1. Lập trình SQL Server với.Net Vu Tuyet Trinh trinhvt-fit@mail.hut.edu.vn Hanoi University of Technology 1

2. Microsoft What is.NET? An application development platform from Microsoft Rapidly develop secure and robust software Web and Windows Full support for object-oriented programming

3. Microsoft 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)

4. Microsoft Outline .Net Framework ADO.net CLR Integration Enabling CLR Integration CLT Integration: Pros & Cons

5. Microsoft.Net Framework Web Forms Web Services ADO.NET and XML Base Framework Classes Common Language Runtime Win Forms …

6. Microsoft DataReaderDataSetDataAdapter ADO.NET Architecture CommandTransactionConnection Command Builder Disconnected Layer Connected Layer Data Layer

7. Microsoft 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

8. Microsoft 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)

9. Microsoft 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

10. Microsoft 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;

11. Microsoft 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

12. Microsoft DataAdapter SelectCommand InsertCommand UpdateCommand DeleteCommand TableMapping DataAdapter CommandBuilder DataSet Fill Update Fill Update

13. Microsoft DataSet Interaction SqlDataAdapter DB XmlTextReader XmlTextWriter XML File DataControlDataGrid ComboBox ComboBox… DataView Filter/Sort

14. Microsoft Outline .Net Framework  ADO.net CLR Integration Enabling CLR Integration CLT Integration: Pros & Cons

15. Microsoft 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

16. Microsoft 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 … )

17. Microsoft Where do we use CLR code? 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

18. Microsoft Enabling CLR Integration Enabled on an instance SQL Script  Execute sp_configure ‘clr enabled’, ‘1’  Sp_reconfigure Surface Area Configuration (features)

19. Microsoft 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...

20. Microsoft 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

21. Microsoft 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

22. Microsoft 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

23. Microsoft 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 }

24. Microsoft Managed Stored Procedure DML Uses the CREATE PROCEDURE call Adds AS EXTERNAL NAME to specify CLR SP Example CREATE PROCEDURE AS EXTERNAL NAME.. CREATE PROCEDURE MyProc AS EXTERNAL NAME AssemlyExample.SqlClr.MyProc

25. Microsoft 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; }

26. Microsoft DML must match the parameters CREATE PROCEDURE InputProcedure @number int AS EXTERNAL NAME AssemlyExample.SqlClr.InputProcedure CREATE PROCEDURE OutputProcedure @number int OUTPUT AS EXTERNAL NAME AssemlyExample.SqlClr.OutputProcedure CREATE PROCEDURE InOutProcedure @number int OUTPUT AS EXTERNAL NAME AssemlyExample.SqlClr.InOutProcedure -- NOTE: You don’t specify ReturnParameters CREATE PROCEDURE ReturnProcedure AS EXTERNAL NAME AssemlyExample.SqlClr.ReturnProcedure

27. Microsoft Managed Functions Using similar DML Syntax: CREATE FUNCTION ( ) RETURNS AS EXTERNAL NAME.. CREATE FUNCTION Addition ( @x int, @y int ) RETURNS int AS EXTERNAL NAME ExampleYukon.SqlClr.Addition

28. Microsoft Managed Functions (2) Code is similar to Stored Procedures  [SqlFunction] Parameters Helps SQL Server know what the function does  IsDeterministic  IsPrecise  DataAccess  SystemDataAccess [SqlFunction] public static int Addition(int x, int y) { return x + y; }

29. Microsoft Managed Triggers DML Triggers DDL Triggers CREATE TRIGGER ON AS EXTERNAL NAME.. CREATE TRIGGER AddContact ON author FOR INSERT AS EXTERNAL NAME AssemlyExample.SqlClr.AddContact CREATE TRIGGER ON AS EXTERNAL NAME.. CREATE TRIGGER AddUser ON DATABASE FOR CreateUser AS EXTERNAL NAME AssemlyExample.SqlClr.AddUser

30. Microsoft TriggerContext ColumnsUpdates to see what columns changed public static void AddAuthor() { SqlTriggerContext ctx = SqlContext.TriggerContext; if (ctx.TriggerAction == TriggerAction.Insert) { string msg = ""; // Get the data associated with Event for (int x = 0; x < ctx.ColumnCount; ++x) { msg += string.Format("Column {0} {1} been updated{2}", x, (ctx.IsColumnsUpdated(x) ? "has" : "has not"), Environment.NewLine) } // Use the message to log it somewhere }

