使用 C# 更新 SQL table

Question

我正在尝试更新剧集 table 中的 EpisodeId no:117 并且它执行成功，但是当我检查 table 时它没有更新。 int 剧集 ID = 117;

int seriesNumber = 9;
int episodeNumber = 13;
string episodeType = "abnormal episode";
string title = "Reconsideration";
string notes = "recuring behaviour";

//connectionString
 
string connectionString = "data source=LAPTOP-VLO4EFFQ\MSSQLSERVER01; database=DoctorWho; integrated Security=True;";

//connection using
using (SqlConnection conn = new SqlConnection(connectionString))
{
    
    conn.Open();
    Console.WriteLine("Connection sucessfull");

    string query = "UPDATE tblEpisode " +
        "(SeriesNumber, EpisodeNumber, EpisodeType, Title, Notes)" +
        "(SET SeriesNumber=@SeriesNumber, EpisodeNumber=@EpisodeNumber, EpisodeType=@EpisodeType, Title=@Title, Notes=@Notes)" +
        "(WHERE EpisodeId=@EpisodeId)";

    using (SqlCommand command = new SqlCommand(query, conn))
    {
        //updating data in the sql table with the initial variables  
        command.Parameters.Add("@EpisodeId", System.Data.SqlDbType.Int).Value = episodeId;
        command.Parameters.Add("@SeriesNumber", System.Data.SqlDbType.Int).Value = seriesNumber;
        command.Parameters.Add("@EpisodeNumber", System.Data.SqlDbType.Int).Value = episodeNumber;
        command.Parameters.Add("@EpisodeType", System.Data.SqlDbType.NVarChar).Value = episodeType;
        command.Parameters.Add("@Title", System.Data.SqlDbType.NVarChar).Value = title;
        command.Parameters.Add("@Notes", System.Data.SqlDbType.NVarChar).Value = notes;

    }


    conn.Close();
    Console.WriteLine("connection is closed!!");
}

Answer 1

您的 SQL 更新 statement.Look 存在一些问题，请参考 SQL LINK

中的更新声明

还有一种更简单的方法可以使用 AddWithValue 方法添加参数。 LINK

接下来，你不是在执行SQL命令。对于 Update 语句，请使用 ExecuteNonQuery() 方法。 LINK

同样如@Nikki9696 所述，未声明 episodeId。确保使用其他变量声明 episodeId。

int episodeId = 117;
int seriesNumber = 9;
int episodeNumber = 13;
string episodeType = "abnormal episode";
string title = "Reconsideration";
string notes = "recuring behaviour";

//connectionString

string connectionString = "data source=LAPTOP-VLO4EFFQ\MSSQLSERVER01; database=DoctorWho; integrated Security=True;";

//connection using
using (SqlConnection conn = new SqlConnection(connectionString))
{

conn.Open();
Console.WriteLine("Connection sucessfull");

string query = "UPDATE tblEpisode " +        
    "SET SeriesNumber=@SeriesNumber, EpisodeNumber=@EpisodeNumber, EpisodeType=@EpisodeType, Title=@Title, Notes=@Notes " +
    " WHERE EpisodeId=@EpisodeId;";

using (SqlCommand command = new SqlCommand(query, conn))
{
    //updating data in the sql table with the initial variables  
    command.Parameters.AddWithValue("@EpisodeId", episodeId);
    command.Parameters.AddWithValue("@SeriesNumber", seriesNumber);
    command.Parameters.AddWithValue("@EpisodeNumber", episodeNumber);
    command.Parameters.AddWithValue("@EpisodeType", episodeType);
    command.Parameters.AddWithValue("@Title", title);
    command.Parameters.AddWithValue("@Notes", notes);
    
    command.ExecuteNonQuery();

}


conn.Close();
Console.WriteLine("connection is closed!!");
}

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