Checking database data from textbox - c#

I have a textbox which will take the input from user and search whether the inserted data is available in SQL database table or not. If the data is in table then it will update two column(time_out and day_out) of the same row.
Or else it will show an error message. This code below is not working. Please help.
try
{
SqlConnection con3 = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=db-ub;Integrated Security=True");
con3.Open();
SqlCommand cmd2 = new SqlCommand(#"SELECT Count(*) FROM Visitors WHERE Id=#id",con3);
cmd2.Parameters.AddWithValue("#id", textBox_VIex.Text);
SqlCommand cmd3 = new SqlCommand("UPDATE Visitors SET Day_Out=#dO,Time_Out=#tO WHERE Id=#id", con3);
cmd3.Parameters.AddWithValue("#id", 1);
cmd3.Parameters.AddWithValue("#dO", DateTime.Now);
cmd3.Parameters.AddWithValue("#tO", DateTime.Now);
int o = cmd3.ExecuteNonQuery();
MessageBox.Show("Good Bye!");
this.Close();
FormCheck f2 = new FormCheck();
f2.Show();
}
catch
{
MessageBox.Show("Error!");
textBox_VIex.Clear();
}

Please refer to my changes to your code,
int o = cmd3.ExecuteNonQuery();
Returns the count of number of rows affected by the Query. If it is zero it means that id was not in the database.
try
{
SqlConnection con3 = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=db-ub;Integrated Security=True");
con3.Open();
SqlCommand cmd2 = new SqlCommand(#"SELECT Count(*) FROM Visitors WHERE Id=#id",con3);
cmd2.Parameters.AddWithValue("#id", textBox_VIex.Text);
SqlCommand cmd3 = new SqlCommand("UPDATE Visitors SET Day_Out=#dO,Time_Out=#tO WHERE Id=#id", con3);
cmd3.Parameters.AddWithValue("#id", int.Parse(textBox_VIex.Text));
cmd3.Parameters.AddWithValue("#dO", DateTime.Now);
cmd3.Parameters.AddWithValue("#tO", DateTime.Now);
int o = cmd3.ExecuteNonQuery();
if(o > 0)
MessageBox.Show("Good Bye!");
else
MessageBox.Show("Error!");
this.Close();
FormCheck f2 = new FormCheck();
f2.Show();
}
catch
{
MessageBox.Show("Error!");
textBox_VIex.Clear();
}

Look into comments in code.
First, this is good way to deal with connection, etc
int? result = null; // note nullable int
try
{
Using (SqlConnection con = New SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=db-ub;Integrated Security=True"))
{
con.Open();
// You don't really care to check up front if the record with id=xx exists because
// if it doesn't, you get 0 records updated
// unless you do something with the result of that query
Using (SqlCommandcmd As New SqlCommand("UPDATE Visitors SET Day_Out=#dO,Time_Out=#tO WHERE Id=#id", con))
{
cmd.CommandType = CommandType.Text;
cmd.Parameters.AddWithValue("#id", 1); // <<-- Are you always passing "1"?????
cmd.Parameters.AddWithValue("#dO", DateTime.Now);
cmd.Parameters.AddWithValue("#tO", DateTime.Now);
result = cmd.ExecuteNonQuery();
}
con.Close()
}
}
catch
{
// optionally, log error or show error msg in second msgBox below. Save it to a variable here
}
// Separate query and result processing
// Check the result. If result is still null, your query failed. If not 0 - you updated your records
if (result != null && (int)result > 0)
{
MessageBox.Show("Updated record OK");
}
else
{
if (result == null)
{
MessageBox.Show("The construct failed"); // optionally add error msg here
}
else
{
MessageBox.Show("The record I was looking for is not in DB");
}
}
// I don't know what you do with your form logic
this.Close();

