Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
572 views
in Technique[技术] by (71.8m points)

c# - SqlCommand read one value

I have a problem with the value returned from SqlCommand, I have this code:

string sqlSelect = "Select TOP 1 Quotation.SentToSupp as SentToSupp FROM Quotation JOIN Notifications ON Quotation.QuotationId = QuotationID ";

SqlCommand Comm = new SqlCommand(sqlSelect, this.Connection);

sqlSelect query selects the first DateTime value. When I call to SqlCommand I want to get this value (just one value). I add the query and my connection fine.

But I don't know how to get my DateTime value... Must to use something like ExecuteReader?

Thank you in advance!!

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

ExecuteReader works but more objects and more code are required - (An SqlDataReader, call to Read and Extract value). Instead you could simply use the ExecuteScalar method of the SqlCommand object (It returns just the first column of the first row of the resultset)

string sqlSelect = "Select TOP 1 Quotation.SentToSupp as SentToSupp FROM ....";
SqlCommand Comm = new SqlCommand(sqlSelect, this.Connection);
object result = Comm.ExecuteScalar();
if(result != null)
   DateTime dtResult = Convert.ToDateTime(result);

Just pay attention to the fact that ExecuteScalar could return a null value if, for some reason, there is no record in the result returned


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...