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How to check which primary key a record was assigned to in C#?

I'm using the OleDBConnectivity system to connect and use a Microsoft Access database.
I'm adding a record to the table in the database called "PayInfo", and the primary key is automatically set to the next available integer. How do I check what the value of the primary key it was assigned to is? I know this is probably an awful idea, but the only thing I could think of was to re-read the database using the entered values. The issue with this, though it's very unlikely, is that its possible to have 2 identical records stored in the database, their only difference being the primary key, and I need to be able to read the specific one.
My current subroutine for adding the record to the database is as follows:
OleDbCommand command = connection.CreateCommand();
connection.Open();
// The SQL statement:
command.CommandText = "INSERT INTO PayInfo ([UserID], [FullName], [CardType], [CardNo], [CVV], [ExpDate], [Address])" +
"VALUES ('" + Global.UserID.ToString() + "','" + PayInfo[6] + "','" + PayInfo[0] + "','" + PayInfo[1] + "','" + PayInfo[2] + "','" + exp + "','" + adress + "')";
command.Connection = connection;
command.ExecuteNonQuery(); //executes the SQL command.
connection.Close();
return true; //Successful transaction

After executing your insert query, you need to execute another query to get the generated primary key:
command.Parameters.Clear();
command.CommandText = "SELECT ##IDENTITY";
int primaryKey = Convert.ToInt32(Command.ExecuteScalar());
See Microsoft: Retrieving Identity or Autonumber Values for more details:
The Jet database engine does not support the execution of multiple
statements in a batch or the use of output parameters, so it is not
possible to use either of these techniques to return the new
Autonumber value assigned to an inserted row. However, you can add
code to the RowUpdated event handler that executes a separate SELECT
##IDENTITY statement to retrieve the new Autonumber value.

My query keeps rubbish in my sql table if it will not be complete properly

I'm using a a multiple query with insert and update statement together.
The problem is that if query will not be completed(for some reason e.x bad internet connection) my SQL Server table keeps rubbish.
Example of query:
SqlCommand cmd = new SqlCommand("INSERT INTO CustomerTrans (TableName, UserID, UserName, SumQuantity, SumPrice, SumRealPrice, SumExtrasPrice, SumTotal, SumDiscountTotal, DateTime) SELECT " + Connection.TableName + ",' " + Connection.UserID + "', '" + Connection.Username + "',Sum(Quantity),Sum(Price),Sum(RealPrice),Sum(ExtrasPrice), Sum(Quantity * Price),Sum(Quantity * DiscountPrice),'" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + "' from InventoryTransTemp where active=1 and TableName=" + Connection.TableName + ";update InventorytransTemp set TrnDocumentID=(select max(TrnDocumentID) from CustomerTrans where UserID='" + Connection.UserID + "'),Active=0 where TableName=" + Connection.TableName + " and Active=1", con);
cmd.ExecuteNonQuery();
Take a photo from a query which has not be completed properly look query 2989 it has NULL values. I want to avoid inserting something if query is not be completed properly.
Sorry for my previous Question it was Unclear

