Weird behaviour when running an INSERT command (C# and XLSX) - c#

Somehow I cannot understand what is going on with a command I am using.
Basically I want to insert data into an EXCEL file as following:
string ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=scriptsdb.xlsx;Extended Properties=\"Excel 12.0;ReadOnly=False;HDR=Yes;\"";
OleDbConnection objConn = new OleDbConnection(ConnectionString);
string sSQLQuery = "INSERT INTO [Plan1$] ([ID], [NAME], [DESCRIPTION], [SQL_CODE]) VALUES ('" + NextID + "','" + txtbxName.Text + "','" + txtbxDescription.Text + "','" + txtboxSQL.Text + "')";
OleDbCommand cmd = new OleDbCommand(sSQLQuery, objConn);
objConn.Open();
cmd.ExecuteNonQuery();
Now check it out. Sometimes it works (record is added) and sometimes I get an error message (Operation must use an updateable query).
As weird as it might sound I just get the error message when the Text fields have just one word. e.g: "TEST". As soon as I change it to "TEST ONE" it works fine. If I try to save it with two words right from the beginning it works.
Any idea what I might be doing wrong?
Thanks!!

Note: change INSERT INTO [Plan1$] to INSERT INTO[Sheet1$].
Working code.
class Program
{
static void Main(string[] args)
{
string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source="+"C:\\Users\\123\\Desktop\\plan1.xlsx;"+"Extended Properties=\"Excel 12.0;ReadOnly=False;HDR=Yes\";";
// here you can use your text box or from
// where ever you access the data to be inserted
// into the that Excel file sheet
string selectString = "INSERT INTO [Sheet1$] ([ID], [NAME], [DESCRIPTION], [SQL_CODE]) VALUES ('1','maziz','Not working','selectfrom you')";
OleDbConnection con = new OleDbConnection(connectionString);
OleDbCommand cmd = new OleDbCommand(selectString, con);
try
{
con.Open();
cmd.ExecuteNonQuery();
Console.WriteLine("Successfully inserted the records");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
con.Close();
con.Dispose();
}
Console.ReadLine();
}
}

Related

C# Updating excel database and inserting record while adding items

so I have this program which when I press a button inserts a record into an excel spreadsheet with, the columns, being , customer, product, weight, dateTime. Now I want to be able to update a record if the same customer, and product occurs, but I also want to add the previous weight field with the new field, and update the time.
The problem is i'm not sure how to modify my update statement to do this.
// Load data from database, and Update database if filed already exists
DataSet ds = new DataSet();
string insertquery = "SELECT * FROM [Sheet1$] where [Customer] = '" + lblcustomername + " ' ";
OleDbConnection myConnection = new OleDbConnection(OutputDatabaseConnectionString); //define new connection object
OleDbDataAdapter mydataadapter = new OleDbDataAdapter(insertquery, myConnection); //define data adaptor and select column data from spreadsheet
mydataadapter.Fill(ds);
int i = ds.Tables[0].Rows.Count;
// If item exists in database, update it
if (i > 0)
{
try
{
System.Data.OleDb.OleDbConnection myConnection2; //create new connection object
System.Data.OleDb.OleDbCommand myCommand = new System.Data.OleDb.OleDbCommand();
String sql = null;
myConnection2 = new System.Data.OleDb.OleDbConnection(OutputDatabaseConnectionString); //define connection string
myConnection2.Open();
myCommand.Connection = myConnection2;
sql = "UPDATE [Sheet1$] SET [Net Weight(Kg)]= '" + textBox1.Text + "' WHERE [Customer] = '" + lblcustomername + "'";
myCommand.CommandText = sql;
myCommand.ExecuteNonQuery();
myConnection2.Close();
myConnection2.Close(); //close connection
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
// if it doesn't exist update database
try
{
System.Data.OleDb.OleDbConnection myConnection1; //create new connection object
System.Data.OleDb.OleDbCommand myCommand = new System.Data.OleDb.OleDbCommand();
String sql = null;
myConnection1 = new System.Data.OleDb.OleDbConnection(OutputDatabaseConnectionString); //define connection string
myConnection1.Open();
myCommand.Connection = myConnection1;
sql = sql = "INSERT INTO [Sheet1$] ([Customer],[Product],[Net Weight(Kg)], [DateTime]) VALUES('" + lblcustomername.Text + "','" + lblproductname.Text + "','" + textBox1.Text + "','" + (DateTime.Now).ToString() + "')";
myCommand.CommandText = sql;
myCommand.ExecuteNonQuery();
myConnection1.Close();
myConnection1.Close(); //close connection
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}

