sqlallocenv-mapping.md

title	description	author	ms.author	ms.date	ms.service	ms.subservice	ms.topic	helpviewer_keywords
SQLAllocEnv Mapping	SQLAllocEnv Mapping	David-Engel	davidengel	01/19/2017	sql	connectivity	reference	SQLAllocEnv function [ODBC], mapping mapping deprecated functions [ODBC], SQLAllocEnv

SQLAllocEnv Mapping

When an application calls SQLAllocEnv through an ODBC 3.x driver, the call to SQLAllocEnv(phenv) is mapped to SQLAllocHandle as follows:

1. The Driver Manager allocates an environment handle and returns it to the application. The Driver Manager calls SQLSetEnvAttr to set the SQL_ATTR_ODBC_VERSION environment attribute to SQL_OV_ODBC2.

2. When the application establishes the first connection to a driver, the Driver Manager calls

   SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, OutputHandlePtr)  
   

   in the driver with OutputHandlePtr set to phenv.