MSDN Documentation

Windows Data Access APIs

This section covers the various Application Programming Interfaces (APIs) provided by Windows for accessing and managing data. This includes technologies for interacting with databases, file systems, and structured data stores.

Core Data Access Technologies

Windows offers a robust set of APIs to facilitate data operations. The primary categories include:

• ODBC (Open Database Connectivity): A standard API for accessing database management systems (DBMS). It allows applications to query databases using SQL statements, regardless of the underlying database system.

  Key functions include:

  SQLAllocHandle, SQLConnect, SQLExecDirect, SQLFetch, SQLFreeHandle

• OLE DB (Object Linking and Embedding Database): A data access interface designed for accessing data from a variety of sources in a uniform manner, including relational and non-relational data stores. It is built upon COM (Component Object Model).

  Key interfaces include:

  • IDBInitialize
  • IOpenRowset
  • IRowset
  • ICommand
• ADO (ActiveX Data Objects): A higher-level abstraction layer over OLE DB, providing a simpler object model for developers to access data. ADO.NET in .NET provides a managed version.

  Key objects include:

  • Connection
  • Command
  • Recordset
  • Field

File System APIs

Direct interaction with the Windows file system is crucial for many applications. The following APIs provide low-level and high-level access:

• Win32 File I/O Functions: The fundamental set of functions for file operations, including creating, reading, writing, and deleting files.

  Examples:

  CreateFile, ReadFile, WriteFile, CloseHandle, GetFileSizeEx

• File Management Functions: APIs for manipulating file attributes, directories, and performing more complex file operations.

  Examples:

  CopyFile, MoveFile, DeleteFile, CreateDirectory, FindFirstFile

Structured Data and Serialization

APIs for handling structured data and serialization/deserialization are essential for data persistence and inter-process communication.

• Registry API: Allows applications to store and retrieve configuration settings and other application-specific data in the Windows Registry.

  Key functions:

  RegOpenKeyEx, RegQueryValueEx, RegSetValueEx, RegCloseKey

• COM Structured Storage: A compound file binary format that allows applications to store and manage structured data within a single file, similar to a mini-file system.
• JSON and XML Parsing Libraries: While not always exposed as direct Windows APIs, various libraries and COM components exist for parsing and manipulating JSON and XML data, which are common data interchange formats.