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Stop Upload when a some data already exists

I have an upload button that can upload excel file and save it to my database. What I want to happen is that if there's one or more data in that excel file that already existing the other data will also not be uploaded though it's not yet existing. My code for adding it to the database and upload button are below.
Add to database
private void AddNewTrainee(string strdelname, string strrank, string strcomp, string strcourse, string strcenter, string strinst,
string strsdate, string stredate, string strcissued, string strcnumber, string strremark, int recdeleted, string credate, string update, int fromupload)
{
connection.Open();
String checkDateAndName = "Select count(*) from Trainees where StartDate= '" + strsdate + "' and Delegate='" + strdelname + "' and REC_DELETED = 0 ";
SqlCommand cmd = new SqlCommand(checkDateAndName, connection);
int dataRepeated = Convert.ToInt32(cmd.ExecuteScalar().ToString());
bool boolDataRepated;
connection.Close();
if (!(dataRepeated >= 1))
{
boolDataRepated = false;
}
else
boolDataRepated = true;
connection.Open();
string certNumber = "Select * from CertID_Table update CertID_Table set CertificateID = CertificateID + 1 from CertID_Table ";
SqlCommand cmdCert = new SqlCommand(certNumber, connection);
using (SqlDataReader oReader = cmdCert.ExecuteReader())
{
while (oReader.Read())
{
string test1 = oReader["CertificateID"].ToString();
ViewState["certnumber"] = test1;
}
}
connection.Close();
strcnumber = (string)ViewState["certnumber"];
if (boolDataRepated == false)
{
string path = "D:\\Intern\\BASSWeb\\SQLCommands\\AddSQL.txt";
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(path))
{
while (sr.Peek() >= 0)
{
sb.Append(sr.ReadLine());
}
string sql = sb.ToString();
try
{
connection.Open();
SqlCommand cmd1 = new SqlCommand(sql, connection);
cmd1.Parameters.AddWithValue("#delName", strdelname);
cmd1.Parameters.AddWithValue("#rank", strrank);
cmd1.Parameters.AddWithValue("#comp", strcomp);
cmd1.Parameters.AddWithValue("#course", strcourse);
cmd1.Parameters.AddWithValue("#center", strcenter);
cmd1.Parameters.AddWithValue("#instructor", strinst);
cmd1.Parameters.AddWithValue("#sdate", strsdate);
cmd1.Parameters.AddWithValue("#edate", stredate);
cmd1.Parameters.AddWithValue("#cissued", strcissued);
cmd1.Parameters.AddWithValue("#cnumber", strcnumber);
cmd1.Parameters.AddWithValue("#remark", strremark);
cmd1.Parameters.AddWithValue("#rdeleted", recdeleted);
cmd1.Parameters.AddWithValue("#cdate", credate);
cmd1.Parameters.AddWithValue("#udate", update);
cmd1.Parameters.AddWithValue("#fupload", fromupload);
cmd1.CommandType = CommandType.Text;
cmd1.ExecuteNonQuery();
}
catch (System.Data.SqlClient.SqlException ex)
{
string msg = "Insert/Update Error:";
msg += ex.Message;
throw new Exception(msg);
}
finally
{
connection.Close();
}
}
}
else
{
string script = "alert(\"The data already exists\");";
ScriptManager.RegisterStartupScript(this, GetType(), "ServerControlScript", script, true);
}
}
Upload Button
protected void btnUpload_Click(object sender, EventArgs e)
{
if (FileUpload1.HasFile)
{
try
{
string path = Path.GetFileName(FileUpload1.FileName);
path = path.Replace(" ", "");
FileUpload1.SaveAs(Server.MapPath("~/Datas/") + path);
String ExcelPath = Server.MapPath("~/Datas/") + path;
OleDbConnection mycon = new OleDbConnection("Provider = Microsoft.ACE.OLEDB.12.0; Data Source = " + ExcelPath + "; Extended Properties=Excel 8.0; Persist Security Info = False");
mycon.Open();
OleDbCommand cmdX = new OleDbCommand("select * from [Sheet1$]", mycon);
OleDbDataReader dr = cmdX.ExecuteReader();
while (dr.Read())
{
delegateName = dr[0].ToString();
rankPos = dr[1].ToString();
company = dr[2].ToString();
courseTitle = dr[3].ToString();
trainingCenter = dr[4].ToString();
instructor = dr[5].ToString();
staDa = DateTime.Parse(dr[6].ToString());
string startDate = staDa.ToString("MM/dd/yyyy");
endDa = DateTime.Parse(dr[7].ToString());
string endDate = endDa.ToString("MM/dd/yyyy");
certIssued = dr[8].ToString();
certNum = dr[9].ToString();
remarks = dr[10].ToString();
recDeleted = 0;
dateCreated = DateTime.Now.ToString("MM/dd/yyyy HH:mm");
dateUpdated = string.Empty;
fromUpload = 1;
AddNewTrainee(delegateName, rankPos, company, courseTitle, trainingCenter, instructor,
startDate, endDate, certIssued, certNum, remarks, recDeleted, dateCreated, dateUpdated, fromUpload);
}
}
catch (Exception ex)
{
string errorMessage = "alert(\"ERROR: " + ex.Message.ToString() + " \");";
ScriptManager.RegisterStartupScript(this, GetType(), "ServerControlScript", errorMessage, true);
}
}
else
{
string errorMessage = "alert(\"ERROR: You have not specified a file \");";
ScriptManager.RegisterStartupScript(this, GetType(), "ServerControlScript", errorMessage, true);
}
PopulateData();
}

