数据库SQLITE + Unity中的现有数据

Question

我需要在数据库中检查当前值是否存在。但我不知道如何在我的值public Text CreateUsername中使用数据。

    [SerializeField]
    private Text CreateUsername;

创建用户查询

public void CreateUser(string username, int status)
          {
              using (IDbConnection dbConnection = new SqliteConnection(Connection))
              {
                  dbConnection.Open();

                  using (IDbCommand dbCmd = dbConnection.CreateCommand())
                  {
                      string insertuser = String.Format("insert into user_data (UserData_name, UserData_status) values (\"{0}\",\"{1}\")", username, status);

                      dbCmd.CommandText = insertuser;
                      dbCmd.ExecuteScalar();
                      dbConnection.Close();
                  }
              }
          }

插入用户查询...在此过程中，我不知道在字符串checkusername中的什么条件下使用什么正确的查询。

public void insertCreateUser()
    {
        using (IDbConnection dbConnection = new SqliteConnection(Connection))
        {
            dbConnection.Open();

            using (IDbCommand dbCmd = dbConnection.CreateCommand())
            {
                string checkusername = "select count(UserData_name) from user_data where UserData_name ";

                dbCmd.CommandText = updatestatus;
                dbCmd.ExecuteScalar();
                dbConnection.Close();
            }
        }
              ChangeStatus();
              int stat = 1;
              CreateUser(CreateUsername.text, stat);
    }