The Weird and The Wonderful

PIEBALDconsult wrote:

As with Jörgen's post, an IN with hard-coded values I especially discourage; they reek of the "magic numbers" code smell. A subquery on some table would at least improve maintainability.

Jörgen Andersson wrote:

list as a parameter

db.Command.CommandText = "SELECT * FROM Account WHERE ID IN ( SELECT ID FROM @IDs )" ;
                
System.Data.SqlClient.SqlParameter p = 
    new System.Data.SqlClient.SqlParameter 
    ( "@IDs" , System.Data.SqlDbType.Structured ) ;

p.TypeName = "dbo.IDdef" ;

p.Value = dt ;

db.Command.Parameters.Add ( p ) ;
               
db.Open() ;
                
System.Data.IDataReader dr = db.Command.ExecuteReader 
    ( System.Data.CommandBehavior.CloseConnection ) ;

PIEBALDconsult wrote:

Personally I wouldn't. I wouldn't use IN at all, I'd find a way to have a table on which to JOIN instead.

PIEBALDconsult wrote:

The statement you present is a symptom of a poorly implemented system.

string query = "select * from table where ID in (@value1, @value2, @value3)";
SqlCommand cmd = new SqlCommand(query);
cmd.Parameters.Add("@value1", 123);
cmd.Parameters.Add("@value2", 124);
cmd.Parameters.Add("@value3", 125);

string query = "select * from table where (ID = @value1 or ID = @value2 or ID = @value3)";
SqlCommand cmd = new SqlCommand(query);
cmd.Parameters.Add("@value1", 123);
cmd.Parameters.Add("@value2", 124);
cmd.Parameters.Add("@value3", 125);

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{
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    ....
}