I am trying to insert data into MYSQL database using Asp.Net but I am getting the following error message: Failed to connect to the database due to System.InvalidOperationsException.The connection must be valid and open.
Here is what I am doing:
protected void SU_Button_Click(object sender, EventArgs e)
{
string connectionString = #"Data Source=mno; Database=xyz; User ID=abc; Password=abc";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
try
{
string insertData = "insert into signup_table(firstname,surname,mobile_number,email_address,password," +
"confirm_password) values (#F_Name, #S_Name, #M_Number, #E_Address, #Password, #C_Password)";
MySqlCommand command = new MySqlCommand(insertData, connection);
command.Parameters.AddWithValue("#F_Name",FN_TextBox.Text);
command.Parameters.AddWithValue("#S_Name", SN_TextBox.Text);
command.Parameters.AddWithValue("#M_Number", MN_TextBox.Text);
command.Parameters.AddWithValue("#E_Address", EA_TextBox.Text);
command.Parameters.AddWithValue("#Password", P_TextBox.Text);
command.Parameters.AddWithValue("#C_Password", CP_TextBox.Text);
int result = command.ExecuteNonQuery();
connection.Open();
MessageBox.Show("Connected to database");
MessageBox.Show("Data inserted successfully");
}
catch(Exception ex)
{
MessageBox.Show("Failed to connect to database due to" + ex.ToString());
MessageBox.Show("Failed to insert data due to" + ex.ToString());
}
}
}
Please suggest something. Thanks in advance... :)
You have to open your connection before you execute the query.
connection.Open();
int result = command.ExecuteNonQuery();
also dont forget to close your connecion after you finished.
change this
int result = command.ExecuteNonQuery();
connection.Open();
to this
connection.Open();
int result = command.ExecuteNonQuery();
Related
I have a project and when I try to run it and the data test is big I have always a connection timeout.
I added "sqlCmd.CommandTimeout = 3600;" but still not working.
What could am I doing wrong?
This is my code:
public void createCode(String ce, int ord, String beh, int wkd)
{
String strSql = "";
SqlCommand sqlCmd;
SqlConnection conexion = new SqlConnection(getConexion());
try
{
if (conexion.State != ConnectionState.Open)
conexion.Open();
//The insert works fine in sql server
strSql = "Insert into x with values";
sqlCmd = new SqlCommand(strSql, conexion);
sqlCmd.CommandTimeout = 3600;
sqlCmd.ExecuteScalar();
}
catch (Exception ex)
{
throw new Exception("Error creating Code. " + ex.Message);
}
finally
{
if (conexion.State == ConnectionState.Open)
conexion.Close();
}
}
You might need to set transaction timeout in your config file, like so;
<system.transactions>
<defaultSettings timeout="01:00:00" />
</system.transactions>
sqlCmd.ExecuteScalar() is not correct for your script, try using sqlCmd.ExecuteNonQuery() instead and remove timeout.
sqlCmd = new SqlCommand(strSql, conexion);
sqlCmd.ExecuteNonQuery();
Check each function, ExecuteScalar tries to return first value from a select, while ExecuteNonQuery does not retrieve any value, just gets num of rows affected.
Hope it helps!
I'm new in C# and i would like to insert some Datagridview columns to Access in order to retrieve this data afterwards.
private void metroButton5_Click(object sender, EventArgs e)
try
{
OleDbConnection connection = new OleDbConnection(#"Provider = Microsoft.ACE.OLEDB.12.0; Data Source = F:\Database\DBAdatabase.accdb; Persist Security Info = False; ");
for (int s = 0; s < dataGridView1.Rows.Count - 1; s++)
{
OleDbCommand command = new OleDbCommand(#"INSERT INTO Quotations (Position, LVPosition)VALUES('"+dataGridView1.Rows[s].Cells[0].Value+"','"+dataGridView1.Rows[s].Cells[1].Value+"')", connection);
connection.Open();
command.Connection = connection;
command.ExecuteNonQuery();
MessageBox.Show("Data Saved");
connection.Close();
}
}
catch (Exception ex)
{
MessageBox.Show("Error " + ex);
}
I become the Error Systen.Data.OleDb.OleDbException (0x80040E14): Syntaxerror in the Insert Into.
Can somebody help me to solve it .....
Thx a lot..
I also referred to the this link (https://www.youtube.com/watch?v=8hCfje5VL-0&ab_channel=codefactory2016), but I cant find what's the error reason.
Off the bat, I would change
MessageBox.Show("Error " + ex);
to
MessageBox.Show("Error " + ex.Message);
It will give you a better understanding of the error
Also, it is very good practice to use parameters, this prevents single quote issues and prevents sql injection problems:
try
{
OleDbConnection connection = new OleDbConnection(#"Provider = Microsoft.ACE.OLEDB.12.0; Data Source = F:\Database\DBAdatabase.accdb; Persist Security Info = False; ");
OleDbCommand command = new OleDbCommand("", connection);
for (int s = 0; s < dataGridView1.Rows.Count - 1; s++)
{
command.Parameters.AddWithValue("#position",dataGridView1.Rows[s].Cells[0].Value);
command.Parameters.AddWithValue("#lvPosition",dataGridView1.Rows[s].Cells[1].Value);
command.CommandText = "INSERT INTO Quotations (Position, LVPosition) VALUES (#position, #lvPosition)";
connection.Open();
//this line is not needed as it is set in the command constructor above
//command.Connection = connection;
command.ExecuteNonQuery();
MessageBox.Show("Data Saved");
connection.Close();
//edit - this needs to run or you will have duplicate values inserted
command.Parameters.Clear();
}
}
catch (Exception ex)
{
MessageBox.Show("Error " + ex.Message);
}
Even still I would seriously look into using statements for the connection and command, and have a try catch around opening the connection. But that is getting a bit off topic
I want to create tables in SQL Server in my program. The code compiles and everything seems to be ok, but after I close it the tables don't appear in the SQL Server database.
