CODE:::
Dim reader As Microsoft.VisualBasic.FileIO.TextFieldParser
reader = My.Computer.FileSystem.OpenTextFieldParser _
("C:\Temp\test.csv")
reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
reader.Delimiters = New String() {","}
Dim currentRow As String()
While Not reader.EndOfData
Try
currentRow = reader.ReadFields()
Dim currentField As String
For Each currentField In currentRow
MsgBox(currentField)
Next
Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
MsgBox("Line " & ex.Message & _
"is not valid and will be skipped.")
End Try
End While
Friday, January 18, 2008
Tuesday, January 15, 2008
Update dataset data back to database
This post explains how to insert, update, and delete data in a Database using Dataset.
The DataSet can be considered an in-memory cache of data retrieved from a database. The DataSet consists of a collection of tables, relationships, and constraints.
Firstly, we have to fill data into a DataSet from Database.
Secondly, when the DataSet is loaded, you can modify the data, and the DataSet will keep track of the changes made bu user.
The Add method of DataTable accepts either an array of the expected data columns, or a DataRow.
(Please note that all code is in c# language)
Step 1: Create a new Connection and SqlDataAdapter
SqlConnection myConnection = new SqlConnection("connectionStringGoesHere");
SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter("Select * from tblNews", myConnection);
DataSet myDataSet = new DataSet();
DataRow myDataRow;
Step 2: Create SqlCommandBuilder(The SqlDataAdapter does not automatically generate the Transact-SQL statements required to match changes made to a DataSet with SQL Server. But, you can create a SqlCommandBuilder object to automatically generate Transact-SQL statements for single-table updates.)
SqlCommandBuilder mySqlCommandBuilder = new SqlCommandBuilder(mySqlDataAdapter);
// Set the MissingSchemaAction property to AddWithKey because Fill will not cause primary
// key & unique key information to be retrieved unless AddWithKey is specified.
mySqlDataAdapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
mySqlDataAdapter.Fill(myDataSet, "tblNews");
Step 3: Add rows to DataTable
myDataRow = myDataSet.Tables["tblNews"].NewRow();
myDataRow["cNewsId"] = "NewID";
myDataRow["cHeading"] = "New Heading";
myDataRow["cContent"] = "Content here";
myDataSet.Tables["tblNews"].Rows.Add(myDataRow);
Step 4: Editing Row Data
We can change the data in a DataRow by accessing the DataRow. Use the index of the row in the RowsCollection accessed through the Rows property:
myDataSet.Tables["tblNews"].Rows[0]["cHeading"]="Abc";
Access a specific row by specifying the Primary Key value:
DataRow myDataRow1 = myDataSet.Tables["tblNews"].Rows.Find("124");
myDataRow1["cHeading"]="Abc";
Here "124" is the value of the Primary Key "cHeading" in the "tblNews" table.
Step 5: Deleting a record
Use Delete method to delete a Row. All changes are done in dataset until you don't explicitly update DataSet data to the Database. Use RejectChanges method of DataSet to reverse all changes made to DataSet.
myDataSet.Tables["tblNews"].Rows[0].Delete();
Note: The original and new values are maintained in the row. The RowChanging event allows you to access both original and new values to decide whether you want the edit to proceed.
SqlCommandBuilder mySqlCommandBuilder = new SqlCommandBuilder(mySqlDataAdapter);
Step 6: Finally Update DataBase
To submit the data from the DataSet into the database, use dataAdapter's Update method.
mySqlDataAdapter.Update(myDataSet, "tblNews");
A Visual Studio Solution code sample will be coming soon......
The DataSet can be considered an in-memory cache of data retrieved from a database. The DataSet consists of a collection of tables, relationships, and constraints.
Firstly, we have to fill data into a DataSet from Database.
Secondly, when the DataSet is loaded, you can modify the data, and the DataSet will keep track of the changes made bu user.
The Add method of DataTable accepts either an array of the expected data columns, or a DataRow.
(Please note that all code is in c# language)
Step 1: Create a new Connection and SqlDataAdapter
SqlConnection myConnection = new SqlConnection("connectionStringGoesHere");
SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter("Select * from tblNews", myConnection);
DataSet myDataSet = new DataSet();
DataRow myDataRow;
Step 2: Create SqlCommandBuilder(The SqlDataAdapter does not automatically generate the Transact-SQL statements required to match changes made to a DataSet with SQL Server. But, you can create a SqlCommandBuilder object to automatically generate Transact-SQL statements for single-table updates.)
SqlCommandBuilder mySqlCommandBuilder = new SqlCommandBuilder(mySqlDataAdapter);
// Set the MissingSchemaAction property to AddWithKey because Fill will not cause primary
// key & unique key information to be retrieved unless AddWithKey is specified.
mySqlDataAdapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
mySqlDataAdapter.Fill(myDataSet, "tblNews");
Step 3: Add rows to DataTable
myDataRow = myDataSet.Tables["tblNews"].NewRow();
myDataRow["cNewsId"] = "NewID";
myDataRow["cHeading"] = "New Heading";
myDataRow["cContent"] = "Content here";
myDataSet.Tables["tblNews"].Rows.Add(myDataRow);
Step 4: Editing Row Data
We can change the data in a DataRow by accessing the DataRow. Use the index of the row in the RowsCollection accessed through the Rows property:
myDataSet.Tables["tblNews"].Rows[0]["cHeading"]="Abc";
Access a specific row by specifying the Primary Key value:
DataRow myDataRow1 = myDataSet.Tables["tblNews"].Rows.Find("124");
myDataRow1["cHeading"]="Abc";
Here "124" is the value of the Primary Key "cHeading" in the "tblNews" table.
Step 5: Deleting a record
Use Delete method to delete a Row. All changes are done in dataset until you don't explicitly update DataSet data to the Database. Use RejectChanges method of DataSet to reverse all changes made to DataSet.
myDataSet.Tables["tblNews"].Rows[0].Delete();
Note: The original and new values are maintained in the row. The RowChanging event allows you to access both original and new values to decide whether you want the edit to proceed.
SqlCommandBuilder mySqlCommandBuilder = new SqlCommandBuilder(mySqlDataAdapter);
Step 6: Finally Update DataBase
To submit the data from the DataSet into the database, use dataAdapter's Update method.
mySqlDataAdapter.Update(myDataSet, "tblNews");
A Visual Studio Solution code sample will be coming soon......
Monday, January 14, 2008
Show default Text in Email Field
Details::
Show default Text in Email Field.
Like on form load show "enter email id" in email field.
On click clear this text.
on mouse out with nothing entered show again this into textbox.
Demo:
CODE::
Code:
<body><input type="text" name="email" value="Your e-mail adress" onfocus="if(this.value=='Your e-mail adress') this.value=''" onblur="if(this.value=='' ) this.value='Your e-mail adress';" />
Show default Text in Email Field.
Like on form load show "enter email id" in email field.
On click clear this text.
on mouse out with nothing entered show again this into textbox.
Demo:
CODE::
Code:
<body><input type="text" name="email" value="Your e-mail adress" onfocus="if(this.value=='Your e-mail adress') this.value=''" onblur="if(this.value=='' ) this.value='Your e-mail adress';" />
Subscribe to:
Posts (Atom)