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Receiving an error when insert data into a .dbf file

Backgournd
I am currently working on a project which will need me to create a local .dbf file which I must then populate with a value. I am currently able to create a .dbf file in a test dir and adding a column to it, however when I later try to add a value to the column, it errors out.
Problem
I am currently not able to write to the column Public in the .dbf file which I created. When the code goes into ExecuteNonQuery();, it an error and is caught in my catch statement.
Working code
public static bool CreateDBF()
{
try
{
string dbfDirectory = #"c:\Users\me\Desktop\New911";
string connectionString = "Provider=VFPOLEDB;Data Source=" + dbfDirectory;
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
connection.Open();
OleDbCommand command = connection.CreateCommand();
command.CommandText = "create table CustomProperties(Public C(60))";
command.ExecuteNonQuery();
connection.Close();
InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
}
return true;
}
catch (Exception ex)
{
throw;
}
}
Working Code - appendix:
The above block of code successfully create the .dbf file with the column which I want as the following image will show
Not working code:
public static bool InsertDataIntoDBF(string path)
{
try
{
string strLogConnectionString = "Provider=VFPOLEDB;Data Source=" + path + ";Collating Sequence=machine;Mode=ReadWrite;";
string query = #"INSERT INTO CustomProperties (Public)";
using (OleDbConnection connection = new OleDbConnection(strLogConnectionString))
{
OleDbCommand command = new OleDbCommand(query, connection);
command.Parameters.AddWithValue("#Public", "True");
connection.Open();
new OleDbCommand("set null off", connection).ExecuteNonQuery();
command.ExecuteNonQuery();
connection.Close();
}
return true;
}
catch (Exception ex)
{
throw;
}
}
Updated code blocks
Working block:
public static bool CreateDBF()
{
try
{
string dbfDirectory = #"c:\Users\er4505\Desktop\New911";
string connectionString = "Provider=VFPOLEDB;Data Source=" + dbfDirectory;
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
connection.Open();
OleDbCommand command = connection.CreateCommand();
command.CommandText = "create table CustomProperties(Public C(60))";
command.ExecuteNonQuery();
connection.Close();
}
InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
return true;
}
catch (Exception ex)
{
string viewError = JsonConvert.SerializeObject(ex);
return false; << I have a breakpoint here
}
}
Non-working block:
public static bool InsertDataIntoDBF(string path)
{
try
{
string strLogConnectionString = "Provider=VFPOLEDB;Data Source=" + path + ";Collating Sequence=machine;Mode=ReadWrite;";
string query = #"INSERT INTO CustomProperties (Public) VALUES (#Public)";
using (OleDbConnection connection = new OleDbConnection(strLogConnectionString))
{
OleDbCommand command = new OleDbCommand(query, connection);
command.Parameters.AddWithValue("#Public", "True");
connection.Open();
command.ExecuteNonQuery();
connection.Close();
}
return true;
}
catch (Exception ex)
{
string viewError = JsonConvert.SerializeObject(ex);
return false; << breakpoint here
}
}
Error caught:
oledbErrors
Message: Syntax error.
NativeError: 0
Source: Microsoft OLE DB Provider for Visual FoxPro
ClassName: System.Data.OleDb.OleDbException
Message: Syntax error.

This works for me. Try it
static void Main(string[] args)
{
try
{
CreateDBF();
Console.WriteLine(ReadDB());
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
private static string dbfDirectory = #"c:\Test\dbTest";
private static string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbfDirectory + ";Extended Properties = dBase IV";
public static bool CreateDBF()
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
connection.Open();
OleDbCommand command = connection.CreateCommand();
command.CommandText = "Create Table CustomProperties ([Public] char(50))";
command.ExecuteNonQuery();
connection.Close();
}
InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
return true;
}
public static bool InsertDataIntoDBF(string path)
{
string query = #"INSERT INTO CustomProperties ([Public]) VALUES (#Public)";
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
OleDbCommand command = new OleDbCommand(query, connection);
command.Parameters.AddWithValue("#Public", "True");
connection.Open();
command.ExecuteNonQuery();
connection.Close();
}
return true;
}
public static string ReadDB()
{
string res = string.Empty;
string query = #"SELECT * FROM CustomProperties";
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
OleDbCommand command = new OleDbCommand(query, connection);
command.Parameters.AddWithValue("#Public", "True");
connection.Open();
res = (string)command.ExecuteScalar();
connection.Close();
}
return res;
}