EDITED
Please help here is the code and the connection string:
connectionString = "Driver={Sql Server}; Server=baxu\\sqlexpress; Database = baza1;" + $"UID ={ username };PWD={ password };";
Code:
try
{
using (OdbcCommand comm = new OdbcCommand())
{
comm.Connection = cnn;
comm.CommandText = cmdString;
comm.ExecuteNonQuery();
}
}
catch (Exception ex)
{
System.Windows.MessageBox.Show(ex.Message);
}
This here should work for you:
NB: If you dont use trusted connection - Then look at the different connectionstrings here:
var conn = new OdbcConnection();
conn.ConnectionString =
#"Driver={SQL Server};" +
#"Server=EGC25199\SQL2016;" +
#"DataBase=LegOgSpass;" +
#"Trusted_Connection=Yes;";
try
{
string cmdString = "CREATE TABLE dbo.odbctable (Wartosc int, Czas datetime)";
conn.Open();
using (OdbcCommand cmd = new OdbcCommand(cmdString, conn))
{
cmd.ExecuteNonQuery();
conn.Close();
}
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
This might help. I noticed you used an unassigned name in the create command.
using System;
using System.Data;
using System.Data.Odbc;
class CommandOdbcExample{
static void Main() {
OdbcConnection comm = new OdbcConnection(#"DSN=MyOdbcdDB");
OdbcCommand nonqueryCommand = comm.CreateCommand();
try {
comm.Open();
nonqueryCommand.CommandText = "CREATE TABLE MyTable (Wartosc int, Czas datetime)";
Console.WriteLine(nonqueryCommand.CommandText);
nonqueryCommand.ExecuteNonQuery();
}
catch (OdbcException ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
comm.Close();
Console.WriteLine("Connection Closed.");
}
}
}
I have this simple method that is supposed to insert a row into a DB. It is throwing an exception.
private void AddToLiveQueue(int user_id, bool release = false)
{
string sql = "INSERT INTO live_support_queues (user_id, release, created_at, updated_at)";
sql += " VALUES(?user_id, ?release, ?created_at, ?created_at)";
MySqlConnection conn = new MySqlConnection(connString);
MySqlCommand cmd = conn.CreateCommand();
cmd.CommandText = sql;
cmd.Parameters.AddWithValue("?user_id", user_id);
cmd.Parameters.AddWithValue("?release", release);
cmd.Parameters.AddWithValue("?created_at", DateTime.UtcNow);
try
{
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
}
catch (Exception ex)
{
SendEmail email = new SendEmail();
email.Send(ex.Message + " " + ex.ToString());
}
}
I am getting this error:
"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 'release, created_at, updated_at) VALUES(70, 0, '2017-09-22 23:00:16.686741', '20' at line 1"
Any help is greatly appreciated. Thanks!
release is a reserved word, and needs escaped with ` symbols if used as an identifier.
https://dev.mysql.com/doc/refman/5.7/en/keywords.html
i'm having an issue using C# inserting multiple rows into a MySQL database, have the following code;
//Upload to mysql
string connStr = "server=server;user=username;database=databasae;port=3306;password=password;";
MySqlConnection conn = new MySqlConnection(connStr);
conn.Open();
foreach (Channel chan in results)
{
// Perform databse operations
try
{
//Create sql statment with parameters
string sql = "INSERT INTO channels(ID, Name) VALUES (#id,#name)";
MySqlCommand cmd = new MySqlCommand(sql, conn);
cmd.Parameters.AddWithValue("#id", chan.ID);
cmd.Parameters.AddWithValue("#name", chan.Name);
cmd.ExecuteNonQuery();
updateStatus("Inserted");
}
catch (Exception ex)
{
updateStatus(ex.Message.ToString());
}
conn.Close();
I seem to be getting "connection must be valid and open". From what i can see i'm passing the connection string correctly and i'm using ExecuteNonQuery. And idea's?
thanks
conn.Close(); should be outside the foreach.
The following would work :
//Upload to mysql
string connStr = "server=server;user=username;database=databasae;port=3306;password=password;";
MySqlConnection conn = new MySqlConnection(connStr);
conn.Open();
foreach (Channel chan in results)
{
// Perform databse operations
try
{
//Create sql statment with parameters
string sql = "INSERT INTO channels(ID, Name) VALUES (#id,#name)";
MySqlCommand cmd = new MySqlCommand(sql, conn);
cmd.Parameters.AddWithValue("#id", chan.ID);
cmd.Parameters.AddWithValue("#name", chan.Name);
cmd.ExecuteNonQuery();
updateStatus("Inserted");
}
catch (Exception ex)
{
updateStatus(ex.Message.ToString());
}
}
conn.Close();
Looks like the connection is inside the foreach loop. It should be outside the foreach loop.
conn.Close(); should be outside the foreach loop.
How about using
using(MySqlConnection conn = new MySqlConnection(connStr))
{
//your stuff in here
}
This is transformed into a try final block .. so should take care of your connection woes.
add finally block to the try catch code and put conn.close() in it.like
finally
{
if(conn.ConnectionSTate=Connectionstate.open)
{
conn.close()
}
}