31. Microsoft Custom Aggregates Write your own MIN, MAX, COUNT  Define a CLR Type that does the aggregation  Use DML command to register CREATE AGGREGATE ( @param ) RETURNS EXTERNAL NAME. CREATE AGGREGATE CustomAverage ( @value float ) RETURNS float EXTERNAL NAME AssemlyExample.CustomAverage

32. Microsoft Custom Aggregates - CLR Class called during the aggregation Not just passed a set of values, but one at a time Must be serializable (for intermediate results) Must implement known methods  Init Called at the start of the aggregation of fields  Accumulate Called once for each row being aggregated. It is passed the value from the column being aggregated.  Merge Called to merge a temporary result into the aggregate  Terminate Called at the end of the aggregation process to retrieve the result of the aggregation.

33. Microsoft Custom Average Example [Serializable] [SqlUserDefinedAggregate(Format.UserDefined, MaxByteSize = 8000)] public class CustomAverage : IBinarySerialize { SqlDouble _total = 0; ulong _totalCount = 0; public void Init() { } public void Accumulate(SqlDouble Value) { ++_totalCount; if (_total.IsNull) _total = 0; _total += Value; } public void Merge(StdDev grp) {/*...*/ } public SqlDouble Terminate() { return _total/_totalCount; } void IBinarySerialize.Read(BinaryReader r) { /*...*/ } void IBinarySerialize.Write(BinaryWriter w) { /*...*/ } }

34. Microsoft InProc Managed Provider Inside the Server, a new Provider  Very similar to SqlClient Provider  Follows Managed Provider Model  Supports IDbConnection IDbCommand IDbDataReader Etc.

35. Microsoft InProc Managed Provider (2) Dude, where’s my Connection?  In Out-of-proc ADO.NET: using (SqlConnection conn = new SqlConnection("...")) using (SqlCommand cmd = conn.CreateCommand()) { try { cmd.CommandText = "..."; conn.Open(); using (SqlDataReader rdr = cmd.ExecuteReader()) { while (rdr.Read()) { Console.WriteLine(rdr.GetString(0)); } } // Reader is disposed } finally { conn.Close() } } // using statements ensure Disposed is called

36. Microsoft InProc Managed Provider (3) InProc you can assume the connection using (SqlCommand cmd = new SqlCommand()) { cmd.CommandText = "..."; SqlContext.Pipe.ExecuteAndSend(cmd); }

37. Microsoft InProc Managed Provider (4) If you need a connection  Can create additional connections  Use “context connection=true” for current using (SqlConnection conn = new SqlConnection("context connection=true")) using (SqlCommand cmd = conn.CreateCommand()) { cmd.CommandText = @"SELECT * FROM Sales.SalesOrderHeader"; try { conn.Open(); SqlDataReader rdr = cmd.ExecuteReader(); while (rdr.Read()) total += Convert.ToDecimal(rdr["TotalDue"]); } finally { conn.Close(); }

38. Microsoft InProc Managed Provider (5) SqlContext  Used to get active server objects Pipe WindowsIdentity Etc.

39. Microsoft InProc Managed Provider (6) Returning Data  Use a Pipe to send data back to the client Use the SqlContext’s Pipe Use Execute() to Fire a Command into the pipe Use Send() to send results back from a Reader SqlCommand cmd = new SqlCommand(); cmd.CommandText = "SELECT * FROM Customer"; // Send the results to the client SqlPipe pip = SqlContext.Pipe.Execute(cmd); SqlCommand cmd = new SqlCommand(); cmd.CommandText = "SELECT * FROM Customer"; SqlDataReader rdr = cmd.ExecuteReader(); // Send the results to the client SqlContext.Pipe.Send(rdr);

40. Microsoft InProc Managed Provider (7) Returning Custom Results  Use SqlDataRecord Must create SqlMetaData to describe the result SqlMetaData[] columns = new SqlMetaData[3]; columns[0] = new SqlMetaData("ID", SqlDbType.Int); columns[1] = new SqlMetaData("Name", SqlDbType.NVarChar, 50); columns[2] = new SqlMetaData("theDate", SqlDbType.DateTime); SqlDataRecord record = new SqlDataRecord(columns); record.SetInt32(0, 1); record.SetString(1, "Bob Higgins"); record.SetDateTime(2, DateTime.Now); SqlContext.Pipe.Send(record);

