Objective c 数据库连接代码错误，Xcode 4&；Sqlite3

我不断收到一个错误，上面写着“被调用的NSString类型不是函数或函数指针。我已经尝试了好几天了。我知道我的问题出在哪里了吗

- (void)saveData
{

    sqlite3_stmt    *statement;
    const char *dbpath = [databasePath UTF8String];

    if (sqlite3_open(dbpath, &testdb1) == SQLITE_OK)
    {


        NSString *insertSQL = [NSString stringWithFormat: @"INSERT INTO TESTDB1"
                               (email, username, password, age) VALUES (\"%@\", \"%@\", \"%@\", \"%@\")",
                                email.text, username.text, password.text, age.integer];


        const char *insert_stmt = [insertSQL UTF8String];
        sqlite3_prepare_v2(testdb1, insert_stmt, -1, &statement, NULL);

        if (sqlite3_step(statement) == SQLITE_DONE)
        {
           status.text = @"User added";
           email.text = @"";
           username.text = @"";
           password.text = @"";
           age.text = @"";
        } else {
           status.text = @"Failed to add user";
        }
          sqlite3_finalize(statement);
          sqlite3_close(testdb1);
    }

}

您过早地结束引号；如果仔细观察表达式，您会注意到

@"INSERT INTO TESTDB" (email, username, password, age)

因此，编译器会看到您试图将NSString作为函数调用

NSString *insertSQL = [NSString stringWithFormat: @"INSERT INTO TESTDB1 (email, username, password, age) VALUES (\"%@\", \"%@\", \"%@\", \"%@\")",
                    email.text, username.text, password.text, age.integer];

你应该可以走了

---

附言：在发布您的问题之前，一定要看一看预览版——它的格式非常糟糕。

您在stringWithFormat调用的第二行开头缺少一个引号

NSString *insertSQL = [NSString stringWithFormat: @"INSERT INTO TESTDB1 (email, username, password, age) VALUES (\"%@\", \"%@\", \"%@\", \"%@\")",
                    email.text, username.text, password.text, age.integer];