SQL Server Data Access Components (SDAC) 是一组存取SQL Server数据库的非可视控件,今天在盒子上看到这个控件,发行版本居然都V4.3了,怎么以前没有听说过呢,据说这个比ADO效率要高很多,我还没试过,只是据说,今天装上了,已经是破解版,带源码的,先学习一下。


SQL Server Data Access Components Overview

SQL Server Data Access Components (SDAC) is a library of components that provides access to Microsoft SQL Server databases. SDAC connects to SQL Server directly through OLE DB, which is a native SQL Server interface. The SDAC library is designed to help programmers develop faster and cleaner SQL Server database applications.

SDAC is a complete replacement for standard SQL Server connectivity solutions and presents an efficient alternative to the Borland Database Engine for access to SQL Server.

Related Products

Advantages of SDAC Technology

SDAC is a direct connectivity database wrapper built specifically for the SQL Server server. SDAC offers wide coverage of the SQL Server feature set and emphasizes optimized data access strategies.

Wide Coverage of SQL Server Features
By providing access to the most advanced database functionality, SDAC allows developers to harness the full capabilities of the SQL Server and optimize their database applications. SDAC provides complete support of working with SQL Server 2005 Compact Edition, Service Broker technology, the IRowsetFastLoad interface, working with metadata information, and MARS.

    SDAC Palette

Optimized Code
The goal of SDAC is to enable developers to write efficient and flexible database applications. The SDAC library is implemented using advanced data access algorithms and optimization techniques. Classes and components undergo comprehensive performance tests and are designed to help you write high-performance, lightweight data access layers.

Compatibility with Other Connectivity Methods
The SDAC interface retains compatibility with standard VCL data access components like BDE. Existing BDE-based applications can be easily migrated to SDAC and enhanced to take advantage of SQL Server-specific features. Project migration can be automated with the BDE/ADO Migration Wizard.


How Does SDAC Work?

SDAC allows you to connect to SQL Server through OLE DB, which is the lowest documented SQL Server interface.

SDAC connects through OLE DB through a set of COM-based interfaces. SDAC is designed to be lightweight and consists of a minimal layer between your code and SQL Server databases.

In comparison, the Borland Database Engine (BDE) uses several layers to access SQL Server, and requires additional data access software to be installed on client machines.

The BDE data transfer protocol is shown below.

BDE Connection Protocol
BDE Connection Protocol

SDAC allows you to avoid using BDE and DBLibrary.

SDAC Connection Flow
SDAC Connection Flow


All editions of SDAC include the following basic components:

  • TMSConnection - lets you set up and control connections to SQL Server
  • TMSQuery - queries execution, operates record set, flexible way updating database tables
  • TMSTable - lets you retrieve and update data in a single table without writing SQL statements
  • TMSStoredProc - executes stored procedures and functions
  • TMSSQL - executes SQL statements and stored procedures, which do not return rowsets
  • TMSScript - executes sequences of SQL statements
  • TMSUpdateSQL - lets you tune update operations for a DataSet component
  • TMSDataSource - provides an interface between a SDAC dataset components and data-aware controls on a form
  • TMSSQLMonitor - allows to monitor dynamic SQL executing in SDAC based applications
  • TMSConnectDialog - allows you to build custom prompts for usernames, passwords, and servers
  • TVirtualTable - dataset stores data in memory
  • MSDataAdapter - .NET component, uses TDataSet as data source for retrieving and saving data to System.Data.DataSet

SDAC Professional Edition includes the following additional components:

  • TMSLoader - allows you to quickly load data into SQL Server databases
  • TMSDump - serves to store a database or its parts as a script and also to restore database from received script
  • TMSServiceBroker - lets you work with Service Broker technology to send and receive messages
  • TMSMetaData - allows to retrieve embracing metadata on specified SQL object
  • TMSChangeNotification - lets you react on different server side changes on-the-fly. Based on the Query Notifications mechanism of SQL Server 2005
  • TMSTransaction - lets you control distributed transactions via Microsoft Distributed Transaction Coordinator
  • TMSCompactConnection - lets you set up and control connections to SQL Server Compact Edition
  • TCRBatchMove - transfers data between all types of TDataSet descendants
Key Features

The following list describes the main features of SQL Server Data Access Components.

  • Direct access to server data. Does not require installation of other data provider layers (such as BDE and ODBC)
  • VCL, VCL.NET, and CLX versions of library available
  • Full support of the latest Microsoft SQL Server versions, including Express and Compact Editions
  • Support for all SQL Server data types
  • Disconnected Model with automatic connection control for working with data offline
  • Local Failover for detecting connection loss and implicitly reexecuting certain operations
  • All types of local sorting and filtering, including by calculated and lookup fields
  • Automatic data updating with TMSQuery, TMSTable, and TMSStoredProc components
  • Unicode support
  • Support for many SQL Server-specific features, such as MARS and bulk copy operations
  • Advanced script execution with TMSScript component
  • Support for using macros in SQL
  • Easy migration from BDE and ADO with Migration Wizard
  • Lets you use Professional Edition of Delphi and C++Builder to develop client/server applications
  • Includes annual SDAC Subscription with Priority Support
  • Licensed royalty-free per developer, per team, or per site

Last modification:August 16th, 2009 at 12:30 pm