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how to get the last record number after inserting record to database in access
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Closed 1 year ago.
Am working with Access as Database in C# (Visual Studio 15). I want to save form entries (add record) into the Access Database and would want the corresponding ID of the record to show in MsgBox upon a successful saving. I have tried the following:
private void Form21_Load(object sender, EventArgs e)
{
try
{
connection.Open();
checkConnection.Text = "Server Connection, Successful";
connection.Close();
}
catch (Exception ex)
{
MessageBox.Show("Error, Server not connected " + ex);
}
}
private void Button6_Click(object sender, EventArgs e)
{
connection.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = connection;
command.CommandText = "insert into Students_File ([YourNames],[Nationality],[StateOfOrigin],[PlaceOfBirth],[DoB],[HomeAddress],[LastSchools1],[LastClass1],[LastSchools2],[LastClass2],[LastSchools3],[LastClass3],[AdmClass],[CurrentClass],[Guidian],[GuardianContact],[UserName],[PassWord],[Gender],[RegistrationDate]) values('" + YourNames.Text + "','" + Nationality.Text + "','" + StateOfOrigin.Text + "','" + PlaceOfBirth.Text + "','" + DoB.Text + "','" + HomeAddress.Text + "','" + LastSchools1.Text + "','" + LastClass1.Text + "','" + LastSchools2.Text + "','" + LastClass2.Text + "','" + LastSchools3.Text + "','" + LastClass3.Text + "','" + AdmClass.Text + "','" + CurrentClass.Text + "','" + Guidian.Text + "','" + GuardianContact.Text + "','" + UserName.Text + "','" + PassWord.Text + "','" + Gender.Text + "','" + RegistrationDate.Text + "')";
command.ExecuteNonQuery();
//MessageBox.Show("Congrats! Your registration, is successful. You may now click close button, then proceed to login");
command.CommandText = "Select * from Students_File where UserName='" + UserName.Text + "' and PassWord='" + PassWord.Text + "'";
OleDbDataReader reader = command.ExecuteReader();
int count = 0;
while (reader.Read())
{
count = count + 1;
}
if (count == 1)
{
MessageBox.Show("Congrats! Your registration, is successful. You may now click close button, then proceed to login");
this.Close();
}
else if (count > 1)
{
MessageBox.Show("Sorry, the chosen username or password is currently existing or picked by another user. Consequently, your registration was not successful. Do please, decide another but a unique one. Thank you");
}
connection.Close();
}
You can do it this way:
using (OleDbCommand Command = new OleDbCommand("", conn))
{
Command.CommandText = "Your big ugly mess - need to change this to parmaters!)";
Command.Connection.Open();
Command.ExecuteNonQuery();
Command.CommandText = "Select ##Identity";
var intLastID = Command.ExecuteScalar;
MsgBox("Last id into database = " + intLastID);
}
As noted, you do want to change that insert command - it too long, too difficult to maintain, and subject to mistakes in code and even sql injection.
But, for now, you can use the above approach to get/pick up the last ID insert.
In solution to my inquiry, i have the following code (From Kevin):
string query = "Insert Into Categories (CategoryName) Values (?)";
string query2 = "Select ##Identity";
int ID;
string connect = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|Northwind.mdb";
using (OleDbConnection conn = new OleDbConnection(connect))
{
using (OleDbCommand cmd = new OleDbCommand(query, conn))
{
cmd.Parameters.AddWithValue("#CategoryName", OleDbType.Integer);
conn.Open();
cmd.ExecuteNonQuery();
cmd.CommandText = query2;
ID = (int)cmd.ExecuteScalar();
}
}
Now, my challenge is how do i get the ID to appear in messagebox after a successful record creation. Please consider my earliest code in this post in connection with this.
My SQLite query hangs then locks during my ExecuteNonQuery() in WriteToDB() below. It only seems to lock during the UPDATE and has no problem with the INSERT. This is only running in a single thread. When it hangs, I can see the journal being created in the SQLite database directory as if it keeps trying to write. It throws a SQLiteException with ErrorCode=5, ResultCode=Busy.
public String WriteToDB()
{
String retString = "";
//see if account exists with this email
String sql = "";
bool aExists = AccountExists();
if (!aExists)
{
sql = "INSERT INTO accounts (email, password, proxy, type, description) VALUES ('" + Email + "', '" + Password + "', '" + Proxy + "', 'dev', '" + Description + "');";
retString = "Added account";
}
else
{
sql = "UPDATE accounts SET password='" + Password + "', proxy='" + Proxy + "', description='" + Description + "' WHERE (email='" + Email + "' AND type='dev');";
retString = "Updated account";
}
using (SQLiteConnection dbconn = new SQLiteConnection("Data Source=" + Form1.DBNAME + ";Version=3;"))
{
dbconn.Open();
using (SQLiteCommand sqlcmd = new SQLiteCommand(sql, dbconn))
{
sqlcmd.ExecuteNonQuery(); //this is where it locks. Only on update.
