Introduction to ADO.Net and Visual Studio Database Tools ISYS 512

Database Processing Querying database Updating database: Insertion, deletion, modification

Steps to Retrieve Data Establishes a connection to the database. Executes query commands against the database. SQL Select commands Process the returned data.

Steps to Update Data Establishes a connection to the database. Executes update commands against the database. SQL Insert, Delete, Update commands Receive confirmation of completion.

ADO.Net: Connected and Disconnected Data Processing The ADO.Net environment can be categorized into connected and disconnected environments. A connected environment requires a constant connection to transfer data between the client application and the data source. A disconnected environment retrieves data and performs modification without a constant connection to the data source.

ADO.Net Classes

ADO.Net Classes and Data Consumer Adapter Dataset Data Consumer WinForm Connection Command WebForm DataReader

ADO.NET Objects Connection Object: Represent a connection to the database. Command Object: The command object allows us to execute a SQL statement or a stored procedure. DataReader: It is a read-only and forward-only pointer into a table to retrieve records. DataSet Object: A DataSet object can hold several tables and relationships between tables. DataAdapter: This the object used to pass data between the database and the dataset.

Data Providers Etc. ODBC Provider OLE DB Provider SQL Server Provider Open Database Connectivity A driver manager Used for relational databases OLE DB Provider OLE DB interfaces provide applications with uniform access to data stored in diverse information sources, or data stores. MS Access (accdb) SQL Server Provider Oracle Provider Etc.

Using ODBC Windows 7: Three types of data source names, DSN Control Panel /Administrative Tools/DataSource(ODBC) Three types of data source names, DSN User DSN: usable only by you and only on the machine currently using. System DSN: Any one using the machine can use. File DSN: Can be copied and used by other computers with the same driver installed. Note: For 32 bit software, you have to open the ODBC panel from C:\Windows\SysWOW64\odbcad32.exe

Define an ODBC DSN for Access Database Download: SalesDB2011.accdb Open ODBC Window Define a System DSN to SalesDB2011 and name it: MySalesData

SQL Server Express/ SQL Server Express LocalDB SQL Server Express is available free from Microsoft, but it requires more computer resources. SQL Server Express LocalDB is a light-weight version of SQL Server Express that is already installed with VS 2012, and it does not bring heavy workload on development machines

VS Database Tools View/Server Explorer: For connection to ODBC data sources, OleDB to MS Access, and SQL Server Express View/SQL Server Object Explorer For connection to SQL Server LocalDB

Connect to Access Database using OLE DB From Server Explorer, right-click Add Connection: Microsoft Access Database File (OLE DB) Browse for database Test Connection Tools/Connect to database

Connect to Access Database using ODBC From Server Explorer: right-click Add Connection Click Change Microsoft Access ODBC Data source Select DSN from the dropdown list Test Connection

To Start SQL Server Express LocalDB View/SQL Server Object Explorer Point to SQL Server and Right-click: Add SQL Server Connect to Server Serve name: (localdb)\v11.0 Connect

Lab: Creating a LocalDB Database Database Name: MyDept Tables: Department: DID, Dname, Office Employee EID, Ename, Sex, Salary, HireDate, DID

To Add a New Database Open the LocalDB node Right-click Databases Add new database Enter database name Example: MyDept

To Add a New Table: Department Open the Database node: Open the MyDept node Right-click Tables and select: Add New Table Change the table name to Department CREATE TABLE [dbo].[Department] Click Update; then click Update Database

To Add Records Open the Tables node Right-click the table name (Department) and select View Data

To Modify Table Design Point and right-click the table name: Select: View/Designer Change the CREATE TABLE command Or Change the design with the designer

Add Employee Table Right-click Tables and select Add Table: EID, Ename, Sex, Salary, HireDate, DID

Working with SQL Server Express Starting SQL Server: Control Panel/Administrative Tools /Services/SQLServer(SQLExpress) SQL Server database file extension: mdf Default database folder: A SQL Server file: testSQLServer.mdf C:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\testSQLServer.mdf

Creating SQL Server Database From Server Explorer, right click data connection and choose: Create new SQL Server Database Server name: LocalServerName\SQLExpress Ex: David-PC\SQLExpress Add new table: Right click Tables and choose Add New Table Define table’s fields Add rows: Right click the table name and choose Show table data.