41. Microsoft InProc Managed Provider (8) Return Custom Results (Multiple Rows)  Use SendResultsStart to begin  Must send all rows with SendResultsRow  Must end with SendResultsEnd // Start it SqlContext.Pipe.SendResultsStart(record); // Only primes pump SqlContext.Pipe.SendResultsRow(record); SqlDataRecord anotherRecord = new SqlDataRecord(columns); anotherRecord.SetInt32(0, 2); anotherRecord.SetString(1, "Mary Roberts"); anotherRecord.SetDateTime(2, DateTime.Now.AddDays(1)); SqlContext.Pipe.SendResultsRow(anotherRecord); // Finish ResultSet SqlContext.Pipe.SendResultsEnd();

42. Microsoft InProc Managed Provider (9) SQL Server Datatypes  Use System.Data.SqlTypes namespace  Each SqlXXXXX type is INullable  Allows Stored Procs that allow DB Nulls public static void GetContact(SqlString email) { SqlCommand cmd = new SqlCommand(); cmd.CommandText = @"SELECT FirstName, LastName FROM Person.COntact WHERE EmailAddress = @email"; cmd.Parameters.Add("@email", SqlDbType.NVarChar, 50); cmd.Parameters["@email"].Value = email; SqlContext.Pipe.ExecuteAndSend(cmd); }

43. Microsoft Managed User-Defined Datatypes Before SQL Server 2005  User Datatypes were aliases or restrictions Since SQL Server 2005  Can store CLR Type as a Datatype  Rules are embedded in the CLR Type EXEC sp_addtype N'age', N'tinyint', N'not null' GO CREATE RULE age_range AS @age >= 0 AND @age <=140 GO EXEC sp_bindrule N'age_range', N'age' GO

44. Microsoft CLR Data Type - Requirements Supports the concept of NULL Supports conversion to and from string Supports serialization Supports a default constructor Type and member conform to naming rules (128 character maximum)

45. Microsoft Creating a User-Defined Data Type DML Statement: CREATE TYPE CREATE TYPE EXTERNAL NAME. CREATE TYPE Point EXTERNAL NAME AssemlyExample.Point

46. Microsoft UDT Example [Serializable] [SqlUserDefinedType(Format.UserDefined, MaxByteSize=8)] public class Point : INullable, IBinarySerialize { bool isNull = false; int x; int y; // Required constructor public Point() : this(0, 0) { } public Point(int x, int y) { this.x = x; this.y = y; } //... }

47. Microsoft Using a UDT Use CONVERT to switch from string to type DECLARE @p as dbo.Point SET @p = Convert(dbo.Point, '3,8') SELECT @p

48. Microsoft UDT Methods Marking it with SqlMethod can expose it  IsMutator shows SQL Server that it changes itself:  Can use with the point syntax: [SqlMethod(IsMutator=true)] public void Swap() { int temp = x; x = y; y = temp; } DECLARE @p as dbo.Point SET @p = Convert(dbo.Point, '3,8') SELECT @p @p.Swap() SELECT @p

49. Microsoft Outline .Net Framework  ADO.net  CLR Integration  Enabling CLR Integration CLR Integration: Pros & Cons

50. Microsoft Benefits from CLR Integration Take advantage of the powerful.NET Framework.NET is a full-featured programming language  Supports things like “for each” loops, arrays, collections  Object Oriented programming model to organise your queries  Obtaining data from external resources The File System The Event Log A Web Service The Registry

51. Microsoft Benefits … (2) For complex calculations  Parsing strings (like the regular expression code)  User-defined types Date, time, currency, and extended numeric types Geospatial applications Encoded or encrypted data (see books online)  User-defined aggregates Powerful Intellisense and debugging Generally faster  E.g. CLR aggregate 100x faster than cursor

52. Microsoft Week points … Lots of programming for simple operations Some overhead in communicating with assemblies Remember – T-SQL is designed and optimised for data, use it! Potentially costly to rewrite logic  Companies (including us) have invested a lot in T-SQL

53. Microsoft Calling between T-SQL & SQL-CLR Having some restrictions Must only use T-SQL supported data types. Can't use inheritance or polymorphism. No equivalent of DB_NULL in.NET  can use null for reference types, but not for types like int..NET cannot easily represent either VARCHAR or TIMESTAMP .NET strings are Unicode, the equivalent of NVARCHAR. The CLR decimal type is not the same as SQL_DECIMAL.

54. Microsoft Summary Need to manipulate data before it is displayed  Use.NET code and SQLCLR Need to do set-based operations such as pivoting  Use T-SQL Need to do extensive computation or custom algorithms  Use.NET code and SQLCLR Have many complex store procedure .NET code and SQLCLR

55. Microsoft

56. Demo