}
}
return retString;
}
//Test to see if Email exists as account
public bool AccountExists()
{
int rCount = 0;
String sql = "SELECT COUNT(email) FROM accounts WHERE email='" + Email + "' AND type='dev';";
using (SQLiteConnection dbconn = new SQLiteConnection("Data Source=" + Form1.DBNAME + ";Version=3;"))
{
dbconn.Open();
using (SQLiteCommand sqlcmd = new SQLiteCommand(sql, dbconn))
{
rCount = Convert.ToInt32(sqlcmd.ExecuteScalar());
}
}
if (rCount > 0)
return true;
return false;
}
Oh man I feel dumb. I thought I posted all relevant code but all the code I posted works just fine. I had:
SQLiteDataReader dbReader = sqlcmd.ExecuteReader()
instead of
using (SQLiteDataReader dbReader = sqlcmd.ExecuteReader())
In another function. I thought it was an issue with the UPDATE because that was the place where the lock took place. Thanks for the responses and hopefully this reminds reminds everyone to use using() blocks with SQLite the first time!
I need to get the userid(primary key auto_increment) from another table(login) into userdetails table. When trying to run it I keep getting this error " incorrect integer value: 'LAST_INSERT_ID()' for column 'userid' at row 1".
I've tried to take LAST_INSERT_ID() out and run another query after query4 to insert the value into the userid but I can't get it to insert into the right row it just opens a new row.
this is the code am trying to run.
try
{
//This is my connection string i have assigned the database file address path
string MyConnection2 = "datasource=localhost;port=3310;database=e-votingsystem;username=root;password=Password12;";
//this is my insert query in which i am taking input from the user through windows forms
string Query2 = "INSERT INTO vote (username) VALUE ('" + usernameInputBox.Text + "');";
string Query3 = "INSERT INTO login (username,upassword) VALUE ('" + usernameInputBox.Text + "','" + passwordInputBox.Text + "');";
string Query4 = "INSERT INTO userdetails (nationalinsurance,userid,forename,middlename,surname,housenumber,street,towncity,postcode,suffix) VALUES ('" + nationalInsuranceInputBox.Text + "','"+"LAST_INSERT_ID()"+"','" + forenameInputBox.Text + "','" + middleNameInputBox.Text + "','" + surnameInputBox.Text + "','" + houseNumberInputBox.Text + "','" + streetTextBox.Text + "','" + towncityTextBox.Text + "','" + postcodeInputBox.Text + "','" + suffixComboBox.Text+"');";
//This is MySqlConnection here i have created the object and pass my connection string.
MySqlConnection MyConn2 = new MySqlConnection(MyConnection2);
//This is command class which will handle the query and connection object.
MySqlCommand MyCommand2 = new MySqlCommand(Query2, MyConn2);
MySqlCommand MyCommand3 = new MySqlCommand(Query3, MyConn2);
MySqlCommand MyCommand4 = new MySqlCommand(Query4, MyConn2);
MySqlDataReader MyReader2;
MySqlDataReader MyReader3;
MySqlDataReader MyReader4;
// opens new connection to database then executes command
MyConn2.Open();
MyReader2 = MyCommand2.ExecuteReader(); // Here the query will be executed and data saved into the database.
