Introduction to ADO Net and Visual Studio Database

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 Ado. Net Adapter Connection Dataset Data Consumer Command Win. Form Data. Reader Web. Form

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. • Data. Reader: It is a read-only and forward-only pointer into a table to retrieve records. • Data. Set Object: A Data. Set object can hold several tables and relationships between tables. • Data. Adapter: This the object used to pass data between the database and the dataset.

Data Providers • ODBC 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: • Control Panel /Administrative Tools/Data. Source(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: WindowsSys. WOW 64odbcad 32. exe

Define an ODBC DSN for Access Database • Download: Sales. DB 2011. accdb • Open ODBC Window • Define a System DSN to Sales. DB 2011 and name it: My. Sales. Data

SQL Server Express/ SQL Server Express Local. DB • SQL Server Express is available free from Microsoft, but it requires more computer resources. • SQL Server Express Local. DB is a light-weight version of SQL Server Express that is already installed with VS 2013.

VS Database Tools • View/Server Explorer: – For connection to ODBC data sources, Ole. DB to MS Access, and SQL Server Express • View/SQL Server Object Explorer – For connection to SQL Server Local. DB

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

Working with SQL Server Express Local. DB • View/SQL Server Object Explorer • Point to SQL Server and Right-click: – Add SQL Server • Connect to Server – Serve name: (localdb)Projects – Connect

Lab: Creating a Local. DB Database • Database Name: My. Dept • Tables: – Department: • DID, Dname, Office – Employee • EID, Ename, Sex, Salary, Hire. Date, DID

To Add a New Database • Open the Local. DB node • Right-click Databases – Add new database • Enter database name – Example: My. Dept

To Add a New Table: Department • Open the Database node: Open the My. Dept node • Right-click Tables and select: Add New Table • Change the table name to Department – CREATE TABLE [dbo]. [Department] • Define fields • 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, Hire. Date, DID • Add records

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 str. Conn = "Provider=Microsoft. ACE. OLEDB. 12. 0; Data Source=C: \CSharpexamples\Sales. DB 2011. accdb"; – Ole. Db. Connection obj. Conn = new Ole. Db. Connection(str. Conn); – obj. Conn. Open();

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 Data. Grid 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 databound 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 Local. DB database My. Dept, show records of the Employee table: – with data. Grid. View – with detail view

Items Added to the Form • Table Adapter: click smart tag – 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. – Preview data • Code view: – Form load event: • Adapter’s Fill command

Other Data Form Demos • Data. Grid View • Add /Modify/Delete records. • Read only form: – Delete Add. New, 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 data. Grid 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 data. Grid’s Data. Source property to the relation (shown under the parent table’s binding source).

Detail Form with Bound List. Box • 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 List. Box – Drag the Employee table to the form. – Bind the EID field to the Binding. Source: • Activate the Property window and click the listbox • Set the Data. SOurce property to Binding. Source • 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: – Display. Info – Enter New – Modify – Exit