Develop Reference

Sql insert c# windows forms

I am working on a windows form project with a sql database I want to write some data but I couldn't. (the code doesn't give any error however no data is written.
The code below is the place where I want to write the data:
public static string stringConnection = #"Data Source=(localdb)\MSSQLLocalDB; AttachDbFilename=|DataDirectory|\POS.mdf; Integrated Security=True";
try
{
mySql = string.Empty;
mySql += "INSERT INTO Journal (Date) VALUES (" + "'"+ caisse + "'"+")" ;
connection.exsql(mySql);
}
catch(Exception exx)
{
MessageBox.Show(exx.ToString());
}
and here is the connection.exsql method:
public static void exsql(string sql)
{
SqlConnection connection = new SqlConnection();
SqlDataAdapter adapter = default(SqlDataAdapter);
try
{
connection.ConnectionString = stringConnection;
connection.Open();
adapter = new SqlDataAdapter(sql, connection);
connection.Close();
//connection = null;
}
catch (Exception ex)
{
MessageBox.Show("Fatal sql error: " + ex.Message, "Sql Server connection failed", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}

You want to use the sqlCommand and execute .ExecuteNonQuery() to do an INSERT or UPDATE.
More info here.
Also, use parameterization (an example is shown in the link above), otherwise, you open yourself up to SQL injection and your code will fail if your variable contains a single quote.

Less code
private bool exsql(string query)
{
using(var conn = new SqlConnection(ConnectionString.path))
{
conn.Open();
using (var command = new SqlCommand(query, conn))
return command.ExecuteNonQuery() == 0 ? false : true;
}
}

SqlConnection con;
SqlCommand cmd;
public bool exsql(string query)
{
try {
con = null;
con = new SqlConnection(ConnectionString.path);
cmd = new SqlCommand(query, con);
con.Open();
var rowEffected = cmd.ExecuteNonQuery();
con.Close();
if(rowEffected>0)
{
return true;
}
else
{
return false;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Exception occurred !",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
}
}
You can execute your query by ExecuteNonQuery() function

Run SQL script from ASP.Net C# application performance issue

I'm running SQL script from C# code, my problem that the code take a long time to finish execution, it has many tables to be created in script(at least 30 Tables), so my code is working but it has performance issue.
this is the code
public static bool executeSqlScript(string scriptPath,string serverName,string databaseName)
{
try
{
SqlConnection myConn = new SqlConnection("Server=.;Integrated security=SSPI;database=master");
Server server = new Server(new ServerConnection(myConn));
string CreateCommand = "CREATE DATABASE " + databaseName + "";
string appendText;
//delete first line from script(Oldscript)
var lines = File.ReadAllLines(scriptPath).Skip(1);
File.WriteAllLines(scriptPath, lines);
using (StreamReader sreader = new StreamReader(scriptPath))
{
appendText = sreader.ReadToEnd();
}
File.Delete(scriptPath);
using (StreamWriter swriter = new StreamWriter(scriptPath, false))
{
appendText = "USE [" + databaseName + "]" + Environment.NewLine + appendText;
swriter.Write(appendText);
swriter.Close();
}
string readtext = File.ReadAllText(scriptPath);
SqlCommand myCommand = new SqlCommand(CreateCommand, myConn);
myConn.Open();
myCommand.ExecuteNonQuery();
server.ConnectionContext.ExecuteNonQuery(readtext);
return true;
}
catch (Exception e)
{
throw e;
return false;
}
}

My recommendation would be to migrate most of this to the SQL Server, once the new DB and User are setup, call a Stored Procedure to read the SQL file with the necessary DDL in it.
My last project was for a managed hosting company, and our CMS utilized well over 150 database objects. We used a "control" database which we pass in the new DB information and it would ceate the new tables, functions, and procedures generally in less than a minute.

use Parallel.ForEach to create tables likes
public static bool executeSqlScript(string scriptPath, string serverName, string databaseName)
{
try
{
SqlConnection myConn = new SqlConnection("Server=.;Integrated security=SSPI;database=master");
//Server server = new Server(new ServerConnection(myConn));
string CreateCommand = "CREATE DATABASE " + databaseName + "";
string appendText;
//delete first line from script(Oldscript)
//create db first
var myCommand = new SqlCommand(CreateCommand, myConn);
myConn.Open();
myCommand.ExecuteNonQuery();
myConn.Close();
List<string[]> list = File.ReadLines(scriptPath)
.Select(line => line.ToLower().Split(new string[] { "go" }, StringSplitOptions.None))
.ToList();
Parallel.ForEach(list, (sql) =>
{
using (var mysqlConn = new SqlConnection("Server=.;Integrated security=SSPI;database=master"))
{
var mysql = "USE [" + databaseName + "]" + Environment.NewLine + string.Join("", sql);
var mysqlCommand = new SqlCommand(mysql, mysqlConn);
myConn.Open();
mysqlCommand.ExecuteNonQuery();
}
});
//server.ConnectionContext.ExecuteNonQuery(readtext);
return true;
}
catch (Exception e)
{
throw e;
return false;
}
}