Try it like this:
string sql =
"INSERT INTO CustomerTrans" +
" (TableName, UserID, UserName, SumQuantity, SumPrice, SumRealPrice, SumExtrasPrice, SumTotal, SumDiscountTotal, DateTime)" +
" SELECT #TableName, #UserID, #Username, Sum(Quantity), Sum(Price), Sum(RealPrice), Sum(ExtrasPrice), Sum(Quantity * Price), Sum(Quantity * DiscountPrice), current_timestamp" +
" FROM InventoryTransTemp" +
" WHERE active=1 and TableName= #TableName;\n" +
"SELECT #TranID = scope_identity;\n"
"UPDATE InventorytransTemp" +
" SET TrnDocumentID=#TranID ,Active=0" +
" WHERE TableName= #Tablename and Active=1;";
using (var con = new SqlConnection("connection string here"))
using (var cmd = new SqlCommand(sql, con))
{
//I'm guessing at exact column types/lengths here.
// You should update this to use your exact column types and lengths.
// Don't let ADO.Net try to guess this for you.
cmd.Parameters.Add("#TableName", SqlDbType.NVarChar, 20).Value = Connection.TableName;
cmd.Parameters.Add("#UserID", SqlDbType.Int).Value = Connection.UserID;
cmd.Parameters.Add("#Username", SqlDbType.NVarChar, 20).Value = Connection.Username;
cmd.Parameters.Add("#TranID", SqlDbType.Int).Value = 0; //placeholder only
con.Open();
cmd.ExecuteNonQuery();
}
Note the improved formatting of the query, the use of scope_identity() to get the new identity value rather than a nested select statement that might not be atomic, that I avoided ALL uses of string concatenation to substitute data into the query, that I avoided the AddWithValue() method entirely in favor of an option that doesn't try to guess at your parameter types, and the use of using blocks to be sure the SqlClient objects are disposed properly.
The only thing I'm still concerned about is if your INSERT/SELECT operation might create more than one new record. In that case, you'll need to handle this a different way that probably involves explicit BEGIN TRANSACTION/COMMIT statements, because this code only gets one #TranID value. But in that case, the original code was broken, too.

Save record in database and get its referance immediately in C# and MySQL [duplicate]

I have a query to insert a row into a table, which has a field called ID, which is populated using an AUTO_INCREMENT on the column. I need to get this value for the next bit of functionality, but when I run the following, it always returns 0 even though the actual value is not 0:
MySqlCommand comm = connect.CreateCommand();
comm.CommandText = insertInvoice;
comm.CommandText += "\'" + invoiceDate.ToString("yyyy:MM:dd hh:mm:ss") + "\', " + bookFee + ", " + adminFee + ", " + totalFee + ", " + customerID + ")";
int id = Convert.ToInt32(comm.ExecuteScalar());
According to my understanding, this should return the ID column, but it just returns 0 every time. Any ideas?
EDIT:
When I run:
"INSERT INTO INVOICE (INVOICE_DATE, BOOK_FEE, ADMIN_FEE, TOTAL_FEE, CUSTOMER_ID) VALUES ('2009:01:01 10:21:12', 50, 7, 57, 2134);last_insert_id();"
I get:
{"You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'last_insert_id()' at line 1"}

MySqlCommand comm = connect.CreateCommand();
comm.CommandText = insertStatement; // Set the insert statement
comm.ExecuteNonQuery(); // Execute the command
long id = comm.LastInsertedId; // Get the ID of the inserted item

[Edit: added "select" before references to last_insert_id()]
What about running "select last_insert_id();" after your insert?
MySqlCommand comm = connect.CreateCommand();
comm.CommandText = insertInvoice;
comm.CommandText += "\'" + invoiceDate.ToString("yyyy:MM:dd hh:mm:ss") + "\', "
+ bookFee + ", " + adminFee + ", " + totalFee + ", " + customerID + ");";
+ "select last_insert_id();"
int id = Convert.ToInt32(comm.ExecuteScalar());
Edit: As duffymo mentioned, you really would be well served using parameterized queries like this.
Edit: Until you switch over to a parameterized version, you might find peace with string.Format:
comm.CommandText = string.Format("{0} '{1}', {2}, {3}, {4}, {5}); select last_insert_id();",
insertInvoice, invoiceDate.ToString(...), bookFee, adminFee, totalFee, customerID);

Use LastInsertedId.
View my suggestion with example here: http://livshitz.wordpress.com/2011/10/28/returning-last-inserted-id-in-c-using-mysql-db-provider/

It bothers me to see anybody taking a Date and storing it in a database as a String. Why not have the column type reflect reality?
I'm also surprised to see a SQL query being built up using string concatenation. I'm a Java developer, and I don't know C# at all, but I'd wonder if there wasn't a binding mechanism along the lines of java.sql.PreparedStatement somewhere in the library? It's recommended for guarding against SQL injection attacks. Another benefit is possible performance benefits, because the SQL can be parsed, verified, cached once, and reused.