while (MyReader2.Read())
{
}
MyConn2.Close();
// opens new connection to database then executes command
MyConn2.Open();
MyReader3 = MyCommand3.ExecuteReader();
while (MyReader3.Read())
{
}
MyConn2.Close();
//opens new connection to database the exexcutes command
MyConn2.Open();
MyReader4 = MyCommand4.ExecuteReader();
while (MyReader4.Read())
{
}
MyConn2.Close();
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
MessageBox.Show("Hello " + forename + surname, "read and accept the terms and conditions to continue");
//new termsAndConditionsPage().Show();
//Hide();
}
As explained in other answer, you have the LAST_INSERT_ID between single quotes and this transform it in a literal string not in a statement to execute. However also removing the quotes I am not sure that you can retrieve the LAST_INSERT_ID using a connection different from the one that originates the AUTOINCREMENT number on the login table. In any case you should use a different approach and, as a first thing, you should remove ASAP the string concatenations and use parameters (Reason: Sql Injection or SurName = O'Neill)
string Query2 = "INSERT INTO vote (username) VALUE (#uname)";
string Query3 = #"INSERT INTO login (username,upassword) VALUE (#uname, #upass);
SELECT LAST_INSERT_ID();";
string Query4 = #"INSERT INTO userdetails
(nationalinsurance,userid,forename,middlename,
surname,housenumber,street,towncity,postcode,suffix)
VALUES (#insurance, #userid, #forename, #middlename,
#surname, #housenum, #street, #town, #postcode, #suffix)";
Now open just one connection and build three commands, all between an using statement
using(MySqlConnection con = new MySqlConnection(.....constring here....))
using(MySqlCommand cmd2 = new MySqlCommand(Query2, con))
using(MySqlCommand cmd3 = new MySqlCommand(Query3, con))
using(MySqlCommand cmd4 = new MySqlCommand(Query4, con))
{
con.Open();
// Add the parameter to the first command
cmd2.Parameters.Add("#uname", MySqlDbType.VarChar).Value = usernameInputBox.Text;
// run the first command
cmd2.ExecuteNonQuery();
// Add parameters to the second command
cmd3.Parameters.Add("#uname", MySqlDbType.VarChar).Value = usernameInputBox.Text;
cmd3.Parameters.Add("#upass", MySqlDbType.VarChar).Value = passwordInputBox.Text;
// Run the second command, but this one
// contains two statement, the first inserts, the
// second returns the LAST_INSERT_ID on that table, we need to
// catch that single return
int userID = (int)cmd3.ExecuteScalar();
// Run the third command
// but first prepare the parameters
cmd4.Parameters.Add("#insurance", MySqlDbType.VarChar).Value = nationalInsuranceInputBox.Text;
cmd4.Parameters.Add("#userid", MySqlDbType.Int32).Value = userID;
.... and so on for all other parameters
.... using the appropriate MySqlDbType for the column type
cmd4.ExecuteNonQuery();
}
you current query has an error
string Query4 = "INSERT INTO userdetails (nationalinsurance,userid,forename,middlename,surname,housenumber,street,towncity,postcode,suffix) VALUE ('" + nationalInsuranceInputBox.Text + "','"+"LAST_INSERT_ID()"+"','" + forenameInputBox.Text + "','" + middleNameInputBox.Text + "','" + surnameInputBox.Text + "','" + houseNumberInputBox.Text + "','" + streetTextBox.Text + "','" + towncityTextBox.Text + "','" + postcodeInputBox.Text + "','" + suffixComboBox.Text + "');SELECT LAST_INSERT_ID();"
try the attached query
In your text query string you have: "','"+"LAST_INSERT_ID()"+"','". Note that the "','"s before and after the "LAST_INSERT_ID()" are incorrectly enclosing the LAST_INSERT_ID() term in single quotes.
Try the following query:
string Query4 = "INSERT INTO userdetails (nationalinsurance,userid,forename,middlename,surname,housenumber,street,towncity,postcode,suffix) VALUE ('" + nationalInsuranceInputBox.Text + "',"+"LAST_INSERT_ID()"+",'" + forenameInputBox.Text + "','" + middleNameInputBox.Text + "','" + surnameInputBox.Text + "','" + houseNumberInputBox.Text + "','" + streetTextBox.Text + "','" + towncityTextBox.Text + "','" + postcodeInputBox.Text + "','" + suffixComboBox.Text + "');";
Error image is here
the error is in query line , its shows syntax error
try
{
string zero = "0";
DateTime dat = this.dateTimePicker1.Value.Date;
connection1.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = connection1;
command.CommandText = "insert into client_table(CLIENT, DATE,BILL_AMOUNT, PAID_AMOUNT, BALANCE, CONTACT, ADDRESS )VALUES ('" + txt_client.Text + "', #" + dat.ToLongDateString() + "# ,'" + zero + "','" + zero + "','" + zero + "','" + txt_contact.Text + "','" + txt_address.Text + "')";
command.ExecuteNonQuery();
connection1.Close();
MessageBox.Show("New Client Registration done Successfully.");
connection1.Dispose();
this.Hide();
employee_form f1 = new employee_form("");
f1.ShowDialog();
}
thank you in advance
In Access, dates are delimited by #, not '. Also, Access does not recognize the long date format. But dates are not stored in any format so no worries, change it to:
... + "', #" + dat.ToString() + "# ...etc.