The problem was in Go Keyword in script, I Found this solution
http://www.codingdefined.com/2014/07/run-sql-script-file-in-c.html
(If you are trying to execute a SQL generated script file you have to remove all "GO". For that you have to use the following code...)
Here is my code:
string sqlConnectionString = "Data Source=.;Initial Catalog=master;Integrated Security=True";
FileInfo file = new FileInfo(#"D:\Script.sql");
string script = file.OpenText().ReadToEnd();
SqlConnection conn = new SqlConnection(sqlConnectionString);
conn.Open();
script = script.Replace("GO", "");
SqlCommand cmd = new SqlCommand(script, conn);
cmd.ExecuteNonQuery();
cmd.Dispose();
conn.Close();

C# SQL Server CE - Update won't work

I'm trying to finish a college project that requires a program to interact with a database.
Some of my naming is a little odd, but don't worry!
I'm trying to use a single submit button to either update or insert to the database.
Main issue is that I can't get an update to work though when I changed my code to try and fix it, I made it worse. Here is what I currently have.
private void btn_submit_Click(object sender, EventArgs e)
{
using (SqlCeConnection con = new SqlCeConnection(#"Data Source=G:\Dropbox\HND\Visual Studio\Visual C#\TestForms\TestForms\Database1.sdf"))
{
con.Open();
string taskSel = "SELECT TaskCode FROM TaskCode;";
SqlCeCommand c1 = new SqlCeCommand(taskSel, con);
SqlCeDataReader reader;
reader = c1.ExecuteReader();
if (reader.Read())
{
try
{
string taskUpdate = "UPDATE TaskCode SET TaskCode = #TaskCode, TaskDescription = #TaskDescription = WHERE TaskCode = #TaskCode;";
SqlCeCommand c = new SqlCeCommand(taskUpdate, con);
c.Parameters.AddWithValue("#TaskCode", cbx_taskCode.Text);
c.Parameters.AddWithValue("#TaskDescription", txt_desc.Text);
c.ExecuteNonQuery();
con.Close();
MessageBox.Show("Record has been updated");
MainMenu.Current.Show();
this.Close();
}
catch (SqlCeException exp)
{
MessageBox.Show(exp.ToString());
}
}
else
{
try
{
string taskInsert = "INSERT INTO TaskCode VALUES (#TaskCode, #TaskDescription);";
SqlCeCommand c = new SqlCeCommand(taskInsert, con);
c.Parameters.AddWithValue("#TaskCode", cbx_taskCode.Text);
c.Parameters.AddWithValue("#TaskDescription", txt_desc.Text);
c.ExecuteNonQuery();
con.Close();
MessageBox.Show("Record has been added");
MainMenu.Current.Show();
this.Close();
}
catch (SqlCeException exp)
{
MessageBox.Show(exp.ToString());
}
}
}
}
Has anyone got any ideas why I am getting an error on the c.ExecuteQuery line?
If I remove said line, it will not throw an exception, but it will not update the database.
Thanks

You have a simple syntax error in your update query just before the where statement.
There is an invalid equal sign
string taskUpdate = "UPDATE TaskCode SET TaskCode = #TaskCode, " +
"TaskDescription = #TaskDescription " +
"WHERE TaskCode = #TaskCode;";
Your query also could be simplified with
using (SqlCeConnection con = new SqlCeConnection(#"Data Source=G:\Dropbox\HND\Visual Studio\Visual C#\TestForms\TestForms\Database1.sdf"))
{
con.Open();
string taskSel = "SELECT COUNT(*) FROM TaskCode";
string cmdText;
SqlCeCommand c1 = new SqlCeCommand(taskSel, con);
int count = (int)c1.ExecuteScalar();
if (count > 0)
{
// Here there is no point to update the TaskCode. You already know the value
// Unless you have a different value, but then you need another parameter
// the 'old' TaskCode.....
cmdText = "UPDATE TaskCode SET " +
"TaskDescription = #TaskDescription " +
"WHERE TaskCode = #TaskCode;";
}
else
{
cmdText = "INSERT INTO TaskCode VALUES (#TaskCode, #TaskDescription);";
}
try
{
SqlCeCommand c = new SqlCeCommand(cmdText, con);
c.Parameters.AddWithValue("#TaskCode", cbx_taskCode.Text);
c.Parameters.AddWithValue("#TaskDescription", txt_desc.Text);
c.ExecuteNonQuery();
MessageBox.Show(count > 0 ? "Record has been updated" : "Record has been added");
MainMenu.Current.Show();
this.Close();
}
catch (SqlCeException exp)
{
MessageBox.Show(exp.ToString());
}
}

