How to convert an expression tree to a partial SQL query?

Question

When EF or LINQ to SQL runs a query, it:

1. Builds an expression tree from the code,
2. Converts the expression tree into an SQL query,
3. Executes th

Answer 1

It isn't complete, but here are some thoughts for you to groove on if you come by this later:

    private string CreateWhereClause(Expression> predicate)
    {
        StringBuilder p = new StringBuilder(predicate.Body.ToString());
        var pName = predicate.Parameters.First();
        p.Replace(pName.Name + ".", "");
        p.Replace("==", "=");
        p.Replace("AndAlso", "and");
        p.Replace("OrElse", "or");
        p.Replace("\"", "\'");
        return p.ToString();
    }

    private string AddWhereToSelectCommand(Expression> predicate, int maxCount = 0)
    {           
        string command = string.Format("{0} where {1}", CreateSelectCommand(maxCount), CreateWhereClause(predicate));
        return command;
    }

    private string CreateSelectCommand(int maxCount = 0)
    {
        string selectMax = maxCount > 0 ? "TOP " + maxCount.ToString() + " * " : "*";
        string command = string.Format("Select {0} from {1}", selectMax, _tableName);
        return command;
    }