CODEWITHSUNDEEP
asp.netmysqldatabasenulldbnull
James
James

Reputation: 7533

Handling DBNull and null in ASP.NET

What is the best way of rewriting these (erroneous) lines?

bool? result = dr["result"] == DBNull.Value ? null : Convert.ToInt32(dr["result"]);

...and...

dr["result"] = result ?? DBNull.Value;

Both do not compile.

I am using the MySql connector and it doesn't let me set, for example, dr["result"] = null; which is what I first tried.

Is there an more suitable .NET data type for representing a MySql nullable tinyint(1)?

Upvotes: 1

Views: 2046

Answers (2)

Gaurav Agrawal
Gaurav Agrawal

Reputation: 4431

If you are using a stored procedure or SQL queries then you can use ISNULL() function of SQL to handle NULL...

Upvotes: -1

DeCaf
DeCaf

Reputation: 6086

How about:

     dr["Hello"] = (object)result ?? DBNull.Value;
     bool? result = dr["result"] == DBNull.Value ? null : (bool?)(Convert.ToInt32(dr["result"]) != 0);

The reason your suggestion does not compile is that both alternatives of the ternary operator ?: must have the same type. DBNull.Value obviously is not the same type as a bool?. Casting the bool? to an object however makes them both the same type. Similar rules apply on the second row.

Upvotes: 2

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