CODEWITHSUNDEEP
c#.netvisual-studiovisual-studio-2008
Penguen
Penguen

Reputation: 17298

How can i trim or remove " , " at the end of my query?

i try to write a query but my query finished with "Control nvarchar(500), ". i want to finish "Control nvarchar(500)" How can remove ",", " "?

 void SqlTable(List listMyColumnNames, string TableName)
        {

            string  Text = "Create table ENG_"+TableName+" (ENG_"+TableName+"_ID integer PRIMARY KEY identity(1,1), ";
            char[] MyChar = {',', ' ' };
            for (int i = 0; i < listMyColumnNames.Count; )
            {
                 Text+=listMyColumnNames[i]+" nvarchar(500), ";
                 if (i == listMyColumnNames.Count-1)
                     Text.TrimEnd(MyChar);
                 i++;
            }
            Text+=" )";

Upvotes: 2

Views: 176

Answers (5)

openshac
openshac

Reputation: 5165

Have you thought about using the StringBuilder object to build your string, rather than concatenating yours string in a loop!

http://www.yoda.arachsys.com/csharp/stringbuilder.html

Upvotes: 0

Hans Olsson
Hans Olsson

Reputation: 55039

Or you could just remove your Trim call and add `Text = Text.Replace(", )", " )");' at very end.

Upvotes: 0

xtofl
xtofl

Reputation: 41519

I think you may want to look at String.Join. What you can do is transform your column name strings, containing the SQL definition of your colum, e.g. MyColumnName[1]+" nvarchar(500)", into alistMyColumnDefarray, thenJoin` that array with the comma as a separator.

The benefit:

  • no 'if I'm the last entry',
  • clear separation of your column names and your SQL representation for a column

The drawbacks.... none :)

for( String name in listMyColumnNames ) {
   listMyColumnDefs.Add( name + " nvarchar(500)" );
}

String mycolumndef = String.Join( listMyColumnDefs, ", ");

Upvotes: 11

polygenelubricants
polygenelubricants

Reputation: 383866

There are many ways to fix this, but here's the problem in your code:

             if (i == listMyColumnNames.Count-1)
                 Text.TrimEnd(MyChar); // doesn't work like this!

String is immutable: you can't invoke a method on it and expect it to be mutated by the method. TrimEnd instead returns a new String, so what you need to do is:

                 Text = Text.TrimEnd(MyChar); // now works fine!

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Upvotes: 3

sbi
sbi

Reputation: 224129

        for (int i = 0; i < listMyColumnNames.Count; ++i)
        {
             Text += listMyColumnNames[i] + " nvarchar(500)";
             if (i < listMyColumnNames.Count-1)
                 Text += ", ";
        }

Upvotes: 0

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