C# Update in ado.net

C# Update in ado.net - c#

Old records are not deleting. Update acts like insert.
cn.Open();
string gen;
if (radioButton1.Checked == true)
gen = "Male";
else
gen = "Female";
string clas = null;
clas = comboBox1.Text;
string section = null;
section = comboBox2.Text;
SqlCommand cmd = new SqlCommand("update studetail set name='" + textBox2.Text + "','" + gen + "','" + textBox3.Text + "','" + clas + "','" + section + "' where studentno='" + textBox1.Text + "'");
cmd.Connection = cn;
int n = cmd.ExecuteNonQuery();

update acts like insert.
That's obvious cause you made it like so. Your below UPDATE statement is syntactically wrong
update studetail set name='" + textBox2.Text + "','" + gen + "','" + textBox3.Text + "','" + clas + "','" + section
It rather should be
update studetail set name='" + textBox2.Text + "',' gender = " + gen + "','" ...
Finally, you should consider using parameterized queries instead of concatanating user input likewise you are doing. It's prone to SQL Injection
SqlCommand cmd = new SqlCommand("update studetail set name= #name, gender = #gender, clas = #clas, section = #section where studentno = #studentno");
cmd.Parameters.Add(new SqlParameter("name", textBox2.Text));
cmd.Parameters.Add(new SqlParameter("gender", gen));
cmd.Parameters.Add(new SqlParameter("clas", clas));
cmd.Parameters.Add(new SqlParameter("section", section));
cmd.Parameters.Add(new SqlParameter("studentno", textBox1.Text));

Related

Couldn't save to MS Access database from C#

The values staring vith cmb is a combo box. When I click the save button, it throws an error.
My code is here:
cn.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = cn;
command.CommandText = "insert into TblProductDetails(ProductID, ProductName, Category, Section, UOM, CostPrice, SellingPrice1, SellingPrice2, DiscountPercentage, DiscountAmount, MinimumPrice, Vendor, Stock) values ('" + txtProductID.Text + "','" + txtName.Text + "','" + category + "','" + section + "','" + uom + "','" + txtCostprice.Text + "','" + txtSellingPrice1.Text + "','" + txtSellingPrice2.Text + "','" + txtDiscountpercentage.Text + "','" + txtDiscountAmount.Text + "','" + txtMinimumPrice.Text + "','" + vendor + "','" + txtBeginingStock.Text + "')";
command.ExecuteNonQuery();
cn.Close();

System.Data.OleDb.OleDbConnection conn = new
System.Data.OleDb.OleDbConnection();
conn.ConnectionString = #"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Your DataBasePath";
conn.Open();
System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand();
cmd.CommandType = System.Data.CommandType.Text;
cmd.CommandText = "INSERT INTO TblProductDetails (ProductID, ProductName, Category, Section, UOM, CostPrice, SellingPrice1, SellingPrice2, DiscountPercentage, DiscountAmount, MinimumPrice, Vendor, Stock) VALUES(#ProductID, #ProductName, #Category, #Section, #UOM, #CostPrice, #SellingPrice1, #SellingPrice2, #DiscountPercentage, #DiscountAmount, #MinimumPrice, #Vendor, #Stock)";
cmd.Parameters.AddWithValue("#ProductID", comboBox1.Text);
cmd.Parameters.AddWithValue("#ProductName", textBox1.Text);
cmd.Parameters.AddWithValue("#Category", textBox2.Text);
cmd.Parameters.AddWithValue("#Section", textBox2.Text);
cmd.Parameters.AddWithValue("#UOM", textBox4.Text);
// continue Your Code its just example
cmd.Connection = conn;
cmd.ExecuteNonQuery();
conn.Close();

It could be many things. See comment from Steve. But you also want to check the values in the text boxes for the " ' " character (apostrophe) as if the text box contains that character then that could also cause syntax issues, check out SQL injection for more information on that. Thought this was worth a mention. You could use a DataTableAdapter for this kind of thing too, or Entity Framework just to clear that up a little (I would do).