How to create connection between MySQL table to query in C#

I wrote the query for inserting data to MySQL table "Persons":
SqlConnection con = new SqlConnection();
try
{
String insert = "INSERT INTO Persons (id,Name,Surname,Address,Phone) VALUES ('" + txtId.Text + "','" + txtName.Text + "','" + txtSurname.Text + "','" + txtAddress.Text + "','" + txtPhone.Text + "')";
con.Open();
SqlCommand cmd = new SqlCommand(insert,con);
cmd.ExecuteNonQuery();
con.Close();
}
catch
{
MessageBox.Show("Id is not valid");
}
But it's not working. I have one connection for the whole database, but it's not working for a specific table. How I can create a connection between specific table to query in C#?
What is it? SqlConnection con = new SqlConnection() you need to pass a connection string which comprises DBname, username, pasword, server name ... etc; you are not passing those information anywhere then how can you expect it to connect to your database without having the information.
Pass the connection string either in constructor or using the property.
SqlConnection con = new SqlConnection(connection_string)
(OR)
SqlConnection con = new SqlConnection();
con.ConnectionString = connection_string;
There are different ways to insert data into the tables. I suggest to use parametrized sql query to keep safe from malicious occurrence.
Firstly you should have a ConnectionString something like this:
string connectionString = "Persist Security Info=False;User ID=UserName;Password=YourPassword;Server=ServerName";
And than:
using (SqlConnection connection = new SqlConnection(connectionString))
{
SqlCommand cmd = new SqlCommand("INSERT INTO TableName (Col1, Col2, ColN) VALUES (#Col1, #Col2, #ColN)");
cmd.CommandType = CommandType.Text;
cmd.Connection = connection;
cmd.Parameters.AddWithValue("#Col1", txtName.Text);
cmd.Parameters.AddWithValue("#Col2", txtPhone.Text);
cmd.Parameters.AddWithValue("#ColN", txtAddress.Text);
connection.Open();
cmd.ExecuteNonQuery();
}
Try this code. Please edit your credentials before trying.
Replace localhost with SQL server instance name, user id with your MySQL server instance user id, password with your MySQL server instance password and testdb with your database name. It should work fine.
string connectionString = #"server=localhost;user id=admin;password=admin;database=testdb;";
SqlConnection con = new SqlConnection(connectionString);
try
{
String insert = "INSERT INTO Persons (id,Name,Surname,Address,Phone) VALUES ('" + txtId.Text + "','" + txtName.Text + "','" + txtSurname.Text + "','" + txtAddress.Text + "','" + txtPhone.Text + "')";
con.Open();
SqlCommand cmd = new SqlCommand(insert,con);
cmd.ExecuteNonQuery();
con.Close();
}
catch
{
MessageBox.Show("Id is not valid");
}

Error connecting to MS Access database from C# Winform

I'm a student programmer and I'm writing this software for a small school, it's my first program, the code below is giving me the error
syntax error in insert into statement
I know the connection string is not the problem because I use it for inserting into two other tables with the same insert into format.
I am using an access database.
The offending code is
connection.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = connection;
command.CommandText = "insert into studentBillRecords (StudentName, Department, Level, AccomodationStatus, SemesterBill, PreviousBalance, TotalBill) values ('"+ txtSRstudentName.Text + "', '" + cmbSRDepartment.Text + "', '" + cmbSRLevel.Text + "', '" + cmbSRAccomodationStatus.Text + "', '" + txtSRSemesterBill.Text + "', '" + txtSRPreviousBalance.Text + "', '" + txtSRTotalBill.Text + "')";
MessageBox.Show(command.CommandText);
command.ExecuteNonQuery();
connection.Close();
This same code with different table names, column names and input works with another table in the same database but won't work with this one.
Level is a reserved keyword in access.
Also use Parameters instead of concatinating string. Try this code out, it makes it safer and easier to read:
Note: I changed the name of the column Level to StudentLevel which, I assume, doesn't exist yet in your table.
try
{
using (OleDbConnection connection = new OleDbConnection("my connection string"))
{
//Open connection
connection.Open();
//Create new command
OleDbCommand cmd = new OleDbCommand();
cmd.Connection = connection;
//Create command text
cmd.CommandText =
"INSERT INTO studentBillRecords " +
"(StudentName, Department, StudentLevel, AccomodationStatus, SemesterBill, PreviousBalance, TotalBill) VALUES " +
"(#StudentName, #Department, #StudentLevel, #AccomodationStatus, #SemesterBill, #PreviousBalance, #TotalBill)";
// Add names paremeters
cmd.Parameters.AddRange(new OleDbParameter[]
{
new OleDbParameter("#StudentName", txtSRstudentName.Text),
new OleDbParameter("#Department", cmbSRDepartment.Text),
new OleDbParameter("#StudentLevel", cmbSRLevel.Text),
new OleDbParameter("#AccomodationStatus", cmbSRAccomodationStatus.Text),
new OleDbParameter("#SemesterBill", txtSRSemesterBill.Text),
new OleDbParameter("#PreviousBalance", txtSRPreviousBalance.Text),
new OleDbParameter("#TotalBill", txtSRTotalBill.Text)
});
//Execute Query
cmd.ExecuteNonQuery();
//No need to close because we are using "using"
}
}
catch (OleDbException ex)
{
//If an exception occurs let's print it out to console
Console.WriteLine("ERROR: " + ex.ToString());
throw;
}
For information on how to change the column name read this:
https://msdn.microsoft.com/en-us/library/bb177883(v=office.12).aspx
"Level" is a keyword in MS Access, may be that is why this issue occurs try quoting it like [Level]
List Of MS Access Keywords

