I have problem with trying to figure out how to update and delete data inside a database using textboxes and a button.
My insert code is:
private void button4_Click(object sender, EventArgs e)
{
try
{
string query = "insert into Prodaja values (#Prodajalec,#Prodajalna,#Kupec,#Vozilo,#DatumNakupa)";
using (connection = new SqlConnection(connectionString))
using (SqlCommand command = new SqlCommand(query, connection))
{
connection.Open();
command.Parameters.AddWithValue("#Prodajalec", textBoxProdajalec.Text);
command.Parameters.AddWithValue("#Prodajalna", textBoxProdajalna.Text);
command.Parameters.AddWithValue("#Kupec", textBoxKupec.Text);
command.Parameters.AddWithValue("#Vozilo", textBoxVozilo.Text);
command.Parameters.AddWithValue("#DatumNakupa", textBoxDatumNakupa.Text);
command.ExecuteNonQuery();
}
MessageBox.Show("Uspešno dodano");
this.prodajaTableAdapter.Fill(this.prodajaDataSet.Prodaja);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
I tried a couple of different methods but they didnt really work out. Any help would be appreciated!
You seem to be mixing up the syntax of your insert vs update statement.
Insert statement:
insert into #table (col1,col2) values ('col1','col2')
Update statement
Update #table set col1 = 'col1', col2 = 'col2' where id = 'id'
EDIT: Delete Syntax
Delete from #table where id = 'id'
Related
I'm attempting to connect to a database and insert data into the pre-existing table. I'm able to connect to the database it seems but am having trouble getting the data to insert into the table. How do I insert
data into a database in visual studio?
I've already learned how to pass parameters and attempted that, but when I run the program I still receive exceptions. I've attached a screenshot of the error when I try and add a new record. I've looked up multiple different syntaxes for the insert statement, but not sure what I am doing wrong. Below I've included three screenshots one is the form itself, the error I receive, and at the bottom the table structure.
Insert Exception
Form
private void btnAccept_Click(object sender, EventArgs e)
{
if (IsValidData())
{
if (addProduct)
{
product = new Product();
this.PutProductData(product);
try
{
SqlConnection sqlConn = new SqlConnection("Data Source= (LocalDB)\\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\\MMABooks.mdf;Integrated Security=True");
SqlCommand sqlComm = new SqlCommand();
sqlComm = sqlConn.CreateCommand();
sqlComm.CommandText = #"INSERT INTO Products (paramColum) VALUES
(#ProductCode, #Description,
#UnitPrice, #OnHandQuantity)";
sqlComm.Parameters.Add("#ProductCode", SqlDbType.VarChar);
sqlComm.Parameters.Add("#Description", SqlDbType.VarChar);
sqlComm.Parameters.Add("#UnitPrice", SqlDbType.VarChar);
sqlComm.Parameters.Add("#OnHandQuantity", SqlDbType.VarChar);
sqlConn.Open();
sqlComm.ExecuteNonQuery();
sqlConn.Close();
// Add code here to call the AddProduct method of the ProductDB class.
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
}
}
}
private void btnAdd_Click(object sender, EventArgs e)
{
frmAddModifyProduct addProductForm = new
frmAddModifyProduct();
addProductForm.addProduct = true;
DialogResult result = addProductForm.ShowDialog();
if (result == DialogResult.OK)
{
product = addProductForm.product;
txtCode.Text = product.Code;
this.DisplayProduct();
}
}
It should enter a record into the Products table. If I get it down for the insert statement, I'll figure out the retrieve, update, and delete.
TableStructure
You need to add the parameter values, something like:
command.Parameters.Add("#LastName", SqlDbType.VarChar, 30).Value = "Smith";
command.Parameters.Add("#GenderCode", SqlDbType.Char, 1).Value = "M";.
Original answer below, but as pointed in comments below, please avoid it, reasons
cmd.Parameters.AddWithValue("#ProductCode", product.Code);
cmd.Parameters.AddWithValue("#Description", product.Description);
In the current code you have just setup the parameters but not passed the value.
EDIT: Based on #MaxSzczurek comments above
Your INSERT INTO columns don't match your VALUES clause.
