SQLAllocEnv (core level only)
SQLAllocEnv allocates memory for an environment handle and initializes the driver call level interface for application use.
An application must call SQLAllocEnv before it calls any other driver function.
A driver cannot return SQLSTATE values directly after the call to SQLAllocEnv because no valid handle exists with which to call SQLError.
Two levels of SQLAllocEnv functions exist, one
within the driver manager (if you are using one) and one within the
driver. The driver manager does not call the driver-level function
until the application calls SQLConnect, SQLBrowseConnect,
or SQLDriverConnect. If an error occurs in the
driver-level SQLAllocEnv function, the driver manager-level SQLConnect, SQLBrowseConnect,
or SQLDriverConnect function returns SQL_ERROR.
A subsequent call to SQLError with henv, SQL_NULL_HDBC,
and SQL_NULL_HSTMT returns SQLSTATE IM004 (the driver SQLAllocEnv function
failed), followed by one of the following errors from the driver:
- SQLSTATE S1000 (General error)
- The HCL
OneDB™ ODBC Driver SQLSTATE value, which ranges
from
S1000toS19ZZ.For example, SQLSTATE S1001 (Memory-allocation failure) indicates that the call from the driver manager to the driver-level SQLAllocEnv returned SQL_ERROR, and the henv from the driver manager was set to SQL_NULL_HENV.