Question

I have to compare a value in a string array to that of a particular column in a database. How do i do this ?

  public void setvisibility(string user_ID)
{
    SqlDataReader reader = null;
    SqlConnection connection = new SqlConnection(WebConfigurationManager.ConnectionStrings["ctd_prrity_dbConnectionSting"].ConnectionString);
    connection.Open();\
SqlCommand cmd = new SqlCommand("Select * from Admins );

I need to compare the value of user_ID to the only column in the Admins table !

Answer 1

Here’s how you can do it:

using( SqlConnection connection = new SqlConnection(WebConfigurationManager.ConnectionStrings["ctd_prrity_dbConnectionSting"].ConnectionString))
{ 
  connection.Open();   
  SqlCommand cmd = new SqlCommand("Select 1 from Admins where User_ID=@userid",connection );
  cmd.Parameters.AddWithValue("@userid",user_ID);
  SqlDataReader reader= cmd.ExecuteReader();
  if(reader.HasRows)
  {
   //user id found
  }
}

This method uses a parametrized queries, which are safer than the option given in the answer by Tony since his is prone to SQL Injection attacks.

BTW: you mention “string array” in your question, yet your code only shows a single string as parameter. What did you mean by that?