The error was purely syntax, and I was guided by a really good example which I found in the following link
https://social.msdn.microsoft.com/Forums/en-US/24eac4c5-3a4d-43f4-8607-ef684919c4af/command-contains-unrecognized-phrasekeyword-vbnet?forum=visualfoxprogeneral
Working Code Blocks
public static bool CreateDBF()
{
try
{
string dbfDirectory = #"c:\Users\er4505\Desktop\New911";
string connectionString = "Provider=VFPOLEDB;Data Source=" + dbfDirectory;
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
connection.Open();
OleDbCommand command = connection.CreateCommand();
command.CommandText = "create table CustomProperties(Public C(60))";
command.ExecuteNonQuery();
connection.Close();
}
InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
return true;
}
catch (Exception ex)
{
string viewError = JsonConvert.SerializeObject(ex);
return false;
}
}
public static bool InsertDataIntoDBF(string path)
{
try
{
string strLogConnectionString = "Provider=VFPOLEDB;Data Source=" + path + ";Collating Sequence=machine;Mode=ReadWrite;";
string query = "INSERT INTO CustomProperties(Public) VALUES (?)";
using (OleDbConnection connection = new OleDbConnection(strLogConnectionString))
{
connection.Open();
OleDbCommand cmdInit = new OleDbCommand("set null off", connection);
cmdInit.ExecuteNonQuery();
OleDbCommand command = new OleDbCommand(query, connection);
OleDbParameter publicStatus = command.Parameters.Add("Public", OleDbType.Char);
publicStatus.Value = "True";
command.ExecuteNonQuery();
connection.Close();
}
return true;
}
catch (Exception ex)
{
log4net.LogManager.GetLogger("EmailLogger").Error(JsonConvert.SerializeObject(ex));
string viewError = JsonConvert.SerializeObject(ex);
return false;
}
}

public static bool CreateDBF()
{
...
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
...
}
InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF"); // change 1
return true;
}
catch (Exception)
{
throw; //change2
}
}
public static bool InsertDataIntoDBF(string path)
{
try
{
...
}
catch (Exception)
{
throw; //change 3
}
}

C# - Why is MySQL Server slow in my server machine?