Actually, the ExecuteScalar method returns the first column of the first row of the DataSet being returned. In your case, you're only doing an Insert, you're not actually querying any data. You need to query the scope_identity() after you're insert (that's the syntax for SQL Server) and then you'll have your answer. See here:
Linkage
EDIT: As Michael Haren pointed out, you mentioned in your tag you're using MySql, use last_insert_id(); instead of scope_identity();

Syntax error in INSERT INTO statement c#.net Winforms Devexpress?

I get date from DateEdit and try to Store into Access Database. But it show error like this
Syntax error in INSERT INTO statement.
my insert statement is this
OleDbCommand top = new OleDbCommand("INSERT INTO invoice(invoice_number,order_number,customername,status,subtotal,tax,total,date) VALUES (" + inno + "," + odrno + ",'" + name + "','"+ chk1 +"' ,"+ subtottal +","+ tax +","+total+",'"+date+"')", conn);
top.ExecuteNonQuery();
Except Date remaining values store successfully but how can i store date ??
I get date like this DateTime date = dateEdit1.DateTime;
Help me.

DATE is a reserved keyword for Microsoft Access. You shoud use it with square brackets like [DATE]
And you should always use parameterized queries. This kind of string concatenations are open for SQL Injection attacks.
OleDbCommand top = new OleDbCommand(#"INSERT INTO invoice(invoice_number,order_number,customername,status,subtotal,tax,total,[date])
VALUES (#invoice_number, #order_number, #customername, #status, #subtotal, #tax, #total, #date)", conn);
top.Parameters.AddWithValue("#invoice_number", inno);
top.Parameters.AddWithValue("#order_number", odrno);
top.Parameters.AddWithValue("#customername", name);
top.Parameters.AddWithValue("#status", chk1);
top.Parameters.AddWithValue("#subtotal", subtotal);
top.Parameters.AddWithValue("#tax", text);
top.Parameters.AddWithValue("#total", total);
top.Parameters.AddWithValue("#date", date);
As a general recommendation, don't use reserved keywords for your identifiers and object names in your database.

Insert datetime from C# into SQL Server database

when I try to insert datetime value into a SQL Server database I get this error:
Conversion failed when converting date and/or time from character string
Code:
connection.Open();
SqlCommand command = new SqlCommand("insert into table values(#time)", connection);
command.Parameters.AddWithValue("#time", DateTime.Now);
command.ExecuteNonQuery();
connection.Close();
Table table has 1 datetime column called time.
Edit:
my table created in msSQL 2012: http://i.imgur.com/TJ3t3y7.png
my real code is:
public void vytvorDotaz(String uzivatel, DateTime cas, String nazev, String dotaz)
{
int id = getMaxID() + 1;
connection.Open();
SqlCommand command = new SqlCommand("insert into otazky values('" + id + "', '" + uzivatel + "', '0','0','0','#cas','" + nazev + "','" + dotaz + "')", connection);
command.Parameters.AddWithValue("#cas", DateTime.Now);
command.ExecuteNonQuery();
connection.Close();
}

The actual problem here is that you're writing the parameter inside quotes:
... ,'0','#cas',' ...
^ ^
This will not use #cas as a parameter, you're actually trying to insert the string "#cas" into that column, not the contents of the parameter #cas.
Remove the quotes and that part should work.
Additionally, don't use string concatenation to build up the SQL, use parameters for everything, save you some headache from SQL injection attacks or quotes or whatnot. This is related to the "id", "uzivatel", "nazev", and "dotav" parameters you're using (method parameters that is).

Looks like you need:
insert into table values(#time)
Without the single character quote.

Try System.Data.SqlTypes.SqlDateTime Also when storing dates please consider storing them as UTC to prevent confusion.