("BEGIN");
+                Statement stmt2 = createStatement();
+                scope(exit) stmt2.close();
+                stmt2.executeUpdate("BEGIN");
             }
     	}
 
@@ -388,18 +390,18 @@ version(USE_PGSQL) {
     	override bool isClosed() {
     		return closed;
     	}
-    	
+
     	override void rollback() {
     		checkClosed();
-    		
+
     		lock();
     		scope(exit) unlock();
-    		
+
     		Statement stmt = createStatement();
     		scope(exit) stmt.close();
     		stmt.executeUpdate("ROLLBACK");
             if (!autocommit) {
-              stmt.executeUpdate("BEGIN");
+                stmt.executeUpdate("BEGIN");
             }
     	}
     	override bool getAutoCommit() {

source/ddbc/drivers/sqliteddbc.d

@@ -246,11 +246,9 @@ version(USE_SQLITE) {
     class SQLITEConnection : ddbc.core.Connection {
     private:
         string filename;
-
         sqlite3 * conn;
-
         bool closed;
-        bool autocommit;
+        bool autocommit = true;
         Mutex mutex;
 
 
@@ -324,7 +322,8 @@ version(USE_SQLITE) {
 
         override void commit() {
             checkClosed();
-
+            if (autocommit)
+                return;
             lock();
             scope(exit) unlock();
 
@@ -378,14 +377,20 @@ version(USE_SQLITE) {
 
         override void rollback() {
             checkClosed();
-
+            if (autocommit)
+                return;
             lock();
             scope(exit) unlock();
 
             Statement stmt = createStatement();
             scope(exit) stmt.close();
-            //TODO:
-            //stmt.executeUpdate("ROLLBACK");
+
+            stmt.executeUpdate("ROLLBACK");
+            if (!autocommit) {
+                Statement stmt2 = createStatement();
+                scope(exit) stmt2.close();
+                stmt2.executeUpdate("BEGIN");
+            }
         }
         override bool getAutoCommit() {
             return autocommit;
@@ -399,9 +404,11 @@ version(USE_SQLITE) {
 
             Statement stmt = createStatement();
             scope(exit) stmt.close();
-            // autocommit cannot be generally disabled in Sqlite3, thus disable it
-            // by always starting a transaction with the "BEGIN" command.
-            if (autoCommit == false) {
+            if (autoCommit) {
+                // If switching on autocommit, commit any ongoing transaction.
+                stmt.executeUpdate("COMMIT");
+            } else {
+                // If switching off autocommit, start a transaction.
                 stmt.executeUpdate("BEGIN");
             }
             this.autocommit = autoCommit;

test/ddbctest/main.d

@@ -680,7 +680,84 @@ class SQLitePodTest : DdbcTestFixture {
     }
 }
 
+// Test parts of the interfaces related to transactions.
+class SQLiteTransactionTest : DdbcTestFixture {
+    mixin UnitTest;
+
+    this() {
+        super(
+                "sqlite::memory:",
+                "CREATE TABLE records (id SERIAL PRIMARY KEY, name VARCHAR(255) NOT NULL)",
+                "DROP TABLE IF EXISTS records");
+    }
 
+    @Test
+    public void testAutocommitOn() {
+        // This is the default state, it is merely made explicit here.
+        conn.setAutoCommit(true);
+        Statement stmt = conn.createStatement();
+        scope(exit) stmt.close();
+
+        stmt.executeUpdate(`INSERT INTO records (name) VALUES ('Bob')`);
+        conn.rollback();
+        stmt.executeUpdate(`INSERT INTO records (name) VALUES ('Jim')`);
+        conn.commit();
+
+        ddbc.core.ResultSet resultSet;
+        resultSet = stmt.executeQuery(`SELECT * FROM records WHERE name = 'Bob'`);
+        assert(resultSet.next());
+        resultSet = stmt.executeQuery(`SELECT * FROM records WHERE name = 'Jim'`);
+        assert(resultSet.next());
+    }
+
+    @Test
+    public void testAutocommitOff() {
+        // With autocommit set to false, transactions must be explicitly committed.
+        conn.setAutoCommit(false);
+        conn.setAutoCommit(false);  // Duplicate calls should not cause errors.
+        Statement stmt = conn.createStatement();
+        scope(exit) stmt.close();
+
+        stmt.executeUpdate(`INSERT INTO records (name) VALUES ('Greg')`);
+        conn.rollback();
+        stmt.executeUpdate(`INSERT INTO records (name) VALUES ('Tom')`);
+        conn.commit();
+
+        ddbc.core.ResultSet resultSet;
+        resultSet = stmt.executeQuery(`SELECT * FROM records WHERE name = 'Greg'`);
+        assert(!resultSet.next());
+        resultSet = stmt.executeQuery(`SELECT * FROM records WHERE name = 'Tom'`);
+        assert(resultSet.next());
+    }
+
+    @Test
+    public void testAutocommitOffOn() {
+        // A test with a user changing autocommit in between statements.
+        conn.setAutoCommit(false);
+        Statement stmt = conn.createStatement();
+        scope(exit) stmt.close();
+
+        stmt.executeUpdate(`INSERT INTO records (name) VALUES ('Abe')`);
+        conn.setAutoCommit(true);
+        stmt.executeUpdate(`INSERT INTO records (name) VALUES ('Bart')`);
+
+        ddbc.core.ResultSet resultSet;
+        resultSet = stmt.executeQuery(`SELECT * FROM records WHERE name = 'Abe'`);
+        assert(resultSet.next());
+        resultSet = stmt.executeQuery(`SELECT * FROM records WHERE name = 'Bart'`);
+        assert(resultSet.next());
+    }
+
+    @Test
+    public void testTransactionIsolation() {
+        // Setting isolation level is only effective in transactions.
+        conn.setAutoCommit(false);
+        // In SQLite, SERIALIZABLE is the default and not settable.
+        assert(conn.getTransactionIsolation() == TransactionIsolation.SERIALIZABLE);
+        conn.setTransactionIsolation(TransactionIsolation.REPEATABLE_READ);
+        assert(conn.getTransactionIsolation() == TransactionIsolation.SERIALIZABLE);
+    }
+}
 
 // either use the 'Main' mixin or call 'dunit_main(args)'
 mixin Main;