You have to set the transferMode to 'Streamed', otherwise you will always get one file.
Have a look at this article: https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/how-to-enable-streaming

I think there is a few things you'll need to tackle to reach your end goal.
Use a multiselect method and a get a post list of all files required
for upload.
Do your processing requirements in a Transaction
When your done processing, commit or rollback the transaction as necessary and keep the data you want.
Study the link I posted a little bit. At first transaction seem a little bit overwhelming, but they are actually very simple. Maybe I can help you get started in your understandings. There are really only three extra steps;
1.
Initialize a transaction object after you create a command.
SqlTransaction transaction = connection.BeginTransaction();
2.
On all of your Sql Commands (Inserts,updates, deletes ect) attach the transaction.
cmd.Transaction = transaction;
This will allow you to Execute the SqlCommands without actually putting them into your database. Lastly, when you've processed all of your inserts and updates you can do the final step. The using statement is not required, just good practice. That could be the next thing you'll want to understand it is very helpful.
3.
Commit all SqlCommands to the database.
transaction.Commit();
If at any point during your data processing, something goes wrong than you can rollback every transaction like this.
transaction.Rollback();

c# mysql unable to output query to a textbox

here is my code:
private void searchInDatabase()
{
MySqlConnection c = new MySqlConnection("datasource=localhost; username=root; password=123456; port=3306");
MySqlCommand mcd;
MySqlDataReader mdr;
String query;
try
{
c.Open();
query = "SELECT * FROM test.classmates WHERE first_name ='"+searchName.Text+"'";
mcd = new MySqlCommand(query, c);
mdr = mcd.ExecuteReader();
if(mdr.Read())
{
firstName.Text = mdr.GetString("first_name");
middleName.Text = mdr.GetString("middle_name");
lastName.Text = mdr.GetString("last_name");
age.Text = mdr.GetString("age");
}
else
{
MessageBox.Show("Result Not Found");
}
}
catch(Exception error)
{
MessageBox.Show("Error: "+error.Message);
}
finally
{
c.Close();
}
}
I would like to ask for a help if I have missed on anything or I am doing it wrong. If you have free time, I will much appreciate it if you will comment the perfect way to do I implement this problem: I want to get data from MySQL then put it in a textbox.

According to MSDN you need to pass the column number as parameter
public override string GetString(int i)
So try to pass the column number (starts from 0) of your column name. Assuming the first_name is the first column of your table then
firstName.Text = mdr.GetString(0);
UPDATE
Try to use MySqlConnectionStringBuilder
MySqlConnectionStringBuilder conn_string = new MySqlConnectionStringBuilder();
conn_string.Server = "serverip/localhost";
conn_string.UserID = "my_user";
conn_string.Password = "password";
conn_string.Database = "my_db";
MySqlConnection conn = new MySqlConnection(conn_string.ToString();

First of all look at this sample of connection string and change your connection string:
'Server=myServerAddress;Port=1234;Database=myDataBase;Uid=myUsername;Pwd=myPasswor;'
If connection is OK send erorr message or full exception.

