what is data type -5?

Hi, ALL,

[code}
SQLSMALLINT columnNameLen, columnDataType, colummnDataDigits,
columnDataNullable;
SQLULEN columnDataSize;
/* columnData = new SQLWCHAR *[numCols];
columnDataLen = new SQLLEN [numCols];*/
auto columnName = new SQLWCHAR[50];
memset( columnName, '\0', 50 );
ret = SQLDescribeCol( stmt, 1, columnName, 256,
&columnNameLen, &columnDataType, &columnDataSize, &colummnDataDigits,
&columnDataNullable );
if( ret != SQL_SUCCESS && ret != SQL_SUCCESS_WITH_INFO )
{
GetErrorMessage( errorMsg, 1, stmt );
result = 1;
}
[/code]

After executing the code above the value of columnDataType is -5
and all standard SQL types are positive.

What does -5 correspond to?
Is it the same as 5 which is SQL_SMALLINT, according to sql.h?

Thank you.