Chapter 7 Create, Add, Delete, and Edit Data in a Disconnected Environment

Chapter 7 Create, Add, Delete, and Edit Data in a Disconnected Environment Objectives in chapter  Create a DataSet graphically.  Create a DataSet programmatically.  Add a DataTable to a DataSet.  Add a relationship between tables within a DataSet.  Navigate a relationship between tables.  Merge DataSet contents.  Copy DataSet contents.  Create a typed DataSet.  Create DataTables.  Manage data within a DataTable.  Create and use DataViews.  Represent data in a DataSet by using XML. (NO)  Use the OleDbDataAdapter object to access an ADO Recordset or Record.  Generate DataAdapter commands automatically by using the Command-Builder object. Before we go…  Con.connectionString=“….”;  /// con.Open(); -> do not need  cmd.Connectiion=con;  cmd.CommandType="Select ", conSinhVien)  cmd.CommandText=“Select * from …”;  DataAdapter da=new DataAdapter();  Da.SelectCommand=cmd;  Dataset Ds=new Dataset();  Da.Fill(Ds);  DataGrid1.DataSource=ds.tables[0]; Chapter content  Lesson 1:Creating DataSet Objects  Lesson 2: Creating DataTable Objects.  Lesson 3: Creating DataAdapter Objects  Lesson 4: Working with Data in DataTable Objects  Lesson 6: Creating and Using DataView Objects Lesson 1: Creating DataSet Objects  DataSet Objects  Creating DataSet Objects Programmatically Lesson 1: Creating DataSet Objects  DataSet Objects  temporarily store the data  Like array, in memory Dataset structure Objective: Using in-memory database  DataSet Structure  DataTable Structure DataColumn DataRow  Build manual dataset  DataView  Example Why DataSet?  Perform database modifications  always disconnected  To transfer data between tiers have .NET framework (Linux, Unix, Windows…)  To send between computers across network by HTTP protocol in XML format  To manipulate the data without an open connection  To relate data from multiple sources  To bind data to a Windows form  Power data structure  Event an application without database, we can using dataset … instead of arraylist, array… Populating DataSets  Manual  From existing databae, using DataAdapter  Read from XML data files  Build from XSD files  But before filling dataset… … we need to know dataset structure DataSet Components  DataTable  DataColumn  DataRow  Constraint  DataRelation  DataView [...]... DataTable DataRow DataColumn Populating DataSet-Manual Construct your own DataSet (schema) 1 1 2 3 4 Create Dataset Add DataTable(s) Add DataColumn(s) to DataTable Define datatable schema Fill Data into DataTable(s) in DataSet 2 1 2 Add DataRow to DataTable Processing data in dataset … Dim ds As New DataSet , r As DataRow With ds.Tables.Add("SV") Columns.Add("id") Columns.Add("Name") End With With ds.Tables("SV")... What Is a DataAdapter Between Dataset/Datatable and Database Connect to Command and Connection Fill and Update Dataset/DataTable Disconect to Dataset/DataTable Lesson 3: Creating DataAdapter Objects How to Create DataAdapter Objects Dim SqlDataAdapter1 as New SqlDataAdapter("SELECT * FROM Shippers", NorthwindConnection) Or Dim cmd as new Command … commandtype, commandext SqlDataAdapter1.SelectCommand=cmd... Row Relation DataTable DataSet DataTable Represents one table in DataSet Are accessed using the DataSet's Tables property Collection of DataTables Using index : ds.tables(0) Using name: ds.tables(“authors”) Each DataTable has: A Columns property DataColumn DataRow DataTable DataColumn DataRow (Add,remove,removeat,Item) A Rows property (Add,remove,removeat,Item) Dim DT1 As New DataTable("TableNam Access... DataTable Objects Create a DataTable Add a DataTable to a DataSet Dim NorthwindDataset As New DataSet("NorthwindData") ' Create a new DataTable Dim CustomersTable As New DataTable("Customers") ' Add the Datatable to the Dataset's Tables collection NorthwindDataset.Tables.Add(CustomersTable) Lesson 2: Creating DataTable Objects Create Expression Columns in DataTable Objects Dim TotalPriceColumn As New DataColumn("TotalPrice",... authors.PrimaryKey = new DataColumn[] {Cid}; DataRow Class A DataRow object provides access to one row of data in a DataTable DataSet A DataTable's DataRow objects contain all the data in the DataTable Create DataTable DataColumn DataRow Table.NewRow method Can access DataRow values by providing: Column name Column number DataColumn object Core Pro./methods Item(index) : get cell value IsNull Delete DataTable... 3: Creating DataAdapter Objects DataAdapter Commands SelectCommand InserCommand UpdateCommand DeleteCommand Build 4 commands when using Dataadapter??? Lesson 3: Creating DataAdapter Objects DataAdapter Commands: manual build command Dim SqlDataAdapter1 As New SqlDataAdapter("SELECT * FROM Shippers", NorthwindConnection) Dim InsertCommand As New SqlCommand("Valid SQL Insert statement", NorthwindConnection)... "aa" r("name") = "bb" Rows.Add(r) End With DataView An custom view of a DataTable Sorting, filtering, searching, editing, and navigating the data from a DataSet Using same data memory from Datatable Each DataTable have DefaultView DataTable row1 row2 row3 SV1 SV2 SV3 Nguyen thi A Nguyen thi C Nguyen thi B row2 row3 row1 row1 row3 row2 DataView1 DataView2 Dataview Changes DataView affect DataTable automatically... Configuration Wizard Questions? Lesson 1: Creating DataSet Objects Exercise 3: Configuring Untyped DataSet Objects Questions? Lesson 2: Creating DataTable Objects Create a DataTable Add a DataTable to a DataSet Define the schema of a DataTable Add columns to a table Create expression columns Create AutoIncrementing columns Define a primary key for a table Add constraints to a table Lesson 2: Creating DataTable... Access to data- cell Table.Rows(index).Item(index) DataTable Core Pro./Methods TableName property A PrimaryKey property array of datacolumn Select(filter): datarow() End of sql NewRow DefaultView Example: Create table and dataset Ds=new DataSet(); ds.DataSetName = "BookAuthors"; Tauthors =new DataTable("Author"); Ds.Tables.add (Authors); DataTable Accessing example myDataTable.Rows(5) returns a DataRow object... Similar to column in datatable DataSet DataTable DataColumn DataRow Doesn’t have Value property Core Pro / methods ColumnName DataType DataTable Ex Gettype(integer) AllowDBNull AutoIncrement DefaultValue Unique ReadOnly DataRow DataColumn Example DataColumn Cid = authors.Columns.Add("ID",gettype(integer)); Cid.AutoIncrement = true; DataColumn Cname = authors.Columns.Add("Name", gettype(String)); authors.PrimaryKey . Chapter 7 Create, Add, Delete, and Edit Data in a Disconnected Environment Objectives in chapter  Create a DataSet graphically.  Create a. DataAdapter();  Da.SelectCommand=cmd;  Dataset Ds=new Dataset();  Da.Fill(Ds);  DataGrid1.DataSource=ds.tables[0]; Chapter content  Lesson 1:Creating DataSet Objects  Lesson 2: Creating DataTable Objects.  Lesson