Efficient Way to Update a lot of Rows from C#

I have a program where I open a SqlConnection, load up a list of objects, modify a value on each object, then update the rows in the SQL Server database. Because the modification requires string parsing I wasn't able to do with with purely T-SQL.
Right now I am looping through the list of objects, and running a SQL update in each iteration. This seems inefficient and I'm wondering if there is a more efficient way to do it using LINQ
The list is called UsageRecords. The value I'm updating is MthlyConsumption.
Here is my code:
foreach (var item in UsageRecords)
{
string UpdateQuery = #"UPDATE tbl810CTImport
SET MthlyConsumption = " + item.MthlyConsumption +
"WHERE ID = " + item.Id;
SqlCommand update = new SqlCommand(UpdateQuery, sourceConnection);
update.ExecuteNonQuery();
}

Try this instead:
string UpdateQuery = #"UPDATE tbl810CTImport SET MthlyConsumption = #consumption WHERE ID = #itemId";
var update = new SqlCommand(UpdateQuery, sourceConnection);
update.Parameters.Add("#consumption", SqlDbType.Int); // Specify the correct types here
update.Parameters.Add("#itemId", SqlDbType.Int); // Specify the correct types here
foreach (var item in UsageRecords)
{
update.Parameters[0].Value = item.MthlyConsumption;
update.Parameters[1].Value = item.Id;
update.ExecuteNonQuery();
}
It should be faster because:
You don't have to create the command each time.
You don't create a new string each time (concatenation)
The query is not parsed at every iteration (Just changes the parameters values).
And it will cache the execution plan. (Thanks to #JohnCarpenter from the comment)

You can either use
SqlDataAdapter - See How to perform batch update in Sql through C# code
or what I have previously done was one of the following:
Tear down the ID's in question, and re-bulkinsert
or
Bulk Insert the ID + new value into a staging table, and update the table on SQL server:
update u
set u.MthlyConsumption = s.MthlyConsumption
from tbl810CTImport u
inner join staging s on
u.id = s.id

In a situation like this, where you can't write a single update statement to cover all your bases, it's a good idea to batch up your statements and run more than one at a time.
var commandSB = new StringBuilder();
int batchCount = 0;
using (var updateCommand = sourceConnection.CreateCommand())
{
foreach (var item in UsageRecords)
{
commandSB.AppendFormat(#"
UPDATE tbl810CTImport
SET MthlyConsumption = #MthlyConsumption{0}
WHERE ID = #ID{0}",
batchCount
);
updateCommand.Parameters.AddWithValue(
"#MthlyConsumption" + batchCount,
item.MthlyConsumption
);
updateCommand.Parameters.AddWithValue(
"#ID" + batchCount,
item.MthlyConsumption
);
if (batchCount == 500) {
updateCommand.CommandText = commandSB.ToString();
updateCommand.ExecuteNonQuery();
commandSB.Clear();
updateCommand.Parameters.Clear();
batchCount = 0;
}
else {
batchCount++;
}
}
if (batchCount != 0) {
updateCommand.ExecuteNonQuery();
}
}

It should be as simple as this . . .
private void button1_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("Server=YourServerName;Database=YourDataBaseName;Trusted_Connection=True");
try
{
//cmd new SqlCommand( "UPDATE Stocks
//SET Name = #Name, City = #cit Where FirstName = #fn and LastName = #add";
cmd = new SqlCommand("Update Stocks set Ask=#Ask, Bid=#Bid, PreviousClose=#PreviousClose, CurrentOpen=#CurrentOpen Where Name=#Name", con);
cmd.Parameters.AddWithValue("#Name", textBox1.Text);
cmd.Parameters.AddWithValue("#Ask", textBox2.Text);
cmd.Parameters.AddWithValue("#Bid", textBox3.Text);
cmd.Parameters.AddWithValue("#PreviousClose", textBox4.Text);
cmd.Parameters.AddWithValue("#CurrentOpen", textBox5.Text);
con.Open();
int a = cmd.ExecuteNonQuery();
if (a > 0)
{
MessageBox.Show("Data Updated");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
con.Close();
}
}
Change the code to suit your needs.

Show messages according to the MySQL database data? C#

I want to get the values from MySQL database and that would need to show the messages according to values. But it does not happen and that will always show int privilege is 0. If I did not assign that default value, errors will be showing on the code.
How can I solve this issue and show messages according to the int privilege values?
private void button_login_Click(object sender, RoutedEventArgs e)
{
string username = usernameInput.Text;
string password = passwordInput.Password;
int privilege = 0;
try
{
//This is command class which will handle the query and connection object.
string Query = "SELECT`tbl_user_login`.`u_id`,`tbl_user_login`.`u_username`,
`tbl_user_login`.`u_password`,`tbl_user_login`.`u_privilege`
FROM `bcasdb`.`tbl_user_login`WHERE `tbl_user_login`.`u_username` = '"
+ username + "' AND `tbl_user_login`.`u_password` ='" + password
+ "' AND `tbl_user_login`.`u_privilege` = #privi;";
MySqlConnection conn =
new MySqlConnection(BCASApp.DataModel.DB_CON.connection);
MySqlCommand cmd = new MySqlCommand(Query, conn);
cmd.Parameters.AddWithValue("#privi", privilege);
MySqlDataReader MyReader;
conn.Open();
MyReader = cmd.ExecuteReader();
// Here our query will be executed and data saved into the database.
if (MyReader.HasRows && this.Frame != null)
{
while (MyReader.Read())
{
if (privilege == 1)
{
DisplayMsgBox("click ok to open the admin page ", "OK");
}
if (privilege == 2)
{
DisplayMsgBox("click ok to open the staff page ", "OK");
}
else
{
DisplayMsgBox("privilege 0", "ok");
}
}
}
else
{
DisplayMsgBox("sucess else", "ok");
}
conn.Close();
}
catch (Exception )
{
DisplayMsgBox("sucess catch", "ok");
}
}