I developed a POS like application and during testing with 2 PCs I didn't encounter any problems with the speed. It's just a simple LAN cable setup between 2 computers. But when I deployed it in a client, it ran slow.
The client has 1 PC serving as the admin and the main server, and there are 2 more PCs serving as the cashier. All connected in a router. The cashiers are connected to the admin's PC (main server) to retrieve, insert, update and delete data. I just want to ask if there are processes that needs to be done in MySQL or are there anything wrong with my codes when connecting to the database.
Here's my sample code for connecting to the database, I doubt having problems with it as this has been the standard in connecting to a database and adding records. Just in case I might bore you with codes, you can simply jump to the second code I posted, I have a comment there asking if the initialization of my class is correct. Thanks everyone!
class DBConnection
{
private MySqlConnection connection;
private MySqlCommand cmd;
private MySqlDataReader dr;
private DataTable tbl;
private MySqlDataAdapter da;
private DataSet ds;
private string connectionString;
private string server;
private string database;
private string uid;
private string password;
private frmNotifOk myNotification;
public DBConnection()
{
Initialize();
}
private void Initialize()
{
server = "CASHIER";
database = "sampledb";
uid = "root";
password = "samplepassword";
connectionString = "SERVER=" + server + ";" + "DATABASE=" + database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
connection = new MySqlConnection(connectionString);
}
private bool OpenConnection()
{
try
{
connection.Open();
return true;
}
catch (MySqlException ex)
{
switch (ex.Number)
{
case 0:
MessageBox.Show("Cannot connect to server.");
break;
}
return false;
}
}
private void CloseConnection()
{
try
{
connection.Close();
}
catch (MySqlException ex)
{
MessageBox.Show("Error: " + ex.Message);
}
}
public void AddRecord(String DBQuery, bool showNotif)
{
string query = DBQuery;
bool notify = showNotif;
try
{
if (this.OpenConnection() == true)
{
cmd = new MySqlCommand(query, connection);
cmd.ExecuteNonQuery();
if (notify)
{
MessageBox.Show("Item successfully added.");
}
}
}
catch (Exception ex)
{
MessageBox.Show("Error: " + ex.Message);
}
finally
{
this.CloseConnection();
}
}
And finally, here's how I use the method in a form:
public partial class frmNewCashier : Form
{
private DBConnection dbConnect;
string sampleDataSource= "SELECT * FROM SampleTable";
public frmNewCashier()
{
InitializeComponent();
//Is this the correct place of initializing my DBConnection class?
dbConnect = new DBConnection();
}
private void frmCashier_Load(object sender, EventArgs e)
{
try
{
dgvSearchItems.DataSource = dbConnect.DatabaseToDatagrid(dgvSearchItemsDataSource);
}
catch (Exception ex)
{
MessageBox.Show("Error: " + ex.Message);
}
}
}
I put the initialization of DBConnection class in public frmNewCashier(), is this the correct place or should I put it in Load event or somewhere? I'm thinking if this has bearing to the slowness of database. Aside from this question, do you know anything that I might have missed that causes the slowness?

class DBConnect
{
public MySqlConnection connection;
private string server;
private string database;
private string uid;
private string password;
//Constructor
public DBConnect()
{
Initialize();
}
//Initialize values
public void Initialize()
{
server = "localhost";
database = "db_sea_horses";
uid = "root";
password = " " ;
//password = "123";
string connectionString;
connectionString = "SERVER=" + server + ";" + "DATABASE=" + database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
connection = new MySqlConnection(connectionString);
}
//open connection to database
public bool OpenConnection()
{
try
{
connection.Open();
return true;
}
catch (MySqlException ex)
{ //0: Cannot connect to server.
//1045: Invalid user name and/or password.
switch (ex.Number)
{
case 0:
MessageBox.Show("Cannot connect to server. Contact administrator");
break;
case 1045:
MessageBox.Show("Invalid username/password, please try again");
break;
}
return false;
}
}
//Close connection
public bool CloseConnection()
{
try
{
connection.Close();
return true;
}
catch (MySqlException ex)
{
MessageBox.Show(ex.Message);
return false;
}
}
}
class DBmethods : DBConnect
{
DataSet dataset2;
public void input_sql(string query)
{
try
{
//open connection
if (this.OpenConnection() == true)
{
//create command and assign the query and connection from the constructor
MySqlCommand cmd = new MySqlCommand(query, connection);
//Execute command
int x = cmd.ExecuteNonQuery();
//close connection
this.CloseConnection();
}
}
catch(MySqlException myex)
{
MessageBox.Show(ex.Message);
}
}
///////////////////////////////////////////////
///// select
/////////////////////////////////////////////
public DataSet output_sql(string query,String table_name)
{
//Open connection
this.OpenConnection();
DataSet dataset = new DataSet();
MySqlDataAdapter adapter = new MySqlDataAdapter();
adapter.SelectCommand = new MySqlCommand(query, connection);
adapter.Fill(dataset, table_name);
//close Connection
this.CloseConnection();
//return list to be displayed
return dataset;
}
}
}
method calling example
1) insert / update / delete statement
DBmethods dbm = new DBmethods();
dbm.input_sql(" you can excute insert / update / delete query");
2) select statement
DataSet ds = dbm.output_sql("select * from storage_bunkers where job_id LIKE '%" + itemname.Text + "%' ", "storage_bunkers");
DataView myView = ((DataTable)ds.Tables["storage_bunkers"]).DefaultView;
dataGridView1.DataSource = myView;

First, try pinging from client machine to server which has installed SQL server. If it is taking too much time then there's problem with network connection.
If not, put a debug point and try debugging then identify the location that taking too long. Then you will able to get a answer.
Also, do not forget to close each and every db connection after using that.