Not sure if it is the only problem, but you have an equal (=) sign before the WHERE keyword.

error for insert and stored data in access 2013

i have this code for insert data into access 2013
after click in the save button data insert into dataGridView and show
and when stop program and restart this,data not stored in the DB.I've done a lot of searches but can't find the solution. my class code and my button save code
class DB
{
public static OleDbConnection con = new OleDbConnection();
static DB()
{
con.ConnectionString = "Provider=MICROSOFT.ACE.OLEDB.12.0; " +
"Data Source=|DataDirectory|//Phonebook-db.accdb;Persist Security Info=True";
}
public static void Insert(Person p1)
{
try
{
OleDbCommand cmd = con.CreateCommand();
con.Open();
string s = "INSERT INTO Industrialist (S_Name,S_Family,S_Telephone,S_Major)VALUES('" + p1.Name + "','" + p1.Family + "','" + p1.Telephone + "','" + p1.Major + "')";
cmd.CommandType = CommandType.Text;
cmd.CommandText = s;
cmd.ExecuteNonQuery();
con.Close();
System.Windows.Forms.MessageBox.Show("Record successfully Added");
}
catch (OleDbException exp) { MessageBox.Show(exp.ToString()); }
}
}
Person p = new Person();
p.Name = txtname.Text;
p.Family = txtfamily.Text;
p.Telephone = txttell.Text;
p.Major = txtmajor.Text;
DB.Insert(p);
txttell.Text = "";
txtmajor.Text = "";
txtname.Text = "";
txtfamily.Text = "";
List<Person> people = DB.GetPeople();
dataGridView1.DataSource = people;

Choose your ACCDB file listed in your project files, select Copy To Output Directory and set its value to Never (And remember that |DataDirectory| is a substitution strings that points (for ASP.NET projects) to APP_DATA, your record is inserted in the database copied in that directory.
Said that please consider to use a parameterized query to create an sql command, not string concatenations
try
{
OleDbCommand cmd = con.CreateCommand();
con.Open();
string s = "INSERT INTO Industrialist (S_Name,S_Family,S_Telephone,S_Major)VALUES(" +
"?,?,?,?)";
cmd.CommandText = s;
cmd.Parameters.AddWithValue("#p1",p.Name);
cmd.Parameters.AddWithValue("#p2",p.Family);
cmd.Parameters.AddWithValue("#p3",p.Telephone);
cmd.Parameters.AddWithValue("#p4",p.Major);
cmd.ExecuteNonQuery();
con.Close();
System.Windows.Forms.MessageBox.Show("Record successfully Added");
}
catch (OleDbException exp) { MessageBox.Show(exp.ToString()); }
Of course do not close the connection before executing the command.
Another point to change is the usage pattern of your connection. Do not create a global connection and keep it around for the lifetime of your application. Simply create and use it when needed and close/dispose immediately after
using(OleDbConnection con = new OleDbConnection("Provider=MICROSOFT.ACE.OLEDB.12.0; " +
"Data Source=|DataDirectory|//Phonebook-db.accdb;" +
"Persist Security Info=True"))
{
try
{
OleDbCommand cmd = con.CreateCommand();
....
}
} // <- Here at the closing brace the connectio will be close and disposed

SQL delete command?