Create a New SQL Server Database: EmployeeDB Add a new table: EmployeeTable EID Char 10 Ename Char 30 Sex Char 1 Salary Numeric (10,2) HireDate Date Enter data

Three Ways to Create ADO.Net Objects 1. Automatically generated when creating data bound form. Form wizard 2. Using Data Adapter Wizard 3. Using code: Example: string strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\SalesDB2007.accdb"; OleDbConnection objConn = new OleDbConnection(strConn);

Data Binding Connect a control or property to one or more data elements. Simple binding: Use simple binding to display a field value in controls that show Data Bindings in the property window, such as text box or label. Complex binding: Use complex binding to bind more than one field to controls such as DataGrid and list box. Use the control’s Data Source and Data Member to bind the data.

Automatically Generating Data Bound Form Creating a form with ADO.Net objects and data-bound controls to display and update information in a dataset. Step 1: Add a new data source: Step 2: Select controls for table fields: Click the dropdown list next to the table’s name: Datagrid view Details Step 3: Drag the table to form.

Add Data Source Data Source window: View/Other windows/Data Source Add New Data Source From Dataset Select connection Select tables

Data Bound Form Examples Using the LocalDB database MyDept, show records of the Employee table: with dataGridView with detail view

Items Added to the Form Table Adapter: click smart tag Dataset: Add query Preview data Dataset: Edit in dataset designer Binding Source: It is an object that keeps track of position (the current row) of a data source. Code view: Form load event: Adapter’s Fill command

Other Data Form Demos DataGrid View Add /Modify/Delete records. Read only form: Delete AddNew, Delete, Save buttons from navigator bar.

Hierarchical Forms: Department/Employees Parent table/Child table Add parent table and child table to Data Source Drag the parent table and the child table to the form. Parent table uses detail view and child table uses dataGrid view Click Dataset object’s smart tag to choose Edit in Dataset Designer With the designer, right click the parent table and choose Add/Relation Change dataGrid’s DataSource property to the relation.

Detail Form with Bound ListBox Example: Employee table form with EID listbox and displays selected employee information in textboxes. Choose detail view for the Employee table. Click the dropdown list next to the EID field and click ListBox Drag the Employee table to the form. Bind the EID field to the BindingSource: Activate the Property window and click the listbox Set the DataSOurce property to BindingSource Set the Display Member property to EID

Creating A Database Application Without Programming Creating a database application to display information and update database. A main form with buttons to open data forms: DisplayInfo Enter New Modify Exit

Demo: Add Data Source from OleDB and ODBC Data source

Data Adapter Wizard – 2nd Level of Using ADO.Net Configure Data Adapter and generating a dataset: From the Data tab of the ToolBox, Drag OledbDataAdapter to the form. Use the Data Adapter Wizard to configure the Adapter. Right Click the Adapter to preview data and create dataset. Note: If OledbDataAdapter is not listed in Toolbox’s Data tab , right click ToolBox Data Tab and select Choose Item; then select OleDbDataAdapter from .Net Framework components.

Creating a Form with Bound DataGridView Configure Adapter and generate dataset. Bind DataGridView control to the table: Data Source property: DataSet Data Member property A table in the dataset In the Form Load event, use Adapter’s Fill method to load the dataset: OleDbDataAdapter1.Fill(DataSet11); Note 1: No navigation capability Note 2: View adapter’s properties and see the SQL commands.