C# SSH tunnel to MySQL server

I am trying to write a simple program to connect to a MySQL remote server that can only be connected to via SSH.
It reports the SSH connects and that the port forwards but then states that it cannot connect to any of the specified hosts?
Have I configured this wrong?
Below is the console output and the code:
using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Data;
using System.Web;
using System.Windows.Forms;
//Add MySql Library
using MySql.Data.Entity;
using MySql.Data.MySqlClient;
using MySql.Data.Types;
// SSH
using Renci.SshNet;
using Renci.SshNet.Common;
namespace MySQL_Console
{
class MainClass
{
public static void Main (string[] args)
{
PasswordConnectionInfo connectionInfo = new PasswordConnectionInfo ("mytestdb.co.uk", "root", "password123");
connectionInfo.Timeout = TimeSpan.FromSeconds (30);
using (var client = new SshClient(connectionInfo)) {
try
{
Console.WriteLine ("Trying SSH connection...");
client.Connect();
if (client.IsConnected)
{
Console.WriteLine ("SSH connection is active: {0}", client.ConnectionInfo.ToString());
}
else
{
Console.WriteLine ("SSH connection has failed: {0}", client.ConnectionInfo.ToString());
}
Console.WriteLine ("\r\nTrying port forwarding...");
var portFwld = new ForwardedPortLocal(Convert.ToUInt32(4479), "localhost", Convert.ToUInt32(3306));
client.AddForwardedPort(portFwld);
portFwld.Start();
if (portFwld.IsStarted)
{
Console.WriteLine ("Port forwarded: {0}", portFwld.ToString());
}
else
{
Console.WriteLine ("Port forwarding has failed.");
}
}
catch (SshException e)
{
Console.WriteLine ("SSH client connection error: {0}", e.Message);
}
catch (System.Net.Sockets.SocketException e)
{
Console.WriteLine ("Socket connection error: {0}", e.Message);
}
}
Console.WriteLine ("\r\nTrying database connection...");
DBConnect dbConnect = new DBConnect ("localhost", "test_database", "root", "passwrod123", "4479");
var ct = dbConnect.Count ("packages");
Console.WriteLine (ct.ToString());
}
}
// MySQL DB class
class DBConnect
{
private MySqlConnection connection;
private string server;
public string Server
{
get
{
return this.server;
}
set
{
this.server = value;
}
}
private string database;
public string Database
{
get
{
return this.database;
}
set
{
this.database = value;
}
}
private string uid;
public string Uid
{
get
{
return this.server;
}
set
{
this.server = value;
}
}
private string password;
public string Password
{
get
{
return this.password;
}
set
{
this.password = value;
}
}
private string port;
public string Port
{
get
{
return this.port;
}
set
{
this.port = value;
}
}
//Constructor
public DBConnect(string server, string database, string uid, string password, string port = "3306")
{
this.server = server;
this.database = database;
this.uid = uid;
this.password = password;
this.port = port;
Initialize();
}
//Initialize values
private void Initialize()
{
string connectionString;
connectionString = "SERVER=" + server + ";" + "DATABASE=" + database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
connection = new MySqlConnection(connectionString);
}
//open connection to database
private bool OpenConnection()
{
try
{
connection.Open();
Console.WriteLine("MySQL connected.");
return true;
}
catch (MySqlException ex)
{
//When handling errors, you can your application's response based on the error number.
//The two most common error numbers when connecting are as follows:
//0: Cannot connect to server.
//1045: Invalid user name and/or password.
switch (ex.Number)
{
case 0:
Console.WriteLine("Cannot connect to server. Contact administrator");
break;
case 1045:
Console.WriteLine("Invalid username/password, please try again");
break;
default:
Console.WriteLine("Unhandled exception: {0}.", ex.Message);
break;
}
return false;
}
}
//Close connection
private bool CloseConnection()
{
try
{
connection.Close();
return true;
}
catch (MySqlException ex)
{
Console.WriteLine(ex.Message);
return false;
}
}
//Insert statement
public void Insert()
{
string query = "INSERT INTO tableinfo (name, age) VALUES('John Smith', '33')";
