c# - Is there a better way to dynamically build an SQL WHERE clause than by using 1=1 at its beginning?

Question

I'm building some SQL query in C#. It will differ depending on some conditions stored as variables in the code.

string Query="SELECT * FROM Table1 WHERE 1=1 ";
if (condition1) 
    Query += "AND Col1=0 ";
if (condition2) 
    Query += "AND Col2=1 ";
if (condition3) 
    Query += "AND Col3=2 ";

It works, but testing 1=1 doesn't seem elegant. If I didn't use it, I would have to remember and check every time if "where" keyword was already added or not to the query.

Is there a nicer solution?

Answer 1

Save the conditions in a list:

List<string> conditions = new List<string>();

if (condition1) conditions.Add("Col1=0");
//...
if (conditions.Any())
    Query += " WHERE " + string.Join(" AND ", conditions.ToArray());