Sql Server - Apresentação
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SQL Server .NET programmability allows developers to write database logic using any .NET language like C# and VB.NET. The .NET runtime is hosted inside SQL Server to enable running verified managed code. Developers can create functions, stored procedures, triggers and user-defined types that leverage the full .NET framework and provide the same data access model as middle-tier code using ADO.NET. This provides a richer programming model for the database while maintaining safety, security, and performance.
Sql Server - Apresentação
- 1. SQL Server™ .NET Programmability José A. Blakeley Architect SQL Server Background l Transact SQL (T -SQL) Ø Ø SQL Server’s database programming language Includes: § § l SQL DDL, SQL DML Variables, assignment, iteration, procedures, functions .NET Platform Ø .NET runtime (Common Language Runtime) § § § Ø Ø Verifiable Intermediate Language Managed memory – garbage collection Multiple languages (e.g, C#, C++, Cobol) (e.g , Frameworks library (e.g., GUI, Files, XML) Assemblies – New Dynamic Link Libraries § § Contain code + metadata (class definitions, assembly dependencies) Unit of code deployment, security, versioning PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 1
- 2. Outline l l Motivation Basic Infrastructure Ø Ø Ø l SQL features Ø Ø Ø l Hosting overview Data access inside process: ADO.NET SQL types Server assemblies Functions, procedures, triggers Types and aggregates Summary Motivation l Broaden the set of languages for running datadata -intensive business logic in server Ø Ø Ø Ø Ø l Packaged as .NET assemblies Ø l Verifiable, secure Deployed to SQL Server as Ø l IT Developers and ISVs Multiple languages: Visual Basic ®, C#, C++, J#, … Same mid - and server -tier data access model midserverSame tools: IDE, project model, debugging, … TransactTransact-SQL still supported Functions, procedures, triggers, types Basis for SQL Server Extensibility PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 2
- 3. Development Steps VB, C#, C++ VS Project Build Runtime hosted inside SQL Server SQL Queries: select sum(tax(sal,state) sum(tax(sal,state) ) from Emp where county = ‘King’ Assembly: “TaxLib.dll” TaxLib.dll” SQL Data Definition: create assembly … create function … create procedure … create trigger … create type … SQL Server Basic Infrastructure l Hosting common language runtime inside SQL Server Ø Ø Ø l Data access in process Ø Ø l 4Ss: Safety, security, scalability, speed Run verified, type-safe code inside typeprocess Multiple languages Based on ADO.NET Same data access programming model as middle -tier middle- SQLTypes Ø SQL type semantics in managed code PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 3
- 4. Hosting .NET Runtime l Safety Ø Prevent user code from corrupting the server process § Ø Use runtime code permissions to control user code when calling § l Verifiable code Unmanaged APIs, user interface, threads, synchronization Security Ø Ø Ø Authorized access to SQL Server data from user code via SQL Server authorization model Authorized access to system resources from user code via runtime code permissions Administrators control permissions given to assemblies Three Code Permission Sets l SAFE Ø Execute & data access permission Ø No access to resources outside SQL Server No unmanaged calls Must be verifiable Ø Ø l EXTERNAL_ACCESS Ø Ø Ø Ø l SAFESQL + access to external resources (Net, File permissions) Requires EXTERNAL ACCESS permission to create SQL Server will impersonate the caller Must be verifiable UNRESTRICTED Ø Ø No controls: Can call unmanged code, can be un-verifiable unOnly Administrators can create PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 4
- 5. Hosting .NET Runtime l Scalability As many concurrent users as, as fast as TransactTransact-SQL Ø § Integrated SQL Server and runtime threads § Collaboration between SQL Server and GC SQL Server becomes OS to the .NET runtime § l Speed Efficient data access in process Compiled user code, not interpreted as TransactTransact-SQL Fast transitions in/out of runtime Ø Ø Ø Speed: Functions .NET function vs. Transact-SQL inline 600 .NET function vs. Transact-SQL function 400 200 1000000 0 1 3 5 7 9 Query time (ms) Query time (ms) 800 100000 10000 11 1 3 15 17 19 21 1000 Integer ops per func call 100 .NET func 23 25 27 29 10 TSQL inline 1 100 1000 10000 Integer ops per call .NET functions approximating speed of TransactTransact.NET func TSQL func SQL inline expressions .NET framework functions much faster than TransactTransact-SQL functions for complex expressions PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 5
- 6. Outline l l Motivation Basic Infrastructure Ø Ø Ø l SQL features Ø Ø Ø l Hosting overview Data access inside process: ADO.NET SQL types Server assemblies Functions, procedures, triggers Types and aggregates Summary ADO .NET Data Access Controls, Designers, etc XSL/T, X -Path, XValidation, etc XmlDataXmlDataDocument XmlReader XmlText- XmlNodeXmlText- XmlNode Reader Reader DataSet Sync SQL Server Managed Managed Managed Provider Provider Provider XmlReader XmlText- XmlNodeXmlText- XmlNode Reader Reader PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 6
