select Count (*) from with two arguments

First I tried it with datetime but it didn't worked for me.

I have one table with basic information. It is ID, activeagent (stands for antibiotics), DDD (daily defiened dose), and ATC-Code (from the WHO). The second table is used to record the consumption for each antibiotic within on quarter (for example 01/15 january to march). For example 200 g (=totalamount) Penicilline. Later I want to devide the totalamount / DDD. Each antibiotic can have only one totalamount per quarter.

Hope it helps.

thanks

Thanks a lot so far.

Here is a sample of the two tables (I hope this is OK)

<pre lang="text">Table Wirkstoffe;

ID: 11 (autoincrement)
ATCCode: J01DC02 (string)
activeagent: Cefuroxim (string)
form: i.v. (string)
DDD: 3.00 (decimal)

ID: 9
ATCCode: J01CA04
activeagent: Amoxicillin
form: i.v.
DDD: 2

ID: 9
ATCCode: J01CA04
activeagent: Amoxicillin
form: p.o.
DDD: 2

table: calculatedconsumption
ID: 23
agent_ID: 11 (foreign key)
totalamount: 100 (decimal)
time: 01/15 (until now string but will changed to datetime) (user can select 01/15, 02/15,0315,04/15 from a combobox)
ward_ID: foreign key (table ward with ward ICU, etc)
dailydose: totalamount / DDD
consumptiondensity: (dailydose / count of patient days) * 100 (count of patient days is not set yet)
</pre>

User can insert for each activeagent per time per ward one totalamount using a windows form. for now is it not necessary to distinguish between the form (i.v. or p.o.). Problem now how can I controll if a record e.g. Cefuroxim 01/15 ICU already exists?

here is a sample for insert data into calculatedconsumption (ward is not set yet)
<pre>private void button5_Click(object sender, EventArgs e)
{
string mycon = "server=xxx.xxx.xxx.xx;port=3306;username=xxx;password=xxx;database=Antibiotikaverbrauch;";
string dbselectID = "select ID from Wirkstoffe where activeagent='" + comboBox4.Text + "'; ";
MySqlConnection myconnection = new MySqlConnection(mycon);
MySqlCommand cmd = new MySqlCommand(dbselectID, myconnection);
MySqlDataReader myreader;

try
{
myconnection.Open();
myreader = cmd.ExecuteReader();
while (myreader.Read())
{
string sid = myreader.GetString("ID");
int snid = Convert.ToInt32(sid);
MessageBox.Show(sid, dbselectID);
string mycon2 = "server=xxx.xxx.xxx.xx;port=3306;username=xxx;password=xxx;database=Antibiotikaverbrauch;";
string dbinsert = "insert into calculatedconsumption (time,totalamount,agent_ID) values ('" + this.comboBox5.Text + "','" + this.textBox6.Text + "','" + snid + "'); ";
MySqlConnection myconnection2 = new MySqlConnection(mycon2);
MySqlCommand cmd2 = new MySqlCommand(dbinsert, myconnection2);
MySqlDataReader myreader2;
myconnection2.Open();
myreader2 = cmd2.ExecuteReader();
myconnection2.Close();
myreader2.Close();
}
myreader.Close();
myconnection.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}</pre>

I now it is not good but I am realy a beginner and I learn every day something new :-)