//open connection
if (this.OpenConnection() == true)
{
//create command and assign the query and connection from the constructor
MySqlCommand cmd = new MySqlCommand(query, connection);
//Execute command
cmd.ExecuteNonQuery();
//close connection
this.CloseConnection();
}
}
//Update statement
public void Update(string tableName, List<KeyValuePair<string, string>> setArgs, List<KeyValuePair<string, string>> whereArgs)
{
string query = "UPDATE tableinfo SET name='Joe', age='22' WHERE name='John Smith'";
//Open connection
if (this.OpenConnection() == true)
{
//create mysql command
MySqlCommand cmd = new MySqlCommand();
//Assign the query using CommandText
cmd.CommandText = query;
//Assign the connection using Connection
cmd.Connection = connection;
//Execute query
cmd.ExecuteNonQuery();
//close connection
this.CloseConnection();
}
}
//Delete statement
public void Delete(string tableName, List<KeyValuePair<string, string>> whereArgs)
{
string query = "DELETE FROM tableinfo WHERE name='John Smith'";
if (this.OpenConnection() == true)
{
MySqlCommand cmd = new MySqlCommand(query, connection);
cmd.ExecuteNonQuery();
this.CloseConnection();
}
}
//Select statement
public List<string> Select(string queryString)
{
string query = queryString;
//Create a list to store the result
List<string> list = new List<string>();
//Open connection
if (this.OpenConnection() == true)
{
//Create Command
MySqlCommand cmd = new MySqlCommand(query, connection);
//Create a data reader and Execute the command
MySqlDataReader dataReader = cmd.ExecuteReader();
//Read the data and store them in the list
int fieldCOunt = dataReader.FieldCount;
while (dataReader.Read())
{
for (int i = 0; i < fieldCOunt; i++) {
list.Add(dataReader.GetValue(i).ToString());
}
}
//close Data Reader
dataReader.Close();
//close Connection
this.CloseConnection();
//return list to be displayed
return list;
}
return list;
}
//Count statement
public int Count(string tableName)
{
string query = "SELECT Count(*) FROM " + tableName;
int Count = -1;
//Open Connection
if (this.OpenConnection() == true)
{
//Create Mysql Command
MySqlCommand cmd = new MySqlCommand(query, connection);
//ExecuteScalar will return one value
Count = int.Parse(cmd.ExecuteScalar()+"");
//close Connection
this.CloseConnection();
return Count;
}
return Count;
}
//Backup
public void Backup()
{
try
{
DateTime Time = DateTime.Now;
int year = Time.Year;
int month = Time.Month;
int day = Time.Day;
int hour = Time.Hour;
int minute = Time.Minute;
int second = Time.Second;
int millisecond = Time.Millisecond;
//Save file to C:\ with the current date as a filename
string path;
path = "C:\\" + year + "-" + month + "-" + day + "-" + hour + "-" + minute + "-" + second + "-" + millisecond + ".sql";
StreamWriter file = new StreamWriter(path);
ProcessStartInfo psi = new ProcessStartInfo();
psi.FileName = "mysqldump";
psi.RedirectStandardInput = false;
psi.RedirectStandardOutput = true;
psi.Arguments = string.Format(#"-u{0} -p{1} -h{2} {3}", uid, password, server, database);
psi.UseShellExecute = false;
Process process = Process.Start(psi);
string output;
output = process.StandardOutput.ReadToEnd();
file.WriteLine(output);
process.WaitForExit();
file.Close();
process.Close();
}
catch (IOException e)
{
Console.WriteLine("Error {0}, unable to backup!", e.Message);
}
}
//Restore
public void Restore()
{
try
{
//Read file from C:\
string path;
path = "C:\\MySqlBackup.sql";
StreamReader file = new StreamReader(path);
string input = file.ReadToEnd();
file.Close();
ProcessStartInfo psi = new ProcessStartInfo();
psi.FileName = "mysql";
psi.RedirectStandardInput = true;
psi.RedirectStandardOutput = false;
psi.Arguments = string.Format(#"-u{0} -p{1} -h{2} {3}", uid, password, server, database);
psi.UseShellExecute = false;
Process process = Process.Start(psi);
process.StandardInput.WriteLine(input);
process.StandardInput.Close();
process.WaitForExit();
process.Close();
}
catch (IOException e)
{
Console.WriteLine("Error {0}, unable to Restore!", e.Message);
}
}
}
}

