text: SELECT ATAN(-2,2) from db_root;
  
  SELECT ATAN(NULL,2) from db_root;
  
  SELECT ATAN(-2,NULL) from db_root;
  
  SELECT ATAN('-2',2) from db_root;
  
  SELECT ATAN('a',2) from db_root;
  
  select atan(123456789012345.12345,2) from db_root;
  
  SELECT ATAN2(PI(),0) from db_root;
  
  SELECT ATAN2(3.14,0) from db_root;
  
  SELECT ATAN2(NULL,0) from db_root;
  
  SELECT ATAN2(PI(),NULL) from db_root;
  
  SELECT ATAN2('a',0) from db_root;
  
  select atan2(123456789012345.12345,2) from db_root;