If combobox not selected any item enter empty string into Access database

When I enter a data in my Access database, if I do not select any item in the combobox, I get an error of null exception. So how can I make sure that if I did not select any items, empty data is inserted into my database?
OleDbConnection con = new OleDbConnection(#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Application.StartupPath + "\\db\\it.accdb");
if (comboBox10.SelectedItem == null)
{
comboBox10.Text = " ";
}
OleDbCommand cmd = new OleDbCommand();
cmd.CommandType = CommandType.Text;
cmd.CommandText = "insert into data ([Auto Date],AKA,[Phone Number],[R ID],[Related Phone],[Profession]) values ('" + textBox1.Text + "','" + textBox12.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox5.Text + "','" + comboBox10.SelectedItem.ToString() + "')";
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
System.Windows.Forms.MessageBox.Show("Data Inserted Successfully");
con.Close();

You can check if the SelectedItem property is null, then set a temp variable to use in your query string.
string comboBox10Text = comboBox10.SelectedItem == null ? String.Empty : comboBox10.Text;
Then use comboBox10Text in your query string.
Edit:
// Check if comboBox10.SelectedItem is null, set temp variable
string comboBox10Text = comboBox10.SelectedItem == null ? String.Empty : comboBox10.Text;
OleDbCommand cmd = new OleDbCommand();
cmd.CommandType = CommandType.Text;
// Update query string to use comboBox10Text instead of accessing SelectedItem
cmd.CommandText = "insert into data ([Auto Date],AKA,[Phone Number],[R ID],[Related Phone],[Profession]) values ('" + textBox1.Text + "','" + textBox12.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox5.Text + "','" + comboBox10Text + "')";
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
System.Windows.Forms.MessageBox.Show("Data Inserted Successfully");
con.Close();

You can have a null check and change the condition
If(comboBox10.SelectedItem != null)
{
cmd.CommandText = "insert into data ([Auto Date],AKA,[Phone Number],[R ID],[Related Phone],[Profession]) values ('" + textBox1.Text + "','" + textBox12.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox5.Text + "','" + comboBox10.SelectedItem.ToString() + "')";
}
else
{
cmd.CommandText = "insert into data ([Auto Date],AKA,[Phone Number],[R ID],[Related Phone],[Profession]) values ('" + textBox1.Text + "','" + textBox12.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox5.Text + "','" + "" + "')";
}

how do i get id of the last inserted row

i want to display booking id of the last inserted row.my insert code is given below. pls anyone can give me code to display the id
protected void Button1_Click(object sender, EventArgs e)
{
string cs = ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
SqlCommand cmd;
SqlDataReader dr;
con.Open();
cmd = new SqlCommand("insert into [booking] values('" + TextBox1.Text + "','" + TextBox2.Text + "','" + TextBox3.Text + "','" + TextBox4.Text + "','" + TextBox5.Text + "','" + TextBox6.Text + "','" + TextBox7.Text + "','" + TextBox8.Text + "','" + TextBox9.Text + "','" + TextBox10.Text + "','" + TextBox11.Text + "')", con);
cmd.ExecuteNonQuery();
}
}

I would suggest using something like this:
protected void Button1_Click(object sender, EventArgs e)
{
var cs = ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;
using (var con = new SqlConnection(cs))
{
con.Open();
var cmd = new SqlCommand(
"DECLARE #IDReturnTable TABLE( ID INT ); INSERT INTO [booking] OUTPUT INSERTED.NameOfYourIdColumn INTO #IDReturnTable VALUES(#param1, #param2, #param3); SELECT ID FROM #IDReturnTable",
con);
cmd.Parameters.Add("#param1", SqlDbType.VarChar).Value = TextBox1.Text;
cmd.Parameters.Add("#param2", SqlDbType.VarChar).Value = TextBox2.Text;
cmd.Parameters.Add("#param3", SqlDbType.VarChar).Value = TextBox3.Text;
var returnedId = cmd.ExecuteScalar();
}
}
I didn't use all 11 Text Boxes, just 3 to illustrate the technique.

