SQLite 3 C API 事务

I am using SQLite3 for iPhone development and I'm attempting to wrap a few insert statements into a transaction. Currently I have the below code which is working properly however after reading another question on SO I realized it would be better to have these in one transaction rather than one each. I couldn't find the C API call to begin and commit a transaction. Some of the code is in Objective-C but I don't think that's really relevent to the question.

- (void)saveAnimals {
    //Insert all the animals into the zoo database
    int i;

    const char *sql = "insert into Animal(Zoo_ID, Animal_Num, Animal_Text) Values(?, ?, ?)";
    for (i = 0; i < ([[self animalArray] count] - 1); i++) {

        if(addStmt == nil) {
            if(sqlite3_prepare_v2(database, sql, -1, &addStmt, NULL) != SQLITE_OK)
                NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(database));
        }
        int animalNum = [[[self animalArray] objectAtIndex:i] animal_Number];
        NSString *animalText = [[NSString alloc] initWithString:[[[self animalArray] objectAtIndex:i] animal_Text]];
        sqlite3_bind_int(addStmt, 1, zoo_ID);   
        sqlite3_bind_int(addStmt, 2, animalNum);    
        sqlite3_bind_text(addStmt, 3, [animalText UTF8String], -1, SQLITE_TRANSIENT);
        [animalText release];
        if(SQLITE_DONE != sqlite3_step(addStmt)) {
            NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database));
        }

        //Reset the add statement.
        sqlite3_reset(addStmt);     
    }
}

我认为需要做的是将 sqlite3_prepare_v2 命令从 for 循环中取出，启动事务，通过 for 循环，提交事务.但是，我不确定开始交易"和提交交易"的要求是什么.我还会使用 sqlite3_step 吗?感谢您的帮助.