comparing SybaseASESqlAstTranslator with SybaseSqlAstTranslator the first one adds those checks in renderComparison

if ( lhsNotNullPredicate ) {
	appendSql( " and " );
	lhs.accept( this );
	appendSql( " is not null" );
}
if ( rhsNotNullPredicate ) {
	appendSql( " and " );
	rhs.accept( this );
	appendSql( " is not null" );
}

lhsNotNullPredicate}}is true due to the {{isParameter check in boolean lhsNotNullPredicate = rhs instanceof Literal || this.isParameter(rhs);