MySQL Bugs: #5388: DataReader reports all rows as NULL if one row is NULL

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Bug #5388	DataReader reports all rows as NULL if one row is NULL
Submitted:	3 Sep 2004 12:15	Modified:	30 Sep 2004 12:23
Reporter:	Christian Hornung	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / NET	Severity:	S1 (Critical)
Version:	1.0.0.22722	OS:	Windows (Win XP SP1)
Assigned to:	Reggie Burnett	CPU Architecture:	Any

Description:
A query result is being read by a MySqlDataReader or MySqlDataAdapter. If there is a row with a NULL value in any column, all following rows will also have this column set to NULL, although they have other values in the actual table.

How to repeat:
Run this code:

MySqlConnection conn = new MySqlConnection("Server=...;Database=test;Password=...;User ID=...");
conn.Open();

MySqlCommand cmd = conn.CreateCommand();

cmd.CommandText = "CREATE TABLE testnull (val SMALLINT(5) NULL)";
cmd.ExecuteNonQuery();

cmd.CommandText = "INSERT INTO testnull VALUES (1000), (2000), (3000), (NULL), (4000), (5000), (6000)";
cmd.ExecuteNonQuery();

cmd.CommandText = "SELECT val FROM testnull";
MySqlDataReader rd = cmd.ExecuteReader();
while (rd.Read()) {
	if (rd.IsDBNull(0)) {
		System.Console.WriteLine("NULL");
	} else {
		System.Console.WriteLine(rd[0]);
	}
}
rd.Close();
System.Console.ReadLine();

conn.Close();

------------------------------------------------------------------------

Logically, the output should be:
1000
2000
3000
NULL
4000
5000
6000

But it is:
1000
2000
3000
NULL
NULL
NULL
NULL

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Can you confirm '3rd Sep' mentioned on this bug is 2004? (there's no mention of a year anywhere, so I can't tell if this is a recent bug or not).

I upgraded due to ByteFX's problem reading BLOB fields, but seem to be hitting many more bugs in the MySql provider :o(

Thanks.

MySqlClient\Field.cs, line 263
+ colValue.IsNull = false;

MySqlClient\Field41.cs, line 79
+ colValue.IsNull = false;

That fixed the problem for me. I don't know if there is another cleaner way to fix it.

Yes, the fix was very similar