Related

Insert data from radio button into database

Building a form application in C# for selling phones as a project. I have two radio buttons which the user checks based on what type of payment method they want cash or card.
How do I insert that data into the database based on what the user selects?
You can try this,
protected void Button1_Click(object sender, EventArgs e)
{
string cs = ConfigurationManager.ConnectionStrings["db"].ConnectionString;
SqlConnection cn = new SqlConnection(cs);
SqlCommand cmd = new SqlCommand();
cmd.Connection = cn;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "insert into sample values(#payment)";
cmd.Parameters.Clear();
cmd.Parameters.AddWithValue("#payment", payment.SelectedValue);
if (cn.State == ConnectionState.Closed)
cn.Open();
cmd.ExecuteNonQuery();
cn.Close();
lblmsg.Text = "Data entered successfully!!!";
}
I found the answer to my own question if someone needs it
try
{
var connection = getConnection();
connection.Open();
if (CashRadio.Checked == true)
{
var command = new SqlCommand
{
Connection = connection,
CommandText ="INSERT INTO type_payment(cash,card) values(1,0)"
};
command.Parameters.Clear();
int result = command.ExecuteNonQuery();
if (result > 0)
{
MessageBox.Show("Succsefully picked type");
}
else
{
MessageBox.Show("error");
}
}
else if (CardRadio.Checked == true)
{
var command = new SqlCommand
{
Connection = connection,
CommandText = "INSERT INTO type_payment(cash,card) values(0,1)"
};
command.Parameters.Clear();
int result = command.ExecuteNonQuery();
if (result > 0)
{
MessageBox.Show("Succesfully picked type");
}
else
{
MessageBox.Show("Error");
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
Luka,
Try it below.
Add HTML Markup like:
<asp:CheckBox ID="chkCash" runat="server" />
.cs file add below code.
string Cash = chkCash.Checked ? "Y" : "N";
And send or add value like.
SqlCommand cmd = new SqlCommand("INSERT INTO Employees(Cash) VALUES(#Cash)"))
{
cmd.Parameters.AddWithValue("#Cash", Cash);
}

Value from DropDownList will not save into SQL Server table

I have a DropDownList that gets populated by a SQL Server table called tblVisa. My issue is that the values that are being populated from the SQL Server table are not being saved. Everything else gets saved except for my DropDownLists. I've tried using .SelectedValue and .Text, but it still does not work.
Here is my code
protected void PopulateVisaType()
{
List<ListItem> result = new List<ListItem> { new ListItem("", "") };
SqlCommand cmd = new SqlCommand() { Connection = sqlConn, CommandText = "SELECT VisaType FROM tblVisa ORDER BY VisaType ASC" };
if (sqlConn.State == ConnectionState.Closed)
{
sqlConn.Open();
}
SqlDataReader read = cmd.ExecuteReader();
while (read.Read())
{
result.Add(new ListItem(read["VisaType"].ToString(), read["VisaType"].ToString()));
}
read.Close();
sqlConn.Close();
cmd.Dispose();
DDLVisa.DataSource = result;
DDLVisa.DataValueField = "value";
DDLVisa.DataTextField = "text";
DDLVisa.DataBind();
}
Here's my code for saving the information into the database:
protected void LbSaveProfile_Click(object sender, EventArgs e)
{
SqlCommand cmd = new SqlCommand() { Connection = sqlConn, CommandText = "spSaveNewProviderInformation", CommandType = CommandType.StoredProcedure };
if (sqlConn.State == ConnectionState.Closed)
{
sqlConn.Open();
}
cmd.Parameters.AddWithValue("#EmployeeNumber", TbEmployeeNumber.Text.Trim());
cmd.Parameters.AddWithValue("#SSN", TbSSN.Text.Trim());
cmd.Parameters.AddWithValue("#ContractType", DDLContractType.SelectedItem.Value);
cmd.Parameters.AddWithValue("#Firstname", TbFirstname.Text.Trim());
cmd.Parameters.AddWithValue("#Lastname", TbLastname.Text.Trim());
cmd.Parameters.AddWithValue("#MiddleInitial", TbMiddleInitial.Text.Trim());
cmd.Parameters.AddWithValue("#ContractRenewalDate", TbContractRenewalDate.Text.Trim());
cmd.Parameters.AddWithValue("#Position", DDLPosition.Text.Trim());
cmd.Parameters.AddWithValue("#Specialty", DDLSpecialty.Text.Trim());
cmd.Parameters.AddWithValue("#PrimaryDepartment", DDLPrimaryDepartment.Text.Trim());
cmd.Parameters.AddWithValue("#SecondaryDepartment", DDLSecondaryDepartment.Text.Trim());
cmd.Parameters.AddWithValue("#Gender", DDLGender.Text.Trim());
cmd.Parameters.AddWithValue("#Birthdate", TbBirthdate.Text.Trim());
cmd.Parameters.AddWithValue("#EmailAddress", TbEmailAddress.Text.Trim());
cmd.Parameters.AddWithValue("#PhoneNumber", TbPhoneNumber.Text.Trim());
cmd.Parameters.AddWithValue("#Address", TbAddress.Text.Trim());
cmd.Parameters.AddWithValue("#PassportNumber", TbPassportNumber.Text.Trim());
cmd.Parameters.AddWithValue("#Citizenship", DDLCitizenship.Text.Trim());
cmd.Parameters.AddWithValue("#Visa", DDLVisa.Text.Trim());
cmd.Parameters.AddWithValue("#Status", 1);
cmd.ExecuteNonQuery();
sqlConn.Close();
Alert("Provider Information saved!");
ClearControls();
}
You much better to provide the drop down list with column names.
So, say this:
protected void PopulateVisaType()
{
SqlConnection sqlConn = new SqlConnection("");
using (SqlCommand cmd = new SqlCommand("SELECT VisaType FROM tblVisa ORDER BY VisaType ASC", sqlConn))
{
if (sqlConn.State == ConnectionState.Closed)
{
sqlConn.Open();
}
DDLVisa.DataSource = cmd.ExecuteReader();
DDLVisa.DataValueField = "VisaType";
DDLVisa.DataTextField = "VisaType";
DDLVisa.DataBind();
//DDLVisa.Items.Insert(0, new ListItem("")); // optional blank row choice
sqlConn.Close();
}
}
So the TextField, and the DataText field need to be a named column from the data source.
I also included an optional first blank option if you need/want/expect to have no choice.
However, keep in mind that this empty string should be translated into a null in your database if you don't allow (or want) empty strings, and want a null for that value. This applies to all of your values. (perhaps the stored procedure does this?).