Try specifying 127.0.0.1 instead of localhost, or more generally IPAddress.Loopback.ToString(). Also, you don't need to explicitly cast to uint32. So you should try something like:
var portFwld = new ForwardedPortLocal(4479, IPAddress.Loopback.ToString(), 3306);
If that doesn't work, try also specifying the server name, something like:
var portFwld = new ForwardedPortLocal(IPAddress.Loopback.ToString(), 4479, "servername_goes_here", 3306);

Connection leak in database class

I have a simple C# MySQL connection class as:
using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Diagnostics;
using System.IO;
using MySql.Data.MySqlClient;
namespace FSB
{
public class DBConnect
{
private MySqlConnection connection;
private string server;
public string port;
private string database;
private string uid;
private string password;
//Constructor
public DBConnect()
{
Initialize();
}
~DBConnect()
{
//close connection
this.CloseConnection();
}
//Initialize values
private void Initialize()
{
// Local Database
server = "localhost";
database = "mydatabase";
uid = "user";
password = "pass";
string connectionString;
connectionString = "SERVER=" + server + ";Port=" + port + ";" + "DATABASE=" + database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
connection = new MySqlConnection(connectionString);
}
//open connection to database
private bool OpenConnection()
{
try
{
connection.Open();
return true;
}
catch (MySqlException ex)
{
//When handling errors, you can your application's response based on the error number.
//The two most common error numbers when connecting are as follows:
//0: Cannot connect to server.
//1045: Invalid user name and/or password.
switch (ex.Number)
{
case 0:
Console.WriteLine("Cannot connect to server. Contact administrator");
break;
case 1045:
Console.WriteLine("Invalid username/password, please try again");
break;
}
return false;
}
}
//Close connection
public bool CloseConnection()
{
try
{
if (connection.State == System.Data.ConnectionState.Open)
{
connection.Close();
connection.Dispose();
}
}
catch (MySqlException ex)
{
Console.WriteLine(ex.Message);
return false;
}
return true;
}
//Insert statement
public void Insert(String query)
{
//open connection
if (this.OpenConnection() == true)
{
//create command and assign the query and connection from the constructor
MySqlCommand cmd = new MySqlCommand(query, connection);
//Execute command
cmd.ExecuteNonQuery();
//close connection
this.CloseConnection();
}
}
//Update statement
public void Update(string query)
{
//Open connection
if (this.OpenConnection() == true)
{
//create mysql command
MySqlCommand cmd = new MySqlCommand();
//Assign the query using CommandText
cmd.CommandText = query;
//Assign the connection using Connection
cmd.Connection = connection;
//Execute query
cmd.ExecuteNonQuery();
//close connection
this.CloseConnection();
}
}
//Delete statement
public void Delete(string query)
{
if (this.OpenConnection() == true)
{
MySqlCommand cmd = new MySqlCommand(query, connection);
cmd.ExecuteNonQuery();
this.CloseConnection();
}
}
public MySqlDataReader getRecord(string query)
{
if (this.OpenConnection() == true)
{
//create mysql command
MySqlCommand cmd = new MySqlCommand();
MySqlDataReader reader;
//Assign the query using CommandText
cmd.CommandText = query;
//Assign the connection using Connection
cmd.Connection = connection;
//Execute query
reader = cmd.ExecuteReader();
return reader;
}
return null;
}
//Check Duplicate statement return true if not found
public bool checkDuplicate(string tableName ,String fieldName,String checkValue)
{
//Open connection
if (this.OpenConnection() == true)
{
//create mysql command
MySqlCommand cmd = new MySqlCommand();
MySqlDataReader reader;
int rowCount = 0;
//Assign the query using CommandText
String query = "Select * from `" + tableName + "` Where `"+fieldName + "` = '"+ checkValue +"'";
cmd.CommandText = query;
//Assign the connection using Connection
cmd.Connection = connection;
//Execute query
reader = cmd.ExecuteReader();
while (reader.Read())
{
//get rows
rowCount++;
}
//close connection
this.CloseConnection();
if (rowCount > 0)
{
return false;
}
}
return true;
}
}
}
Can anyone please where I am losing the connection as the connection remains open even after the object is out of scope every time the i use to do any operation a new connection is created and a previous connection is not closed. so I am running out of the connection limit to mysql ?