Creating a Form with Bound Textboxes Configure Adapter and generate dataset. Select textbox’s Data Bindings property: Text: choose field from bindingSOurce object In the Form Load event, use Adapter’s Fill method to load the dataset: OleDbDataAdapter1.Fill(DataSet11) Note: No navigation capability

Using BindingSource Object to Do the Binding and Navigation It is an object that keeps track of position (the current row) of a data source. Useful properties: DataSource DataMember Position property: is the index of the current row. The index is a 0-based index, the first record has a position of 0. Methods: MoveFirst, MoveLast, MoveNext, MovePrevious AddNew AllowEdit EndEdit Current RemoveCurrent

Bind Controls to BindingSource Object Configure Adapter and generate dataset. Add BindingSource object to the form Use BindingSource object’s property window to set its DataSource and Data Member properties to the dataset object and table object. Set control’s DataBinding property to the BindingSource object.

Use BindingSource Object’s MoveNext, MovePrevious Methods Add a MoveNext button bindingSource1.MoveNext(); Add a MovePrevious button: bindingSource1.MovePrevious();

Adding AddNew and Save Button AddNew button: Use BindingSource AddNew Method: private void button3_Click(object sender, EventArgs e) { bindingSource1.AddNew(); } Save button: Use BindingSource EndEdit method and Adapter’s Update method: private void button4_Click(object sender, EventArgs e) { bindingSource1.EndEdit(); oleDbDataAdapter1.Update(dataSet2.CUSTOMER); }

Binding ListBox Example: Bind Customer Table’s CID field to a listbox. Create a Adapter for Customer table , and generate the dataset. Add ListBox and set binding properties: Data Source: Customer table Display Member: Field to display in the listbox. Value Member: the actual values for items in the list box.

Display Selected Record Bound textbox (same data source as the listbox): If the Listbox and the textbox are bound to the same BindingSource object, the textbox will automatically displays the record of the selected listbox item. Unbound textbox To display the ValueMember textBox3.Text = listBox1.SelectedValue.ToString(); To display other fields: VB with late binding Textbox1.text = ListBox1.SelectedItem(“Cname”) C# does not support late binding: No!

ListBox SelectedItem Property: (Works for VB) How to display the selected record in unbound textbox? After binding to a data source, this property return a DataRowView object. What is DataRowView? Object Browser: System.Data DataRowView: Item property is the default property To retrieve a column from a DataRowView object (use 0-based index to identity a column): ListBox1.SelectedItem.Item(1) Or: ListBox1.SelectedItem(1) Or: ListBox1.SelectedItem(“Cname”)

Using Object Browser View/Object Browser DataSet object model: System.Data DataSet Relations Tables Rows Columns Use Object Browser to study object’s properties, methods. Ex. System.Data.OleDbDataAdapter

Unbound Textbox: Navigate from Dataset to Table; from Table to Row and Field textBox3.Text = dataSet41.Tables["employee"].Rows[listBox1.SelectedIndex][1].ToString(); textBox4.Text = dataSet41.Tables["employee"].Rows[listBox1.SelectedIndex]["Salary"].ToString();

Working with SQL Server Data Adapter From the Data tab: Choose: SQLDataAdapter (If you don’t see it, right-click the Data tab and select Choose Item. Then select it from the .Net components)

DataSet and Data Adapter DataSet Object: A DataSet object can hold several tables and relationships between tables. DataAdapter: This the object used to pass data between the database and the dataset. It is an object with SQL Select, Insert, Update and Delete commands.

Creating Parent/Child Form Using DataAdapter Wizard Add two DataAdapters to the form: one for the parent table and one for the child table. Use the parent table’s DataAdapter to generate a dataset; then use the child table’s DataAdapter to generate the child table into the same dataset. Open dataset’s designer and right-click the parent table and choose Add/Relation to add a relation. Add and bind textboxes to the parent table; add dataGridView and bind its datasource property to the relation. Add navigation button’s using parent table’s BindingSource object.