RE: Return parameter from query.

[Reggie Burnett]

Out, intout, and return parameters are only supported when dealing with
stored procedures in 5.0 and later.  For what you are doing, you should
not use a parameter.  See this code.

MySqlCommmand cmd = new MySqlCommand("SELECT MAX(ID) FROM myTable",
conn);
Object max = cmd.ExecuteScalar();

HTH,
Reggie

-----Original Message-----
From: Asbjørn Konstad [mailto:asbjorn@stripped] 
Sent: Friday, September 24, 2004 3:06 AM
To: dotnet@stripped
Subject: Return parameter from query.

Hi.

 

Anyone as frustrated as me???

 

Problem:

I have a created a command to return maximum id from myTable.., like
this:

 

//----------------------------------------------------------------------
----
------------------------------------------------------------------------
----
-----

 

MySqlCommand cmd = new MySqlCommand(“SELECT @PAR := MAX(ID) FROM
myTable”,
myConnection);

MySqlParameter param = new MySqlParameter();

param = cmd.Parameters.Add(“@PAR”, MySqlDbType.Int32, 4);

param.Direction = ParameterDirection.Output;

 

myConnection.Open();

  cmd.ExecuteNonQuery();

  int max_id = (int)cmd.Parameters[“@PAR”].Value;

myConnection.Close();

 

//----------------------------------------------------------------------
----
------------------------------------------------------------------------
----
----

 

This gives me an error -> “error in SQL-Syntax”.

I read the issue with use of “?” instead of “@”, and I’ve tried it
all……!,
it keeps throwing exeptions like “null values” 

“Object reference not set to an instance of an object”… and so on.

 

Anyone have a fail-proof method of creating a command with
return-parameters??

 

Thanks.

 

Reg.

 

Asbjørn Konstad


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