Objectives In this lesson, you will learn to: *Identify the need for ADO.NET *Identify the features...
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Transcript of Objectives In this lesson, you will learn to: *Identify the need for ADO.NET *Identify the features...
Objectives
In this lesson, you will learn to: Identify the need for ADO.NET
Identify the features of ADO.NET
Identify the components of the ADO.NET object model Connect to a database by creating a data adapter
Access a database through a dataset
Preview the data adapter result
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
ADO.NET
Is a model used by Visual Basic .NET applications to communicate with a database for retrieving, accessing, and updating data.
Uses a structured process flow to interact with a database.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Features of ADO.NET
Disconnected data architecture — Applications connect to the database only while retrieving and updating data.
Data cached in datasets — ADO.NET is based on a disconnected data structure. Therefore, the data is retrieved and stored in datasets.
Data transfer in XML format — ADO.NET uses XML for transferring information from a database into a dataset and from the dataset to another component.
Interaction with the database is done through data commands.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
ADO.NET Object Model
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
ADO.NET Object Model
DATASET
VISUAL BASIC .NET APPLICATION (WINDOWS/ WEB FORM)
DATA PROVIDER
Accessing retrieved data
Accessing retrieved data
CONNECTION
COMMAND
DATA ADAPTER
DATA READER
Establishes connection with the database
Filling dataset with data
Transfers data to the dataset and reflects the changes made in the dataset to the database
DATABASE
Retrieves data in a read-only, forward only modeExecutes a command to retrieve data from the database
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
ADO.NET Object Model (Contd.)
Data from a database can be assessed through:
A dataset
A DataReader object
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Key Components of the ADO.NET Model
Data Provider
Is used for connecting to a database, retrieving data, and storing the data.
Is of two types:
• OLE DB data provider
• SQL Server data provider
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Components of a Data Provider
Connection
Used to establish a connection with a data source
Some commonly used properties and methods:
• ConnectionString property
•Open()method
•Close()method
• State property
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Components of a Data Provider (Contd.)
Data adapter
Creates a dataset and updates the database.
Handles data transfer between the database and the dataset through its properties and methods.
Displays the data through the process of table mapping.
Are of two types:
• SqlDataAdapter
• OleDbDataAdapter
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Components of a Data Provider (Contd.)
Data command
Is a SQL statement or a stored procedure that is used to retrieve, insert, delete, or modify data from a data source.
Is an object of the OleDbCommand or SQLCommand class.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Components of a Data Provider (Contd.)
Data reader
Is used to retrieve data from a data source in a read-only and forward-only mode.
Stores a single row at a time in the memory.
Commonly used methods:
•Read()
•Close()
•NextResult()
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Dataset
Is a disconnected, cached set of records that are retrieved from a database.
Is present as a DataSet class in the System.Data namespace.
Has its own object model.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Dataset Object Model
DataRow DataColumn
DATASET
DataRelationCollection
DataRelation
DataTableCollection
DataTable
DataRowCollection DataColumnCollection
ExtendedProperties
DataView PrimaryKey
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Problem Statement 5.D.1
The call center application needs to provide the facility of viewing the customer details for the Sales department.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Task List
Identify the data that needs to be displayed.
Identify the method for creating a data adapter.
Identify the type of dataset to be created.
Create a data adapter.
Create a dataset.
Preview the database records.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Task 1: Identify the data that needs to be displayed.
Result:
As per the given problem statement, the data to be displayed is as follows:
CustID
FName
LName
Address
Phone
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Task 2: Identify the method for creating a data adapter.
There are three methods to create a data adapter:
Manually
Through a wizard
Using the Server Explorer window
Result:
In the given problem statement, you will create a data adapter by using Data Adapter Configuration Wizard
since it lets you create a data adapter with minimum steps.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Task 3: Identify the type of dataset to be created.
Datasets are of two types:
Typed
Untyped
Typed dataset
Is derived from the DataSet class and has an associated XML schema, which is created at the time of the creation of the dataset.
Can be customized after creation.
Supports Intellisense and auto‑completion for the elements of the syntax while writing code.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Task 3: Identify the type of dataset to be created. (Contd.)
Untyped dataset
Does not have any associated XML schema, therefore, the structure of an untyped dataset is not known at the compile time.
Represents tables and columns as collections.
Does not support Intellisense and auto‑completion for the elements of the syntax.
Result:
Since the structure of the data is known at compile time, you will create a typed dataset for the given problem statement.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Task 4: Create a data adapter.
Task 5: Create a dataset.
Task 6: Preview the database records.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Problem Statement 5.P.1
An application needs to be created that allows the Diaz Telecommunications Sales Manager to preview the customer order details from the database. In addition, for each order, percentage of the cost of a product given as advance needs to be previewed.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Summary
In this lesson, you learned that:
ADO.NET is a data access programming model for accessing the data stored in a database from a .NET application.
ADO.NET has the following features:
A disconnected data architecture
Data cached in datasets
The use of XML format for data transfer
Database operations done through data commands
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Summary (Contd.)
ADO.NET consists of the following components:
Data Provider — Used for connecting to a database, retrieving data, storing the data in a dataset, and updating the database.
Data Adapter — A data adapter is integral to the working of the ADO.NET model since data transfer to and from the database is done through a data adapter.
Dataset — A dataset is a disconnected cached set of records that are retrieved from the database.
A data adapter communicates with a database through data commands. These data commands use parameters for execution.
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Summary (Contd.)
After a dataset has been created, a data adapter uses the process of table mapping to map the columns in the database table with the dataset columns.
A data adapter can be created by using any of the following methods:
Manually
Through a wizard
By using Server Explorer
Working with ADO.NET
Working with ADO.NET/Lesson 5/Slide ‹#› of 30
Summary (Contd.)
Datasets are of two types:
Typed datasets – A typed dataset is derived from the DataSet class and has an associated schema.
Untyped datasets – An untyped dataset does not have any associated XML schema. The tables and columns in an untyped dataset are represented as collections.