Looks like what you're trying to do is checking the value of u_privilege column from tbl_user_login table instead of making a where condition based on privilege. You need to remove this where condition
AND `tbl_user_login`.`u_privilege` = #privi
and also remove the parameter assignment
cmd.Parameters.AddWithValue("#privi", privilege);
You can get the value of tbl_user_login.u_privilege by using MySqlDataReader.GetInt32 syntax inside while (MyReader.Read()) block
MyReader.GetInt32(3)
Please note that 3 is used because MyReader.GetInt32 requires a zero based index parameter and tbl_user_login.u_privilege is the fourth column from your query. The value should be assigned to privilege variable as below
privilege = MyReader.GetInt32(3)
On a side note, you should parameterize your query to avoid SQL injection. Here's the complete code after implementing the above changes
int privilege = 0;
try
{
//This is command class which will handle the query and connection object.
string Query = "SELECT`tbl_user_login`.`u_id`,`tbl_user_login`.`u_username`,
`tbl_user_login`.`u_password`,`tbl_user_login`.`u_privilege`
FROM `bcasdb`.`tbl_user_login`WHERE `tbl_user_login`.`u_username` =
#username AND `tbl_user_login`.`u_password` = #password;";
MySqlConnection conn =
new MySqlConnection(BCASApp.DataModel.DB_CON.connection);
MySqlCommand cmd = new MySqlCommand(Query, conn);
cmd.Parameters.AddWithValue("#username", username);
cmd.Parameters.AddWithValue("#password", password);
MySqlDataReader MyReader;
conn.Open();
MyReader = cmd.ExecuteReader();
// Here our query will be executed and data saved into the database.
if (MyReader.HasRows && this.Frame != null)
{
while (MyReader.Read())
{
privilege = MyReader.GetInt32(3)
if (privilege == 1)
{
DisplayMsgBox("click ok to open the admin page ", "OK");
}
if (privilege == 2)
{
DisplayMsgBox("click ok to open the staff page ", "OK");
}
else
{
DisplayMsgBox("privilege 0", "ok");
}
}
}
else
{
DisplayMsgBox("sucess else", "ok");
}
conn.Close();
}
catch (Exception )
{
DisplayMsgBox("sucess catch", "ok");
}

If im not wrong, the privilege is being returned as a string type. Try take it in as a string then cast it to an integer?