INSERT INTO Products (paramColumn) should be changed to:
INSERT INTO Products(ProductCode, Description, UnitPrice, OnHandQuantity)
I have written this query in c# , query syntax is OK, query is also receiving parameter values as I have checked using breakpoints and also same query is working in SQL server management studio, but in visual studio it does not gives any error but also does not delete item from table.
private void deleteItem(int itemId, int saleId)
{
SqlConnection conn = new SqlConnection(connString);
SqlCommand deleteItem = new SqlCommand(
"Delete FROM items_in_sales WHERE sale_id=#sale_id AND item_id=#item_id",
conn);
deleteItem.Parameters.AddWithValue("#sale_id", itemId);
deleteItem.Parameters.AddWithValue("#item_id", saleId);
try
{
conn.Open();
deleteItem.ExecuteNonQuery();
conn.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
please help.
Fix your parameters they are wrong way around
deleteItem.Parameters.AddWithValue("#sale_id", itemId);
deleteItem.Parameters.AddWithValue("#item_id", saleId);
should be
deleteItem.Parameters.AddWithValue("#sale_id", saleId);
deleteItem.Parameters.AddWithValue("#item_id", itemId);
This is my code for insert into a table. It doesn't get any error, but it doesn't insert to the table. I tried by using stored_procedure too but it doesn't insert too. I can't find what I'm doing wrong.
private void btnSave_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = Properties.Settings.Default.bm_DatabaseConnectionString;
SqlCommand cmd = new SqlCommand();
cmd.Connection = con;
//cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "INSERT INTO [tbl_Buildings] (buildingName,buildingImage,buildingAddress,floorNo,apartsNo, buildingDesc) VALUES (#builName,#builImage,#builAddr,#floorNo,#apartsNo,#builDesc)";//"prc_AddNewBuilding";
cmd.Parameters.Add("#builName", txtBuildingName.Text);
cmd.Parameters.Add("#builAddr", txtAddress.Text);
cmd.Parameters.Add("#builImage", "Undefined");
cmd.Parameters.Add("#floorNo", (int)numFloorNo.Value);
cmd.Parameters.Add("#apartsNo", (int)numApartsNo.Value);
cmd.Parameters.Add("#builDesc", txtBuilDesc.Text);
try
{
con.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("New building has been added successfully");
this.Close();
}
catch (SqlException sqlex)
{
MessageBox.Show(sqlex.Message);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
con.Close();
}
}
I am using VS2012. What could I be doing wrong?
Try using:
Database.Command.Parameters.AddWithValue("#variableName", variable)
The only thing I could imagine why your values won't be inserted into your DB is a SQL Exception. Maybe you're missing some quotes?
Alternatiely use the complete "Add" Statement like this:
Database.Command.Parameters.Add(item, System.Data.SqlDbType.VarChar).Direction = ParameterDirection.Input
Item in this case is your variable containing the data you want to store
EDIT
My original answer assumed SQL Server was the database. As it turns out, the OP is using MS Access. Seems, based on other evidence, the file path for the .mdb file was the culprit, not the C# or SQL.
My original answer:
Using the connection string...
Server=myhost;Database=testdatatbase;Trusted_Connection=True;
the code you provided above works. I went to SQL Enterprise Manager, created a table named dbo.tbl_Buildings with the following attributes...
buildingName = nvarchar(50)
buildingImage = nvarchar(50)
buildingAddress = nvarchar(50)
floorNo = int
apartsNo = int
buildingDesc = nvarchar(50)
I then passed in dummy values, then ran the following query...
select * from testdatatbase.dbo.tbl_Buildings
and it shows the record....
-- seems to work for me...
(Maybe check your datatypes - make sure your table types match your types in the code)
in my project I have set the client name as primary key and if I enter the same value, I will get exception, now I want to write the validation, i.e if I re enter the primary key value then I should get a message like "Data already exists", Please help me to do that, The code I am using to insert value is:
private void btnInsert_Click(object sender, EventArgs e)
{
if (txtName.Text == string.Empty)
{
MessageBox.Show("Please enter a value to Project Name!");
txtName.Focus();
return;
}
if (txtContactPerson.Text == string.Empty)
{
MessageBox.Show("Please enter a value to Description!");
txtContactPerson.Focus();
return;
}
SqlConnection con = Helper.getconnection();
con.Open();
string commandText = "InsertClient";
SqlCommand cmd = new SqlCommand(commandText, con);
cmd.Parameters.AddWithValue("#Name", txtName.Text);
cmd.Parameters.AddWithValue("#ContactPerson", txtContactPerson.Text);
cmd.CommandType = CommandType.StoredProcedure;
MessageBox.Show("Client details are inserted successfully");
txtName.Clear();
txtContactPerson.Clear();
object Name = cmd.ExecuteNonQuery();
con.Close();
BindData();
}
First, you can prevent a duplicate from ever occurring in the table by using a unique index or constraint. An index/constraint can work in concert with the suggestions below. If you only use a unique index and not one of the below solutions, inserting a duplicate record will throw an error and you will need to handle that on the other end.