ExecuteNonQuery() returns -1

For some reason result is always -1 and nothing get added to the database. I executed the query in SQL Server and it runs fine. I don't get any exception whatsoever and I don't use any stored procedure.
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=RAINBOW;Integrated Security=True");
SqlCommand cmd;
cmd = new SqlCommand("INSERT INTO ItemDetails.item(description,category_id) VALUES (#item_desc,#cat_id)", con);
cmd.Parameters.AddWithValue("#item_desc", txtitemdesc.Text);
cmd.Parameters.AddWithValue("#cat_id", GetCategoryID());
try
{
con.Open();
int result = cmd.ExecuteNonQuery();
if (result > 0)
{
MessageBox.Show("Record Inserted Successfully!");
}
else
{
MessageBox.Show("Failed to add record");
}
}
catch (SqlException ex)
{
MessageBox.Show("An error has occured! " + ex);
}
finally
{
con.Close();
}
Edit
int GetCategoryID()
{
int cat_id = 0;
cmd = new SqlCommand("SELECT category_id FROM ItemDetails.category WHERE category_desc=#cat_desc", con);
con.Open();
cmd.Parameters.AddWithValue("#cat_desc", cboCategory.Text);
reader = cmd.ExecuteReader();
while (reader.Read())
{
cat_id = int.Parse(reader["category_id"].ToString());
}
reader.Close();
con.Close();
return cat_id;
}
If possible then don't use AddWithValue(). Actually when you are not providing type explicitly, it will try to convert implicitly and sometimes the implicit conversion may not be the most optimal of conversions. You can find some more discussion in this link.
And most important thing is don't forget to clear parameters before assign, by using this line.
cmd.Parameters.Clears();
Check below code.
string sqlQuery = "INSERT INTO ItemDetails.item(description,category_id) VALUES (#item_desc,#cat_id)";
using (SqlCommand cmd = new SqlCommand(sqlQuery, con))
{
cmd.CommandType = CommandType.Text;
cmd.Parameters.Clears(); // Add this same line in your getcategory function.
cmd.Parameters.Add("#item_desc", SqlDbType.VarChar, 1000).Value = txtitemdesc.Text;
cmd.Parameters.Add("#cat_id", SqlDbType.Int).Value = GetCategoryID();
try
{
con.Open();
int result = cmd.ExecuteNonQuery();
if (result > 0)
{
MessageBox.Show("Record Inserted Successfully!");
}
else
{
MessageBox.Show("Failed to add record");
}
}
catch (SqlException ex)
{
MessageBox.Show("An error has occured! " + ex);
}
finally
{
con.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.