Although if you do not parameterize your query serious damage or data exposure can be done through SQL Injection because someone could type in a SQL statement into one of those textboxes that you are implicitly trusting.
Working example:
class Program
{
static void Main(string[] args)
{
System.Data.OleDb.OleDbConnectionStringBuilder bldr = new System.Data.OleDb.OleDbConnectionStringBuilder();
bldr.DataSource = #"C:\Users\tekhe\Documents\Database2.mdb";
bldr.Provider = "Microsoft.Jet.OLEDB.4.0";
using (System.Data.OleDb.OleDbConnection cnxn = new System.Data.OleDb.OleDbConnection(bldr.ConnectionString))
{
cnxn.Open();
Console.WriteLine("open");
using (System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand())
{
cmd.Connection = cnxn;
cmd.CommandType = System.Data.CommandType.Text;
cmd.CommandText = "INSERT INTO [Table1] ([Dob]) VALUES(#" + DateTime.Now.ToString() + "#)";
cmd.ExecuteNonQuery();
}
}
Console.ReadKey();
}
}
Update
However, you want to do something more like this which uses Parameters to protect against SQL Injection which is extremely easy to exploit so do not think that you don't really need to worry about it:
static void Main(string[] args)
{
OleDbConnectionStringBuilder bldr = new OleDbConnectionStringBuilder();
bldr.DataSource = #"C:\Users\tekhe\Documents\Database2.mdb";
bldr.Provider = "Microsoft.Jet.OLEDB.4.0";
using (System.Data.OleDb.OleDbConnection cnxn = new OleDbConnection(bldr.ConnectionString))
{
cnxn.Open();
Console.WriteLine("open");
using (System.Data.OleDb.OleDbCommand cmd = new OleDbCommand())
{
cmd.Connection = cnxn;
cmd.CommandType = System.Data.CommandType.Text;
OleDbParameter dobParam = new OleDbParameter("#dob", OleDbType.Date);
dobParam.Value = DateTime.Now;
cmd.Parameters.Add(dobParam);
cmd.CommandText = "INSERT INTO [Table1] ([Dob]) VALUES(#dob)";
cmd.ExecuteNonQuery();
}
}
Console.ReadKey();
}
//code to write date in the access table.
string zero = "0";
DateTime dat = this.dateTimePicker1.Value.Date;
//MessageBox.Show(dat.ToShortDateString());
connection1.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = connection1;
//command.CommandText = "insert into client_table(DATEE) values( '"dat.ToShortDateString()+"')";
command.CommandText = "insert into client_table (CLIENT, DATEE, BILL_AMOUNT, PAID_AMOUNT, BALANCE, CONTACT, ADDRESS )VALUES ('" + txt_client.Text + "', #"+dat.ToShortDateString()+"# ,'" + zero + "','" + zero + "','" + zero + "','" + txt_contact.Text + "','" + txt_address.Text + "')";
command.ExecuteNonQuery();
connection1.Close();
MessageBox.Show("New Client Registration done Successfully.");
connection1.Dispose();
//New code for receiving the date between two range of dates
try
{
DateTime dat = this.dateTimePicker1.Value.Date;
DateTime dat2 = this.dateTimePicker2.Value.Date;
// MessageBox.Show(dat.ToShortDateString() + " " + dat2.ToShortDateString());
connection1.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = connection1;
string query;
query = "select * from client_table Where DATEE Between #" + dat.ToLongDateString() +"# and #" + dat2.ToLongDateString() + "# ";
command.CommandText = query;
OleDbDataAdapter da = new OleDbDataAdapter(command);
DataTable dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;
connection1.Close();
}
catch (Exception ex)
{
MessageBox.Show("Error" + ex);
}
Thank you all of you for the support.