You will be better off doing this as a stored procedure, and less susceptible to injection.
To achieve it with your current code, add a call to ;SELECT SCOPE_IDENTITY():
cmd = new SqlCommand("insert into [booking] values('" + TextBox1.Text + "','" + TextBox2.Text + "','" + TextBox3.Text + "','" + TextBox4.Text + "','" + TextBox5.Text + "','" + TextBox6.Text + "','" + TextBox7.Text + "','" + TextBox8.Text + "','" + TextBox9.Text + "','" + TextBox10.Text + "','" + TextBox11.Text + "');SELECT SCOPE_IDENTITY()", con);
And execute as scalar:
var id = cmd.ExecuteScalar();
(This assumes you have an identity column on your table)
To do it as a stored procedure:
If you have a finite number of values, you can just create the stored procedure normally, with an #Parameter for each TextBox.Text but with SELECT SCOPE_IDENTITY() at the end.
But it looks like you have a variable number of inputs, so see How to insert a multiple rows in SQL using stored procedures? which outlines an approach using a table paramater and one using a UDF to split a list of values.
Again, you would need to SELECT SCOPE_IDENTITY() at the end of the proc to pick up the identity of the last row.
For a detailed discussion on the ways of selecting the last inserted id see What is the difference between Scope_Identity(), Identity(), ##Identity, and Ident_Current?

C# SQL params Insert Query not Working Properly

Okay so I am trying to use parameters in C# sql code block but I am getting #Data in my SQL table please help
string connectionString = #"Network Library=DBMSSOCN;Data Source=**********,1433;database=*******;User id=*****;Password=******;";
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
//
// Description of SQL command:
// 1. It selects all cells from rows matching the name.
// 2. It uses LIKE operator because Name is a Text field.
// 3. #Name must be added as a new SqlParameter.
//
using (SqlCommand command = new SqlCommand(
"INSERT INTO [dbo].[event_logs] ([event_level],[date_and_time],[source],[event_id],[task_category],[event_data],[channel],[computer_id],[created_at],[updated_at])VALUES('" + entry.EntryType + "','" + entry.TimeWritten + "','" + entry.Source + "','" + entry.InstanceId + "','" + entry.Category + "',' #Data ','" + logtype + "','" + computerID + "','" + DateTime.Now.ToString() + "','" + DateTime.Now.ToString() + "')", connection))
{
//
// Add new SqlParameter to the command.
//
command.Parameters.Add(new SqlParameter("#Data", entry.Message));
//
// Read in the SELECT results.
//
SqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
}
}
}

INSERTs don't return results. Use .ExecuteNonQuery() instead of .ExecuteReader().

You are getting #Data because you SQL string is formatted like "',' #Data ','" which is wrong, it is no more a variable, it is itself a SQL String.
What you need to do is fix the SQL query from "',' #Data ','" to "', #Data ,'" it will be fine then.
using (SqlCommand command = new SqlCommand(
"INSERT INTO [dbo].[event_logs] ([event_level],[date_and_time],[source],[event_id],[task_category],[event_data],[channel],[computer_id],[created_at],[updated_at])VALUES('" + entry.EntryType + "','" + entry.TimeWritten + "','" + entry.Source + "','" + entry.InstanceId + "','" + entry.Category + "', #Data ,'" + logtype + "','" + computerID + "','" + DateTime.Now.ToString() + "','" + DateTime.Now.ToString() + "')", connection))
{
// Add new SqlParameter to the command.
command.Parameters.Add(new SqlParameter("#Data", entry.Message));
command.ExecuteNonQuery();
}

You need to specify the name and data type in the constructor, and the value in the new object:
command.Parameters.Add("#Data", SqlDbType.VarChar).Value = entry.Message;

private void button2_Click(object sender, EventArgs e)
{
try
{
string sSQL = "INSERT INTO StuTable (Name, Batch,CGPA, DOB, Program,
Picture)VALUES (#Name, #Batch,#CGPA,#DOB,#Program,#Picture)";
SqlCommand objCmd = new SqlCommand(sSQL, conn);
objCmd.Parameters.Add("#Name", SqlDbType.VarChar, 50);
objCmd.Parameters.Add("#Batch", SqlDbType.Int);
objCmd.Parameters.Add("#CGPA", SqlDbType.Float);
objCmd.Parameters.Add("#DOB", SqlDbType.VarChar, 50);
objCmd.Parameters.Add("#Program", SqlDbType.VarChar, 50);
objCmd.Parameters.Add("#Picture", SqlDbType.VarChar, 500);
//objCmd.Parameters["#RegdNo"].Value = Convert.ToInt32(textBox3.Text);
objCmd.Parameters["#Name"].Value = textBox4.Text;
objCmd.Parameters["#Batch"].Value = textBox5.Text;
objCmd.Parameters["#CGPA"].Value = textBox6.Text;
objCmd.Parameters["#DOB"].Value = maskedTextBox1.Text;
objCmd.Parameters["#Program"].Value = textBox8.Text;
objCmd.Parameters["#Picture"].Value = textBox9.Text;
objCmd.ExecuteNonQuery();
// MessageBox.Show("Record Added");
}
catch (Exception te)
{
MessageBox.Show(te.Message.ToString());
}
}

