Set the specified attribute value in the specified instance to indeterminate, i.e. the actual attribute value will be unset such that a following sdaiTestAttr and sdaiTestAttrBN operation on the same attribute in the same instance will return sdaiFALSE. The functions sdaiGetAttr , sdaiGetAttrBN , sdaiGetAttrs , and sdaiGetAttrsBN on the same attribute will fail until a new value is assigned to the actual attribute. When the actual attribute value is an aggregate, this aggregate and all child aggregates will be deleted by this operation.
All attributes in an instance will have the value indeterminate, i.e. unset until a value is assigned by one of the following operations: sdaiPutAttr , sdaiPutAttrBN , sdaiPutAttrs , sdaiPutAttrsBN , sdaiCreateAggr , sdaiCreateAggrBN .
This operation is only applicable to Explicit attributes in application instances.
The model that holds the actual instance must be open for write access before this operation can successfully be performed.
Related functions: sdaiUnsetAttr , sdaiTestAttr , sdaiTestAttrBN , sdaiGetAttr , sdaiGetAttrBN , sdaiGetAttrs , sdaiGetAttrsBN , sdaiPutAttr , sdaiPutAttrBN , sdaiPutAttrs , sdaiPutAttrsBN , sdaiCreateAggr , sdaiCreateAggrBN .
Header:
#include "sdai.h"
Prototype:
void sdaiUnsetAttrBN(SdaiAppinstance appinstance,
SdaiString attributeName);
Arguments:

appinstance	A numeric instanceID that uniquely identifies the application instance of interest in the EDMdatabase^. The instanceID is defined by a sdaiCreateInstance or a sdaiCreateInstanceBN function.
attributeName	Name of the attribute in the instance specified by the <instance> argument that will be assigned the value indeterminate, i.e. that will be unset. Attribute names are case insensitive. The attribute name must be qualified with the entity name when the attribute name is not unique within the actual instance.

Returns:
Void – use sdaiErrorQuery to check for error in operation.
Examples:
SdaiAppinstance anInst;
SdaiErrorCode errCode;
...
sdaiUnsetAttrBN(anInst, "Coordinates");
if (errCode = sdaiErrorQuery()) {
/* Error in operation */
printf("\nError: %s in sdaiUnsetAttrBN \n",
edmiGetErrorText(errCode));
goto error;
}
. . .