you could check for the records existence and insert or update manually:
create procedure MyProcedure
(
#Name nvarchar(100),
...
)
as
if not exists (select * from MyTable where Name = #Name)
begin
insert into MyTable (Name,...) values (#Name,...)
end
else
begin
update MyTable
set ...
where Name = #Name
end
I would tend to allow the user to try to enter any superficially valid primary key, If it is a duplicate then there will be an exception that you can catch and display to the user.
The reason for this is you would have to check the database for an existing key so you might as well do this by trying to insert it and handling any errors.
You could probably improve the validation and error handling a lot more, popping up a message box on every individual problem is annoying, better to have a summary with all the problems. Also holding open a database connection while displaying a message box probably isn't advisable either.
private void btnInsert_Click(object sender, EventArgs e)
{
if (txtName.Text == string.Empty)
{
MessageBox.Show("Please enter a value to Project Name!");
txtName.Focus();
return;
}
if (txtContactPerson.Text == string.Empty)
{
MessageBox.Show("Please enter a value to Description!");
txtContactPerson.Focus();
return;
}
SqlConnection con = Helper.getconnection();
con.Open();
string commandText = "InsertClient";
SqlCommand cmd = new SqlCommand(commandText, con);
cmd.Parameters.AddWithValue("#Name", txtName.Text);
cmd.Parameters.AddWithValue("#ContactPerson", txtContactPerson.Text);
cmd.CommandType = CommandType.StoredProcedure;
try
{
object Name = cmd.ExecuteNonQuery();
MessageBox.Show("Client details are inserted successfully");
txtName.Clear();
txtContactPerson.Clear();
BindData();
}
catch(Exception ex)
{
//Handle exception, Inform User
}
finally
{
con.Close();
}
}
I understand your requirement, I see that you are asking about using of your own code instead of the exception. You can get it by using the try catch block. Try the following code:
try
{
object Name = cmd.ExecuteNonQuery();
MessageBox.Show("Client details are inserted successfully");
txtName.Clear();
txtContactPerson.Clear();
BindData();
}
catch(Exception ex)
{
//Handle exception, Inform User
}
finally
{
con.Close();
}
I tend to use Entity Framework as it will throw an exception in this case, however I suppose you could run an sql query first to check whether it exists or not, or though there may be a significant performance overhead with that
I have read TONS of tutorials, articles and whatever regarding my issue and honestly, due to my lack of experience I can't twist my fingers around this one so I hope some of you guys can help me out :)
I am working on a project (simply to learn how to program so it's probably very basic), but I have this "News" page where I can update and delete data using a GridView.
Now I would like to INSERT something into my database using 3 textboxes and 1 submit button.
I have 3 rows that has to be inserted:
Headline
Date
Content/the news itself.
Which are stored under NyhedTB from the connectionstring: BoligStjernenConnectionString
My query looks like this:
INSERT INTO [NyhedTB] ([NyhedDato], [NyhedTitel], [NyhedTekst])
VALUES (#NyhedDato, #NyhedTitel, #NyhedTekst)
I read on the internet that this code should do the magic for me (I will have to insert my own values ofc.):
static void Insert()
{
try
{
string connectionString =
"server=.;" +
"initial catalog=employee;" +
"user id=sa;" +
"password=sa123";
using (SqlConnection conn =
new SqlConnection(connectionString))
{
conn.Open();
using (SqlCommand cmd =
new SqlCommand("INSERT INTO EmployeeDetails VALUES(" +
"#Id, #Name, #Address)", conn))
{
cmd.Parameters.AddWithValue("#Id", 1);
cmd.Parameters.AddWithValue("#Name", "Amal Hashim");
cmd.Parameters.AddWithValue("#Address", "Bangalore");
int rows = cmd.ExecuteNonQuery();
//rows number of record got inserted
}
}
}
catch (SqlException ex)
{
//Log exception
//Display Error message
}
}
I looked at this code and thought it should be easy enough but really, I can't figure it out.