Insert record(s) DB from Form

I have an Access DB connected to my form with that code ( C# ) :
System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection();
conn.ConnectionString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data source= Z:\Tempesta\Area Progetto\Area_Progetto_20_02_2014\Area_Progetto_DATA_MAGAZINE\Data_Magazine\Data_Magazine\DB\DataMG.mdb";
try
{
System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand();
cmd.CommandType = System.Data.CommandType.Text;
cmd.CommandText = "INSERT into Prodotti ([Codice],[Descrizione],[Marchio],[Deposito],[Note],[NumeroProdotti],[PrzListinoBase_Aq],[PrzListinoBase_Ve],[Categoria],[Posizione],[Disponibilita],[QtaVenduta],[QtaAcquistata]) VALUES ('" + this.Codice.Text + "','" + this.Descr.Text + "','" + this.Marchio.Text + "','" + this.Deposito.Text + "'," + this.Note.Text + "," + this.NumProd.Text + "," + this.PrzListAcq.Text + "," + this.PrzListVen.Text + ",'" + this.Categ.Text + "','" + this.Posiz.Text + "'," + this.Disp.Text + "," + this.QtaVen.Text + "," + this.QtaAcq.Text + ")";
cmd.Connection = conn;
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
}
catch(Exception ex)
{
MessageBox.Show(ex.ToString());
// MessageBox.Show("Connessione Fallita!");
conn.Close();
}
finally
{
conn.Close();
}
The error I get when i click the buttton is this one :
Any ideas?

You are missing single quotations in Insert Statement where you are assigning values to columns. Your code is vulnerable so should avoid this here is a useful link.
Are Parameters really enough to prevent Sql injections?
System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection();
conn.ConnectionString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data source= Z:\Tempesta\Area Progetto\Area_Progetto_20_02_2014\Area_Progetto_DATA_MAGAZINE\Data_Magazine\Data_Magazine\DB \DataMG.mdb";
try
{
System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand();
cmd.CommandType = System.Data.CommandType.Text;
cmd.CommandText = "INSERT into Prodotti (Codice,Descrizione,Marchio,Deposito,Note,NumeroProdotti,PrzListinoBase_Aq,PrzListinoBase_Ve,Categoria,Posizione,Disponibilita,QtaVenduta,QtaAcquistata) VALUES('" + this.Codice.Text + "','" + this.Descr.Text + "','" + this.Marchio.Text + "','" + this.Deposito.Text + "','" + this.Note.Text + "','" + this.NumProd.Text + "','" + this.PrzListAcq.Text + "','" + this.PrzListVen.Text + "','" + this.Categ.Text + "','" + this.Posiz.Text + "','" + this.Disp.Text + "','" + this.QtaVen.Text + "','" + this.QtaAcq.Text + "')";
conn.Open();
cmd.Connection = conn;
cmd.ExecuteNonQuery();
conn.Close();
}
catch(Exception ex)
{
MessageBox.Show(ex.ToString());
// MessageBox.Show("Connessione Fallita!");
conn.Close();
}
finally
{
conn.Close();
}

I don't know italian (is that even the language? :) ) but from the look of it it could very well be a culture settings problem. If, for example, one of your fields is numeric then the database might expect a different decimal separator than the one in use in your UI.
Also your actual design seems very vulnerable to SQL Injection Attacks.
For these reasons, my suggestion is that you use the command's Parameters collection to set your values rather than trying to pass in a concatenated string.