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i'm a student in a vocational highschool and a newbie programmer..
i have some problem with using loop in my insert query..
i have two table, Book and Book_detail, wich link with foreign key, and i want to save data to both table, and the problem is every time i add a book, i have a textbox named copies_txt, the idea is i want to save the same book_id and the same location_id in the book_detail table but with diffrent boookdetail_id as much as the amount i insert in copies_txt.. and to achieve that i try using for loop, but i gives me error
duplicate entry for key Primary
, here's my full code
int copies = Convert.ToInt32(copies_txt.Text);
int i;
string constring = "datasource=localhost;port=3306;username=root;password=root";
string Query = "insert into simbada_perpustakaan.book(book_id,title,release_date,genre,author,copies,create_by,create_date) values ('" + this.book_id.Text + "','" + this.title_txt.Text + "','" + this.time.Text + "','" + this.genre_txt.Text + "','" + this.author_txt.Text + "','" + this.copies_txt.Text + "','" + this.username_lbl.Text + "','" + DateTime.Now.ToString("yyyy/MM/dd/hh/mm/ss") + "') ; ";
string Query2 = "insert into simbada_perpustakaan.book_detail(id_bookdetail,book_id,location_id) values('" + Guid.NewGuid() + "','" + this.book_id.Text + "','" + this.textBox1.Text + "') on duplicate key update id_bookdetail=(id_bookdetail=('"+Guid.NewGuid()+"'))";
MySqlConnection conDataBase = new MySqlConnection(constring);
MySqlCommand cmdDataBase = new MySqlCommand(Query, conDataBase);
MySqlCommand cmdDataBase2 = new MySqlCommand(Query2, conDataBase);
MySqlDataReader myReader;
try
{
conDataBase.Open();
myReader = cmdDataBase.ExecuteReader();
conDataBase.Close();
for (i = 0; i <= copies; i++)
{
conDataBase.Open();
myReader = cmdDataBase2.ExecuteReader();
conDataBase.Close();
}
MessageBox.Show("saved");
while (myReader.Read())
{
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
can somebody please point out my mistake... thanks before.
I think your issue is with the second query. Move the query inside the loop and check. Also you don't need a data reader since it's a select statement. Also you can avoid multiple database open and close statement. Try below code
int copies = Convert.ToInt32(copies_txt.Text);
int i;
string constring = "datasource=localhost;port=3306;username=root;password=root";
string Query = "insert into simbada_perpustakaan.book(book_id,title,release_date,genre,author,copies,create_by,create_date) values ('" + this.book_id.Text + "','" + this.title_txt.Text + "','" + this.time.Text + "','" + this.genre_txt.Text + "','" + this.author_txt.Text + "','" + this.copies_txt.Text + "','" + this.username_lbl.Text + "','" + DateTime.Now.ToString("yyyy/MM/dd/hh/mm/ss") + "') ; ";
MySqlConnection conDataBase = new MySqlConnection(constring);
MySqlCommand cmdDataBase = new MySqlCommand(Query, conDataBase);
MySqlDataReader myReader;
try
{
conDataBase.Open();
cmdDataBase.ExecuteNonquery();
for (i = 0; i <= copies; i++)
{
string a = Guid.NewGuid().ToString();
string Query2 = "insert into simbada_perpustakaan.book_detail(id_bookdetail,book_id,location_id) values('" + a + "','" + this.book_id.Text + "','" + this.textBox1.Text + "') on duplicate key update id_bookdetail=(id_bookdetail=('"+a+"'))";
MySqlCommand cmdDataBase2 = new MySqlCommand(Query2, conDataBase);
cmdDataBase2.ExecuteNonQuery();
}
MessageBox.Show("saved");
conDataBase.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
Also always try to do parameterized query. That can avoid sql injection problem.
Let,
first Guid.NewGuid() = 'zxcvbnm'
second Giud.NewGuid() = 'asdfghjkl'
book_id = 2
location_id = 3
After executing Query2 we get the string like
insert into book_detail(id_bookdetail,book_id,location_id) values('zxcvbnm','2'
,'3') on duplicate key update id_bookdetail='asdfghjkl';
when we try to execute it at for loop then
When i = 0
It inserts data fine as id_bookdetail('zxcvbnm') is unique.
When i = 1
It also inserts data fine because id_bookdetail('zxcvbnm') is used ago but using on duplicate key id_bookdetail set a new value('asdfghjkl') which is unique.
But When i = 2
It gives you error because first he gets id_bookdetaidid('zxvbnm') as duplicate, then he try to use second one('asdfghjkl') which is also duplicate. So it gives you that error.