- 7. Data Access Inside SQL using System.Data.SqlServer; System.Data.SqlServer; using System.Data.SqlTypes; System.Data.SqlTypes; public class ShippingCosts { public static SqlMoney FreightByShipper( string ship ) { FreightByShipper( SqlCommand cmd = SqlContext.GetCommand( ); SqlContext.GetCommand( cmd.CommandText = "select sum(o.freight) as freight " + "from orders o join shippers s on o.shipvia = s.shipperid " + "where s.companyname = @CompanyName " ; @CompanyName SqlParameter param = cmd.Parameters.Add("@CompanyName", cmd.Parameters.Add("@CompanyName", SqlDbType.NVarChar, SqlDbType.NVarChar, COMPANY_NAME_COL_LENGTH); param.Value = ship; ship; SqlMoney amount = cmd.ExecuteScalar( ); cmd.ExecuteScalar( return amount; } } SQL Types l l l Reduce impedance mismatch between programming language and data Consistent expression evaluation in midmid- and server-tier programming serverSQL Types library Ø Ø Managed classes: System.Data.SqlTypes Provide SQL semantics § § Nullability, threeNullability , three-valued logic Precision and scale in operations PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 7
- 8. SQL Types Example Tax function using SQL types l using System; using System.Data.SQLTypes ; public class myFinances { public static SQLDouble tax( SQLDouble sal ) { if ( sal < 50000.0 ) return sal * 0.15; 0.15; if ( sal >= 50000.0 && sal <= 90000.0 ) return sal * 0.23 else return sal * 0.35; 0.35; } } SQLDouble makes function NULL-aware NULL- Outline l l Motivation Basic Infrastructure Ø Ø Ø l SQL features Ø Ø Ø l Hosting overview Data access inside process: ADO.NET SQL types Server assemblies Functions, procedures, triggers Types and aggregates Summary PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 8
- 9. SQL Features Assemblies Functions Procedures Triggers Types l l l l l Creating An Assembly CREATE ASSEMBLY geom FROM ‘m1typesgeometry.dll’ ‘ m1types WITH PERMISSION_SET = SAFE WITH AUTOREGISTER DROP ASSEMBLY lib_geom l Assemblies stored in database Ø l Ø l Safe (default), external access, unrestricted Autoregister functions Ø l Backup, restore with data Code permissions assigned per assembly Using .NET custom attributes Assembly benefits Ø Ø SelfSelf-describing metadata: Types, file dependencies Unit of code deployment: Permissions, versioning PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 9
- 10. Altering An Assembly l l Cannot invalidate persistent data or indexes Implies Ø Ø l l No tables with columns of UDT from this assembly No indexes on functions of this assembly Force option allows ALTER even if persistent dependencies exist Packaging considerations Ø Place routines and types in different assemblies Creating A Function CREATE FUNCTION distance ( @x1 int, @y1 int, @x2 int, @y2 int ) RETURNS float int, int, int, EXTERNAL NAME ‘geom:CPoint.Distance’ ‘geom:CPoint.Distance’ DETERMINISTIC RETURNS NULL ON NULL INPUT DROP FUNCTION distance l Functions called from queries Ø Ø Ø l Can be scalar or table -valued Static class functions Deterministic functions Using a function in a query SELECT s.name FROM Supplier s WHERE dbo.distance ( s.x, s.y, @x, @y ) < 3 dbo.distance( PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 10
- 11. Creating A Procedure CREATE PROCEDURE check_inventory EXTERNAL NAME ‘events:CInventory.check_level’ ‘events:CInventory.check_level’ DROP PROCEDURE check_inventory l Procedures not called from queries Ø Ø Can contain SQL queries, updates or DDL Can return results directly to client Creating A Trigger CREATE TRIGGER supplier_event ON supplier AFTER INSERT, UPDATE EXTERNAL NAME ‘events:CNotif.Supp_Event’ ‘events:CNotif.Supp_Event’ DROP TRIGGER supplier_event l l Similar to procedures, plus Access to inserted, deleted tables PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 11
- 12. Creating A Type l Create or drop a type CREATE TYPE Point EXTERNAL NAME ‘geom:Point’ ‘geom:Point’ DROP TYPE Point l Using a type CREATE TABLE Supplier ( id INTEGER PRIMARY KEY, name VARCHAR(20), location Point ) l Using a type method in a query SELECT s.name FROM Supplier s WHERE s.location::distance( @point ) < 3 Query Optimization l Automatically gather function statistics Ø l Reorder of predicate evaluation Ø l Based on execution cost and statistics Function indexes Ø Ø l Value histograms, execution cost Speed up expensive functions Extends computed column indexes and index views Implied and residual predicates PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 12
- 13. Summary Richer server programming model l Ø Ø Ø Any .NET framework language Same mid - and server -tier data access: midserverADO. NET Same IDE, project model, debugging, tools SQL Server hosting of .NET runtime l Ø Safety, security, scalability, speed SQL Server .NET features l Ø Functions, stored procedures, triggers, types, aggregates Demos l l Sample code for function, stored procedure, and type Assemblies Ø l Functions and stored procedures Ø Ø l Safe versus external access Creation and execution Data access in-process via ADO .NET in- Types Ø Ø Ø Ø Ø Type contract Create type Create table with column of user-defined type userCreate index on column of user-defined type userInsert and query the table PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 13
- 14. © 2001 Microsoft Corporation. All rights reserved. PDC 2001 October 22-26, 2001 © 2001 Microsoft Corporation. All rights reserved. 14