SQL Server - Bài 8

Lập trình SQL Server
với .Net
Vu Tuyet Trinh

Hanoi University of Technology
1
MicrosoftMicrosoft
What is .NET?

An application development platform from Microsoft

Rapidly develop secure and robust software

Web and Windows

Full support for object-oriented programming
MicrosoftMicrosoft
Advantages of .Net Framework

CLR – Common Language Runtime

Garbage collector, type safety, JIT, …

Language integration

C#, VB.net, …

Built-in support for open standards

SOAP, …


Simple development, simple deployment

Supporting entity data model (ADO.net & entity framework)
MicrosoftMicrosoft
Outline
√
.Net Framework

ADO.net

CLR Integration

Enabling CLR Integration

CLT Integration: Pros & Cons
MicrosoftMicrosoft
.Net Framework
Web
Forms
Web
Services
ADO.NET and XML
Base Framework Classes
Common Language Runtime
Win
Forms
…
MicrosoftMicrosoft
DataReader
DataSet

DataAdapter
ADO.NET Architecture
Command
Transaction
Connection
Command
Builder
Disconnected
Layer
Connected
Layer
Data
Layer
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ADO.NET Managed Provider
System.data.dll
+{System.data}
….
IDbConnection
IDbCommand
IDataReader
IDbTransaction
IDbDataAdapter
….
System.data.dll
+{System.data.SqlClient}
….
SqlConnection
SqlCommand
SqlDataReader

SqlTransaction
SqlDataAdapter
SqlCommandBuilder
Warning: There is no IDbCommandBuilder
MicrosoftMicrosoft
DataReader

Fast Forward-Only/Read-Only streams of data

Returned by IDbCommand.ExecuteReader(...)

Data is not cached on the client-side

Must be closed explicitly

Not serializable

Cannot be inherited (sealed class)
MicrosoftMicrosoft
DataSet

In-memory cache of data

Relational view of data

Data source agnostic

Keeps track of changes

Contains an XSD schema


MarshalByValue object
DataSet
Schema
Relation
Table
Column
Constraint
Row
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TypedDataSet

Without TypedDataSet
Without TypedDataSet

With TypedDataSet
With TypedDataSet

Code is more readable

Introduces compile-time checking

Intellisense under Visual Studio
dataset.Tables[0].Rows[0][1] = 1023;
dataset.Tables[“Orders”].Rows[0][“CustomerID"] = 1023;
dataset.Orders[0].CustomerID = 1023;
MicrosoftMicrosoft
Generated TypedDataSet
Class OrdersDataSet: DataSet {
InitClass() {

// create relations, constraints
}
class OrdersDataTable: DataTable {
void AddOrdersRow(OrderRow row)
void AddOrderRow(int OrderID, int CustomerID, ..)
OrderRow FindOrderByID(int OrderID)
OrderRow NewOrderRow()
}
class OrdersRow: DataRow {
int OrderID {get; set}
int CustomerID {get; set}
.....
}
……
}
Orders
OrdersDetails
Tables[0]
Tables[1]
DataSet
DataSet
MicrosoftMicrosoft
DataAdapter
SelectCommand
InsertCommand
UpdateCommand
DeleteCommand
TableMapping
DataAdapter
DataAdapter

CommandBuilder
DataSet
Fill
Update
Fill
Update
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DataSet Interaction
SqlDataAdapter
DB
XmlTextReader
XmlTextWriter
XML
File
DataControl
DataControl
DataGrid
DataGrid
ComboBox
ComboBox…
DataView
DataView
Filter/Sort
MicrosoftMicrosoft
Outline
√
.Net Framework
√
ADO.net


CLR Integration

Enabling CLR Integration

CLT Integration: Pros & Cons
MicrosoftMicrosoft
CLR Integration

Brand new since SQL Server 2005
(Standard and Express)

Write database queries using .NET

Supporting Any .NET language (C#, VB, C++)

Creating and debugging using VS 2005 IDE
MicrosoftMicrosoft
What can we do with CLR code?

Common T-SQL objects can be implemented in CLR code

User defined functions (and table valued functions)

Stored procedures

Triggers

Additional objects can be implemented in CLR code

User Defined Types


User Defined Aggregates (MAX, MIN, SUM … )
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Where do we use CLR code?
Round trip Round trip

“Distance” between the code and the data

Scale up/out possibilities of different tiers

Abstraction of the database technology

Security requirements

Set-based versus procedural code

Possibilities for using shared code libraries in multiple tiers
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Enabling CLR Integration

Enabled on an instance

SQL Script

Execute sp_configure ‘clr enabled’, ‘1’

Sp_reconfigure

Surface Area Configuration (features)
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Assembly Management

Adding an assembly from file

Note: must have permissions (NT Security)

Adding an assembly from bitstream
CREATE ASSEMBLY AssemlyExample
FROM 'd:\AssemlyExample.dll'
CREATE ASSEMBLY AssemlyExample
FROM
0x4D5A90000300000004000000FFFF0000B8000000000000...
MicrosoftMicrosoft
Code Access Security for Assemblies
3 Code Access Security (CAS) Buckets

SAFE

Access to the CLR only

No access to external resources, thread management, unsafe code or
interoper

EXTERNAL_ACCESS

Access to external systems through the .NET Framework

E.g. EventLog, FileSystem and Network

No access unsafe or interop


UNSAFE

No restrictions; similar to extended stored procedures
MicrosoftMicrosoft
DML Assembly Commands for CAS

SAFE
CREATE ASSEMBLY AssemlyExample
FROM 'd:\AssemlyExample.dll'
WITH PERMISSION_SET=SAFE

EXTERNAL_ACCESS
CREATE ASSEMBLY AssemlyExample
FROM 'd:\AssemlyExample.dll'
WITH PERMISSION_SET=EXTERNAL_ACCESS

UNSAFE
CREATE ASSEMBLY AssemlyExample
FROM 'd:\AssemlyExample.dll'
WITH PERMISSION_SET=UNSAFE
MicrosoftMicrosoft
Managed Code

Code isn’t available by default

Must register functions, stored procedures, etc.

Code is not available by default


Registration takes certain permissions to allow

Attributes

Hints to VS about how to deploy

[SqlProcedure]

[SqlFunction]

[SqlUserDefinedType]

[SqlUserDefinedAggregate]

….

Also used at runtime for behaviors of objects
MicrosoftMicrosoft
Managed Stored Procedures

To expose a Stored Procedure:

The containing class must be public

The exposed method must be public

The exposed method must be static
public class SqlClr {
public static void MyProc() {
// Put your code here

}
}
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Managed Stored Procedure DML

Uses the CREATE PROCEDURE call

Adds AS EXTERNAL NAME to specify CLR SP

Example
CREATE PROCEDURE <Procedure Name>
AS EXTERNAL NAME <Assembly Identifier>.<Type Name>.<Method Name>
CREATE PROCEDURE MyProc
AS EXTERNAL NAME AssemlyExample.SqlClr.MyProc
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Stored Procedure Parameters
// Input Parameter
public static void InputProcedure(int number) {
}
// Output Parameter
public static void OutputProcedure(out int number) {
number = 42;
}
// In/Out Parameter
public static void InOutProcedure(ref int number) {
number = 42;
}
// Return Parameter
public static int ReturnProcedure() {
return 42;

}