I suggest you to use using blok in order to clean your non managed object, your connection in this sample
using (var connection = new MySqlConnection("..."))
{
....
}
Nota : using blok execute dispose in the end of treatment in roder to clean
public void Insert(String query)
{
using(var connection = new MySqlConnection("..."))
{
connection.Open();
using(var cmd = new MySqlCommand(query, connection))
{
cmd.ExecuteNonQuery();
}
}
}

Verify if mysql command executed

I am using
public static bool command(string input, MySqlConnection con)
{
MySqlCommand command = new MySqlCommand(input, con);
var resultSet = command.ExecuteNonQuery();
if (!resultSet.Equals(0))
return true;
return false;
}
With as an example:
bool comm = mysql_command.command("INSERT INTO sometable (field1,field2) VALUES ('val1','val2')", connection);
if (!comm) textBox1.Text += "Command failed";
else textBox1.Text += "Command successful";
Which correctly adds Command successful to textbox1.
But when I change sometable to sometablee, textbox1 stays empty. I was expecting it to notify me the command failed (sometablee does not exist), but it didn't.
Can anyone tell me why?
Full code:
mysql_command:
class mysql_command
{
public static bool command(string input, MySqlConnection con)
{
MySqlCommand command = new MySqlCommand(input, con);
var resultSet = command.ExecuteNonQuery();
if (!resultSet.Equals(0))
return true;
return false;
}
}
mysql_connect:
class mysql_connect
{
private MySqlConnection connection = null;
public MySqlConnection connect(string server, string database, string UID, string password)
{
try
{
string MyConString = "SERVER=" + server + ";" +
"DATABASE=" + database + ";" +
"UID=" + UID + ";" +
"PASSWORD=" + password + ";";
connection = new MySqlConnection(MyConString);
connection.Open();
}
catch (Exception ex) { Console.WriteLine("MySQL connect error : "+ex.Message); }
return connection;
}
public void disconnect()
{
connection.Close();
}
}
Usage:
private void Form1_Load(object sender, EventArgs e)
{
mysql_connect con = new mysql_connect();
MySqlConnection connection = con.connect("server1.x.x", "somedb", "user", "pass");
bool comm = mysql_command.command("INSERT INTO sometable (field1,field2) VALUES ('val1','val1')", connection);
if (!comm) textBox1.Text += "Command failed";
else textBox1.Text += "Command successful";
}

The reason is as I expected, you will get an exception in your command method,
public static bool command(string input, MySqlConnection con)
because requested table is not exists, ....
Edit your command method to handle exception:
public static bool command(string input, MySqlConnection con)
{
try
{
MySqlCommand command = new MySqlCommand(input, con);
var resultSet = command.ExecuteNonQuery();
if (!resultSet.Equals(0))
return true;
return false;
}
catch
{}
return false;
}