c# Database saving problem from a ListView

I have a ListView. It has 6 columns:
question_id | question_text | start_time | end_time | status | repeat
respectively. Right now I am able to display the data from the database. This is my code:
private void Voting_Editor_Tool_Load(object sender, EventArgs e)
{
GetData();
}
public void GetData()
{
try
{
now = DateTime.Now;
String time_date = now.ToString();
myConnection = new SqlConnection(#"User ID=sa;Password=password123;Initial Catalog=dishtv;Persist Security Info=True;Data Source=ENMEDIA-EA6278E\ENMEDIA");
//myConnection.Open();
//SqlDataReader dr = new SqlCommand("SELECT question_text,question_id FROM otvtbl_question ", myConnection).ExecuteReader();
// listView1.Columns.Clear();
listView1.Items.Clear();
myConnection.Open();
String MyString1 = string.Format("SELECT question_id,question_text,start_time,end_time,status,repeat FROM otvtbl_question");
com = myConnection.CreateCommand();
com.CommandText = MyString1;
dr = com.ExecuteReader();
ListViewItem itmX;
//Adding the Items To The Each Column
while (dr.Read())
{
itmX = new ListViewItem();
itmX.Text = dr.GetValue(0).ToString();
var word = itmX.Text;
for (int i = 1; i < 6; i++)
{
itmX.SubItems.Add(dr.GetValue(i).ToString());
}
if (dr.GetDateTime(2) < now && dr.GetDateTime(3) > now)
{
itmX.SubItems[4].Text = "Broadcasting";
}
else if (dr.GetDateTime(3) < now)
{
string a=Convert.toString(dr.GetDateTime(3));
itmX.SubItems[4].Text = "Expired";
String broadcast = string.Format("UPDATE otvtbl_question SET status='EXPIRED' where start_time='{6}'",a );
//Execute the SqlCommand
com = new SqlCommand(broadcast, myConnection);
com.ExecuteNonQuery();
}
else
{
itmX.SubItems[4].Text = "Not Expired";
}
listView1.Items.Add(itmX);
}
dr.Close();
myConnection.Close();
}
catch (Exception ex)
{
//Error Message While Fetching
MessageBox.Show("Error While Fetching the data From the DataBase" + ex);
}
finally
{
//Closing The Connection
if (dr != null)
dr.Close();
if (myConnection.State == ConnectionState.Open)
myConnection.Close();
}
}
In this code the status column has to be updated every time the user load the form. While the form is loading it has to check the whether the start_time is greater than current time. If it is greater than the status column has to display NOT EXPIRED otherwise it has to show EXPIRED. The problem is that I am able to show the EXPIRED and NOT EXPIRED values in Status column by comparing the time, but I want to save the EXPIRED and NOT EXPIRED values in the database while it shows the values in the status column. I have tried to update it using following command:
String broadcast = string.Format("UPDATE otvtbl_question SET status='EXPIRED' where start_time='{6}'",a );
//Execute the SqlCommand
com = new SqlCommand(broadcast, myConnection);
com.ExecuteNonQuery();
But it says:
DataReader has to be closed before Updating the data.
I even tried to close the datareader and tried to update and it says different errors as:
Index (zero based) must be greater than or equal to zero and less than size of the argument list
Any suggestions?
You should implement the using statement. This will resolve the issue. Following are the blocks where the using statement should be implemented.
Sql Connection
DataReader
Moreover we should use parameterized queries. Below is the sample code.
using (System.Data.SqlClient.SqlConnection con = new SqlConnection("YourConnection string")) {
con.Open();
SqlCommand cmd = new SqlCommand();
string expression = "Parameter value";
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "Your Stored Procedure";
cmd.Parameters.Add("Your Parameter Name",
SqlDbType.VarChar).Value = expression;
cmd.Connection = con;
using (IDataReader dr = cmd.ExecuteReader())
{
if (dr.Read())
{
}
}
}
Here is the IDisposable example as requested by you.
IDisposable

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