I am having trouble with a simple DELETE statement in SQL with unexpected results , it seems to add the word to the list??. Must be something silly!. but i cannot see it , tried it a few different ways. All the same result so quite confused.
public void IncludeWord(string word)
{
// Add selected word to exclude list
SqlConnection conn = new SqlConnection();
String ConnectionString = "Data Source = dev\\SQLEXPRESS ;" + "Initial Catalog=sml;" + "User id=** ;" + "Password =*;" + "Trusted_Connection=No";
using (SqlConnection sc = new SqlConnection(ConnectionString))
{
try
{
sc.Open();
SqlCommand Command = new SqlCommand(
"DELETE FROM excludes WHERE word='#word'" +
conn);
Command.Parameters.AddWithValue("#word", word);
Command.ExecuteNonQuery();
}
catch (Exception e)
{
Box.Text = "SQL error" + e;
}
finally
{
sc.Close();
}
ExcludeTxtbox.Text = "";
Box.Text = " Word : " + word + " has been removed from the Exclude List";
ExcludeLstBox.AppendDataBoundItems = false;
ExcludeLstBox.DataBind();
}

Try removing the single quotes. Also why are you concatenating your SQL string with a connection object (.. word='#word'" + conn)???
Try like this:
try
{
using (var sc = new SqlConnection(ConnectionString))
using (var cmd = sc.CreateCommand())
{
sc.Open();
cmd.CommandText = "DELETE FROM excludes WHERE word = #word";
cmd.Parameters.AddWithValue("#word", word);
cmd.ExecuteNonQuery();
}
}
catch (Exception e)
{
Box.Text = "SQL error" + e;
}
...
Notice also that because the connection is wrapped in a using block you don't need to Close it in a finally statement. The Dispose method will automatically call the .Close method which will return the connection to the ADO.NET connection pool so that it can be reused.
Another remark is that this IncludeWord method does far to many things. It sends SQL queries to delete records, it updates some textboxes on the GUI and it binds some lists => methods like this should be split in separate so that each method has its own specific responsibility. Otherwise this code is simply a nightmare in terms of maintenance. I would very strongly recommend you to write methods that do only a single specific task, otherwise the code quickly becomes a complete mess.

SqlCommand Command = new SqlCommand(
"DELETE FROM excludes WHERE word='#word'" +
conn);
should be replaced with
SqlCommand Command = new SqlCommand(
"DELETE FROM excludes WHERE word='#word'",
conn);
Also try by removing single quotes as suggested by others like this
SqlCommand Command = new SqlCommand(
"DELETE FROM excludes WHERE word=#word",
conn);

The #Word should not be in quotes in the sql query.
Not sure why you're trying to add the connection on the end of the sql query either.

To debug this, examine the CommandText on the SqlCommand object. Before reading further, you should try this.
The issue comes with adding the single quotes around a string that is parameterized. Remove the single quotes and life is beautiful. :-)
Oh, and your conn is an object and needs a comma, not a +.

See the code below:
private void button4_Click(object sender, EventArgs e)
{
String st = "DELETE FROM supplier WHERE supplier_id =" + textBox1.Text;
SqlCommand sqlcom = new SqlCommand(st, myConnection);
try
{
sqlcom.ExecuteNonQuery();
MessageBox.Show("delete successful");
}
catch (SqlException ex)
{
MessageBox.Show(ex.Message);
}
}
private void button6_Click(object sender, EventArgs e)
{
String st = "SELECT * FROM supplier";
SqlCommand sqlcom = new SqlCommand(st, myConnection);
try
{
sqlcom.ExecuteNonQuery();
SqlDataReader reader = sqlcom.ExecuteReader();
DataTable datatable = new DataTable();
datatable.Load(reader);
dataGridView1.DataSource = datatable;
}
catch (SqlException ex)
{
MessageBox.Show(ex.Message);
}
}

See the code below:
String queryForUpdateCustomer = "UPDATE customer SET cbalance=#txtcustomerblnc WHERE cname='" + searchLookUpEdit1.Text + "'";
try
{
using (SqlCommand command = new SqlCommand(queryForUpdateCustomer, con))
{
command.Parameters.AddWithValue("#txtcustomerblnc", txtcustomerblnc.Text);
con.Open();
int result = command.ExecuteNonQuery();
// Check Error
if (result < 0)
MessageBox.Show("Error");
MessageBox.Show("Record Update of Customer...!", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
con.Close();
loader();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
con.Close();
}

You can also try the following if you don't have access to some of the functionality prescribed above (due, I believe, to older versions of software):
using (var connection = _sqlDbContext.CreatSqlConnection())
{
using (var sqlCommand = _sqlDbContext.CreateSqlCommand())
{
sqlCommand.Connection = connection;
sqlCommand.CommandText = $"DELETE FROM excludes WHERE word = #word";
sqlCommand.Parameters.Add(
_sqlDbContext.CreateParameterWithValue(sqlCommand, "#word", word));
connection.Open();
sqlCommand.ExecuteNonQuery();
}
}
...
I'm an associate dev. Hence the "I believe" above.