Using ExecuteReader to return a primary key

How Do I Find the ID from the first query and return this value so it can be inserted into query2? This is the code that needs done when a user completes a form on front end. I need to populate two tables and they will relate through the ID "StoryID" which is a primary key that is automatically created.
protected void Upload2_Click(object sender, EventArgs e)
{
userStoryForm.Visible = false;
info.Text = "You have successfully added a new user story.";
String connectionString = WebConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
String usernameData = username.Text.ToString();
int captureProjectID = Convert.ToInt32(Request.QueryString.Get("ProjectID"));
String storyno = StoryNoTextBox.Text;
String userstory = StoryTextTextBox.Text;
//Create connection
SqlConnection myConnection = new SqlConnection(connectionString);
//open connection
myConnection.Open();
String query = "INSERT INTO UserStories (StoryNo, StoryText, ProductOwner, ProjectID) " +
"VALUES ('" + storyno + "','" + userstory + "','" + usernameData + "','" + captureProjectID + "')" +
"SELECT SCOPE_IDENTITY() AS StoryID;";
SqlCommand myCommand = new SqlCommand(query, myConnection);
// Call GetOrdinal and assign value to variable.
SqlDataReader reader = myCommand.ExecuteReader();
int StoryIDData = reader.GetOrdinal("StoryID");
// Use variable with GetString inside of loop.
while (reader.Read())
{
Console.WriteLine("StoryID={0}", reader.GetString(StoryIDData));
}
// Call Close when done reading.
reader.Close();
//insert productowner, projectID and storyID into ProductBacklog table
String query2 = "INSERT INTO ProductBacklog (ProductOwner, ProjectID, StoryID) VALUES ('" + usernameData + "', #returnProjectID,'" + StoryIDData + "')";
SqlCommand myCommand2 = new SqlCommand(query2, myConnection);
myCommand2.Parameters.AddWithValue("#returnProjectID", captureProjectID);
//close connection
myConnection.Close();
}
}
Most important - use parameters in your SQL command. Never concatenate strings like that. You're asking for an SQL injection attack.
string query = #"
INSERT INTO UserStories (StoryNo, StoryText, ProductOwner, ProjectID)
VALUES (#storyno, #userstory, #usernameData, #captureProjectID)
SELECT CAST(SCOPE_IDENTITY() AS INT)";
SqlCommand myCommand = new SqlCommand(query);
myCommand.Parameters.Add("#storyno", DbType.String).Value = storyno;
...
To get the returned id, use ExecuteScalar():
int StoryIDData = (int)myCommand.ExecuteScalar();
Also, you don't dispose your resources correctly. If an exception is thrown in the method, the SQLConnection will not be closed. You should put it in a using statement.

Excel from string data to integer

I add data from a text to excel with insert into, but it's always show string format. I want it float format(0.2, 1, 20) and I cant change them in excel (for example a coloumn in one time, only it could be changed by one by for all cells). I tried tryparse or converttoint32 func. but nothing change in excel, the numbers are still in text format..
public void ExcelWrite(string date, string station_name, string station_no, string xvaluee)
{
try
{ float j;
xvaluee=xvaluee.Trim();
float.TryParse(Valuee, out j);
string szConn = #"Provider=Microsoft.ACE.OLEDB.12.0;Data Source='C://data.xls';Extended Properties='Excel 8.0;HDR=YES'";
OleDbConnection conn = new OleDbConnection(szConn);
conn.Open();
OleDbCommand cmd = new OleDbCommand("INSERT INTO [Sayfa1$]([Station_No],[Station_Name],[Date],[Valuee]) VALUES('" + station_no + "','" + station_name + "','" + date + "','" + j + "')", conn);
cmd.ExecuteNonQuery();
conn.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
since you adding '' for each parameter all will take as strings
use Parameters as below
using(OleDbConnection cn = new OleDbConnection(szConn ))
{
cn.Open();
OleDbCommand cmd1 = new OleDbCommand("INSERT INTO [Sayfa1$]([Station_No],[Station_Name],[Date],[Valuee]) VALUES(?,?,?,?)", cn);
cmd1.Parameters.AddWithValue("#p1", station_no );
cmd1.Parameters.AddWithValue("#p2", station_name );
cmd1.Parameters.AddWithValue("#p3",date );
cmd1.Parameters.AddWithValue("#p4", j);
cmd1.ExecuteNonQuery();
}

Categories

Resources