I don't read the language you are posting the error from, however, it looks like a syntax error somewhere in your SqlCommand.
First thing I would suggest is wrapping your connection and command in using blocks to make sure they get disposed of correctly.
Then ALWAYS user parametarized SQL Commands to avoid SQL Injection:
using (var conn = new System.Data.OleDb.OleDbConnection(#"Provider=Microsoft.Jet.OLEDB.4.0;Data source= Z:\Tempesta\Area Progetto\Area_Progetto_20_02_2014\Area_Progetto_DATA_MAGAZINE\Data_Magazine\Data_Magazine\DB\DataMG.mdb"))
using (var cmd = new System.Data.OleDb.OleDbCommand())
{
cmd.CommandText = "INSERT INTO TableName (column1, column2, column3) VALUES (#Value1, #Value2, #Value3)";
cmd.Parameters.AddWithValue("#Value1", this.TextBox1.Text);
cmd.Parameters.AddWithValue("#Value2", this.TextBox2.Text);
cmd.Parameters.AddWithValue("#Value3", this.TextBox3.Text);
conn.Open();
cmd.ExecuteNonQuery();
}
Generally speaking, using parameters eliminates syntax errors because it makes the command much easier to read in it's string representation.

I think you may be missing single quotes around some of your text qualifiers in your INSERT statement.
"INSERT into Prodotti ([Codice],[Descrizione],[Marchio],[Deposito],[Note],[NumeroProdotti],[PrzListinoBase_Aq],[PrzListinoBase_Ve],[Categoria],[Posizione],[Disponibilita],[QtaVenduta],[QtaAcquistata]) VALUES ('" + this.Codice.Text + "','" + this.Descr.Text + "','" + this.Marchio.Text + "','" + this.Deposito.Text + "'," + this.Note.Text + "," + this.NumProd.Text + "," + this.PrzListAcq.Text + "," + this.PrzListVen.Text + ",'" + this.Categ.Text + "','" + this.Posiz.Text + "'," + this.Disp.Text + "," + this.QtaVen.Text + "," + this.QtaAcq.Text + ")";
Consider using a parameterized query rather than building your query string by hand. Not only is it safer, but it can help to weed out these kinds of errors which can be tedious to debug.
eg.
String StrSQL = "INSERT INTO tblLog ([Part_Number],[Quantity],[Date],[LOC_Warehouse],[LOC_Row],[LOC_Section],[LOC_Level],[LOC_Bin],[Stock_Added],[Stock_Removed],[Quarantine_Set],[Quarantine_Removed])"
+ "VALUES(#Part_Number, #Quantity, #Date, #Warehouse, #Row, #Section, #Level, #Bin, #Stock_Added, #Stock_Removed, #Quarantine_Set, #Quarantine_Removed)";
SqlConnection conn = new SqlConnection(WHITS.Properties.Settings.Default.LocalConnStr);
SqlCommand cmd = new SqlCommand(StrSQL, conn);
cmd.Parameters.AddWithValue("#Part_Number", Part_Number);
cmd.Parameters.AddWithValue("#Quantity", Quantity);
cmd.Parameters.AddWithValue("#Date", DateTime.Now);
//More Parameters... Skipped for brevity.
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();

Open your connection earlier. Also, use "using". Here's how I would do it:
try
{
string connectionString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data source= Z:\Tempesta\Area Progetto\Area_Progetto_20_02_2014\Area_Progetto_DATA_MAGAZINE\Data_Magazine\Data_Magazine\DB\DataMG.mdb";
using (System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(connectionString))
{
conn.Open();
string insertQuery = "INSERT into Prodotti ([Codice],[Descrizione],[Marchio],[Deposito],[Note],[NumeroProdotti],[PrzListinoBase_Aq],[PrzListinoBase_Ve],[Categoria],[Posizione],[Disponibilita],[QtaVenduta],[QtaAcquistata]) VALUES ('" + this.Codice.Text + "','" + this.Descr.Text + "','" + this.Marchio.Text + "','" + this.Deposito.Text + "'," + this.Note.Text + "," + this.NumProd.Text + "," + this.PrzListAcq.Text + "," + this.PrzListVen.Text + ",'" + this.Categ.Text + "','" + this.Posiz.Text + "'," + this.Disp.Text + "," + this.QtaVen.Text + "," + this.QtaAcq.Text + ")";
System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand(insertQuery, conn);
cmd.CommandType = System.Data.CommandType.Text;
cmd.ExecuteNonQuery();
conn.Close();
}
}
Edit: My bad... the code I was referencing was filling a DataAdapter, which doesn't require a call to connection.Open(). Regular querying does. My apologies... I have edited my suggestion.

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C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.

C# Update in ado.net - c#

Related

Couldn't save to MS Access database from C#

If combobox not selected any item enter empty string into Access database

how do i get id of the last inserted row

C# SQL params Insert Query not Working Properly

Insert record(s) DB from Form

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