Here is some advice to get you going, learning programming is a lot of
trial and error.
Start off basic, litrally put three textboxes on a form/page and a
button.
Double click the button to go the code-behind and view the buttons
click event.
Paste in the body of code included with your question (everything in the try-catch).
Put a break-point on the Public Void Button_Click line of code and press F11 to
step through the code.
"one thing is having the code-behind working but how to make the buttons and textboxes working is still a misery"*
Put the textbox as the value rather than your hardcoded values:
cmd.Parameters.AddWithValue("#Address", textBox1.Text);
You also should not insert the Id value, instead modify the EmployeeDetails table and set the ID column to in the properties set Identity Specification (IS Identity) = True. Then right click the ID column and set Primary Key.
Post any error messages you encounter here and when you do get get it working, an additional exercise (that will be very valuable for you) would use a database stored procedure rather than ad-hoc SQL, to safe-guard against sql-injection attacks.
I'm assuming you have SQL Server installed and have a 'employee' database with a table called EmployeeDetails.
protected void GvManualShows_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
//label lbl = (label)e.Row.FindControl("lblHidden");
if (e.Row.Cells[14].Text == "Y")
{
// CheckBox cb = (CheckBox)e.Row.FindControl("chk");
CheckBox chk = (CheckBox)e.Row.Cells[0].FindControl("chkBox");
chk.Checked = true;
}
}
}
It's fairly simple. You just have to modify the connection string, the query and its parameters:
private void button1_Click(object sender, EventArgs e)
{
try
{
string connectionString =
"server=SQLServer;" + // SQLServer is your SQL server machine
"initial catalog=employee;" + // employee is your database
"user id=sa;" + // sa is the login to connect the database
"password=sa123"; // sa123 is the password of the login
using (SqlConnection conn =
new SqlConnection(connectionString))
{
conn.Open();
using (SqlCommand cmd = new SqlCommand(
"INSERT INTO [NyhedTB] ([NyhedDato], [NyhedTitel], [NyhedTekst]) " +
"VALUES (#NyhedDato, #NyhedTitel, #NyhedTekst)", conn))
{
cmd.Parameters.AddWithValue("#NyhedDato", textBoxDate.Text);
cmd.Parameters.AddWithValue("#NyhedTitel", textBoxTitle.Text);
cmd.Parameters.AddWithValue("#NyhedTekst", textBoxBody.Text);
int rows = cmd.ExecuteNonQuery(); // Inserted rows number
}
}
}
catch (SqlException ex)
{
//Log exception
//Display Error message
}
}
I made changed example code with your requirements and added comments, hope it would be a bit clearer for you to understand whats going on:
static void Insert()
{
try
{
string connectionString =
"server=.;" +
"initial catalog=MyDatabaseName;" + //here you write database name where your NyhedTB table is
"user id=sa;" + //user name to connect to database
"password=sa123"; //password
using (SqlConnection conn = new SqlConnection(connectionString))
{
conn.Open();
using (SqlCommand cmd =
new SqlCommand("INSERT INTO NyhedTB (NyhedDato, NyhedTitel, NyhedTekst) VALUES (#NyhedDato, #NyhedTitel, #NyhedTekst)", conn))
{
//all "things" in your sql command what beggins with #
//means that it is parameter and you need to pass values for these parameters:
//For #NyhedDato parameter you set text from your textbox
cmd.Parameters.AddWithValue("#NyhedDato", txtDate.Text);
//For #NyhedTitel parameter you set text from title textbox
cmd.Parameters.AddWithValue("#NyhedTitel", txtTitle.Text);
//For #NyhedTekst parameter you set text from content textbox
cmd.Parameters.AddWithValue("#NyhedTekst", txtContent.Text);
//Execute insert command and get how many records was efected, in this case it should be rows = 1 because you inserting just one record
int rows = cmd.ExecuteNonQuery();
}
}
}
catch (SqlException ex)
{
//Log exception
//Display Error message
}
}
P.s. code not tested. And when you say
I have 3 rows that has to be inserted:
Headline
Date
Content/the news itself.
actually you mean you want to insert record with fields