Web API 查询 SQL 服务器和 return 结果未按预期工作

Question

我正在尝试从 Web API 和 return 连接到 SQL 服务器，结果集为 JSON。但是我在这里显示的代码没有按预期工作。我正在尝试 return 整个查询响应作为 JSON:

[HttpGet]
public HttpResponseMessage Getdetails(string ROOM)
{
    string commandText = "SELECT * from [TDB].[dbo].[results_vw] where ROOM = @ROOM_Data";

    string connStr = ConfigurationManager.ConnectionStrings["TDBConnection"].ConnectionString;

    var jsonResult = new StringBuilder();

    using (SqlConnection connection = new SqlConnection(connStr))
    {
        SqlCommand command = new SqlCommand(commandText, connection);
        command.Parameters.Add("@ROOM_Data", SqlDbType.VarChar);
        command.Parameters["@ROOM_Data"].Value = ROOM;

        connection.Open();

        var reader = command.ExecuteReader();

        if (!reader.HasRows)
        {
            jsonResult.Append("[]");
        }
        else
        {
            while (reader.Read())
            {
                jsonResult.Append(reader.GetValue(0).ToString());
            }
        }

        var response = new HttpResponseMessage(System.Net.HttpStatusCode.OK);
        response.Content = new StringContent(jsonResult.ToString());

        connection.Close();

        return response;
    }
}

此代码 return 此结果：

333838362692368203368203368203362692368203359544362692368203362692368203362692368203368203

我期望 JSON 为

 {"data":
  [
  {"R_ID":"368203","ROOM":"K2"}, 
  {"R_ID":"368203","ROOM":"K2"}
  ]}

现在我创建了一个名为 DatabaseResult 的模型 class 来存储响应，但我不确定如何将结果存储到控制器中的模型 class

public class DatabaseResult
{
      public int r_id { get; set; }
      public string room { get; set; }
}

Answer 1

当前结果是因为您只是return每行第一列的值并将其添加到字符串生成器。

创建模型的新实例并使用来自 reader 的值填充每一行。

[HttpGet]
public IHttpActionResult Getdetails(string ROOM) {
    string commandText = "SELECT * from [TDB].[dbo].[results_vw] where ROOM = @ROOM_Data";
    string connStr = ConfigurationManager.ConnectionStrings["TDBConnection"].ConnectionString;
    var jsonResult = new StringBuilder();
    using (SqlConnection connection = new SqlConnection(connStr)) {
        using (SqlCommand command = new SqlCommand(commandText, connection)) {
            command.Parameters.Add("@ROOM_Data", SqlDbType.VarChar);
            command.Parameters["@ROOM_Data"].Value = ROOM;
            connection.Open();
            List<DatabaseResult> records = new List<DatabaseResult>();
            using (var reader = command.ExecuteReader()) {
                while (reader.Read()) {
                    var row = new DatabaseResult {
                        r_id = (int)reader["r_id"],
                        room = (string)reader["room"],
                        //...other properties.
                    };
                    records.Add(row);
                }
                return Ok(records);
            }
        }
    }
}

以上使用列名作为索引器从 reader.

中获取值

Web API 查询 SQL 服务器和 return 结果未按预期工作

Web API to query SQL Server and return result is not working as expected

asp.net

sql-server

asp.net-web-api

sqlconnection

sqlcommand