C# Fatal error encoutered during data read

I'm selecting about 20,000 records from the database and then I update them one by one.
I looked for this error and I saw that setting the CommandTimeout will help, but not in my case.
public void Initialize()
{
MySqlConnectionStringBuilder SQLConnect = new MySqlConnectionStringBuilder();
SQLConnect.Server = SQLServer;
SQLConnect.UserID = SQLUser;
SQLConnect.Password = SQLPassword;
SQLConnect.Database = SQLDatabase;
SQLConnect.Port = SQLPort;
SQLConnection = new MySqlConnection(SQLConnect.ToString());
}
public MySqlDataReader SQL_Query(string query)
{
MySqlCommand sql_command;
sql_command = SQLConnection.CreateCommand();
sql_command.CommandTimeout = int.MaxValue;
sql_command.CommandText = query;
MySqlDataReader query_result = sql_command.ExecuteReader();
return query_result;
}
public void SQL_NonQuery(string query)
{
MySqlCommand sql_command;
sql_command = SQLConnection.CreateCommand();
sql_command.CommandTimeout = int.MaxValue;
sql_command.CommandText = query;
sql_command.ExecuteNonQuery();
}
And here is my method which makes the select query:
public void CleanRecords()
{
SQLActions.Initialize();
SQLActions.SQL_Open();
MySqlDataReader cashData = SQLActions.SQL_Query("SELECT `cash`.`id`, SUM(`cash`.`income_money`) AS `income_money`, `cash_data`.`total` FROM `cash_data` JOIN `cash` ON `cash`.`cash_data_id` = `cash_data`.`id` WHERE `user`='0' AND `cash_data`.`paymentterm_id`='0' OR `cash_data`.`paymentterm_id`='1' GROUP BY `cash_data_id`");
while(cashData.Read()){
if(cashData["income_money"].ToString() == cashData["total"].ToString()){
UpdateRecords(cashData["id"].ToString());
}
}
SQLActions.SQL_Close();
}
And here is the method which makes the update:
public void UpdateRecords(string rowID)
{
SQLActions.Initialize();
SQLActions.SQL_Open();
SQLActions.SQL_NonQuery("UPDATE `cash_data` SET `end_date`='" + GetMeDate() + "', `user`='1' WHERE `id`='" + rowID + "'");
SQLActions.SQL_Close();
}
Changing the database structure is not an option for me.
I thought that setting the timeout to the maxvalue of int will solve my problem, but is looks like this wont work in my case.
Any ideas? :)
EDIT:
The error which I get is "Fatal error encoutered during data read".
UPDATE:
public void CleanRecords()
{
StringBuilder dataForUpdate = new StringBuilder();
string delimiter = "";
SQLActions.Initialize();
SQLActions.SQL_Open();
MySqlDataReader cashData = SQLActions.SQL_Query("SELECT `cash`.`id`, SUM(`cash`.`income_money`) AS `income_money`, `cash_data`.`total` FROM `cash_data` JOIN `cash` ON `cash`.`cash_data_id` = `cash_data`.`id` WHERE `user`='0' AND `cash_data`.`paymentterm_id`='0' OR `cash_data`.`paymentterm_id`='1' GROUP BY `cash_data_id`");
while (cashData.Read())
{
if (cashData["income_money"].ToString() == cashData["total"].ToString())
{
dataForUpdate.Append(delimiter);
dataForUpdate.Append("'" + cashData["id"].ToString() + "'");
delimiter = ",";
}
}
SQLActions.SQL_Close();
UpdateRecords(dataForUpdate.ToString());
}
public void UpdateRecords(string rowID)
{
SQLActions.Initialize();
SQLActions.SQL_Open();
SQLActions.SQL_NonQuery("UPDATE `cash_data` SET `end_date`='" + GetMeDate() + "', `user`='1' WHERE `id` IN (" + rowID + ")");
SQLActions.SQL_Close();
}

You may be able to use
UPDATE cash_data .... WHERE id IN (SELECT ....)
and do everything in one go. Otherwise, you could do it in two steps: first the select collects all the ids, close the connection and then do the update in obne go with all the ids.
The code for the second option might look something like this:
public void CleanRecords()
{
StringBuilder builder = new StringBuilder();
string delimiter = "";
SQLActions.Initialize();
SQLActions.SQL_Open();
MySqlDataReader cashData = SQLActions.SQL_Query("SELECT `cash`.`id`, SUM(`cash`.`income_money`) AS `income_money`, `cash_data`.`total` FROM `cash_data` JOIN `cash` ON `cash`.`cash_data_id` = `cash_data`.`id` WHERE `user`='0' AND `cash_data`.`paymentterm_id`='0' OR `cash_data`.`paymentterm_id`='1' GROUP BY `cash_data_id`");
while(cashData.Read()){
if(cashData["income_money"].ToString() == cashData["total"].ToString()){
builder.Append(delimiter);
builder.Append("'" + cashData["id"].ToString() + "'");
delimiter = ",";
}
}
SQLActions.SQL_Close();
UpdateRecords(builder.ToString());
}
public void UpdateRecords(string rowIDs)
{
SQLActions.Initialize();
SQLActions.SQL_Open();
SQLActions.SQL_NonQuery("UPDATE `cash_data` SET `end_date`='" + GetMeDate() + "', `user`='1' WHERE `id` IN (" + rowIDs + ")";
SQLActions.SQL_Close();
}

There are multiple problem:
First: You have reading information around 20K using data reader and then doing update one by one in reader itself. Reader holds the connection open until you are finished. So this is not the good way to do it. Solution: We can read the information using Data Adapter.
Second: Rather than doing one by one update, we can update in bulk in one go. There are multiple option for bulk operation. In SQL u can do either by sending information in XML format or u can use Table Valued Parameter (TVP) (http://www.codeproject.com/Articles/22205/ADO-NET-and-OPENXML-to-Perform-Bulk-Database-Opera) OR (http://dev.mysql.com/doc/refman/5.5/en/load-xml.html)