SAP HANA: exception Handling

I think that the exception handling in SAP Hana is a bit "non-intuitive" (to be nice…). 

I invest a bit of time in order to understand how does it exactly works. 

I prepared a small tutorial and summerized here below. 

Theory: 

In java

 public class myClass() {  
      ...  
      public void myMethod() {  
           ...  
           try {  
                //code to be executed causing exception  
           }  
           catch(Exception e) {  
                //log the exception  
           }  
           ...  
      }  
      ...  
 }  

Equivalent in SQLScript

 CREATE PROCEDURE myproc AS  
 BEGIN  
      ...  
   DECLARE EXIT HANDLER FOR SQL_ERROR_CODE MY_SQL_ERROR_CODE  
   BEGIN  
           -- log the exception  
   END;  
      -- code to be executed causing exception  
 end;  

Practical example

copy and paste on SAP HANA Studio. First prepare something: 

 CREATE TABLE MYTAB (I INTEGER PRIMARY KEY);  
 drop PROCEDURE myproc;  

Then create this procedure: 

 CREATE PROCEDURE myproc AS  
 BEGIN  
      declare myvar int;  
   DECLARE EXIT HANDLER FOR SQL_ERROR_CODE 1299  
     BEGIN  
         write_debug_log('MARCO TEST',   
                                  'Handler of the NO_DATA_FOUND exception of the select below (after the following begin end block)',   
                                  'SQL_ERROR_CODE = ' || ::SQL_ERROR_CODE || '; SQL_ERROR_MESSAGE = ' || ::SQL_ERROR_MESSAGE);   
     END;  
           begin   
                declare my_test int;  
                --CASE GENERIC FOR ANY POSSIBLE EXCEPTION  
                  DECLARE EXIT HANDLER FOR SQLEXCEPTION  
                  begin   
                             write_debug_log('MARCO TEST',   
                                                 'separate handler for division by 0',   
                                                 'SQL_ERROR_CODE = ' || ::SQL_ERROR_CODE || '; SQL_ERROR_MESSAGE = ' || ::SQL_ERROR_MESSAGE);   
                end;  
                my_test := 1/0;  
           end;  
   SELECT I INTO myVar FROM MYTAB; --NO_DATA_FOUND exception  
   SELECT 'NeverReached_noContinueOnErrorSemantics' FROM DUMMY;  
 END;  

Please, notice that I am using my classing logging procedure.
Just substitute this procedure with any other suitable to your environment for logging...

Then let it run: 

 --execute the code and raise the exceptions  
 call myproc;  
 --check the situation in the log table  
 select * from log   
 order by id desc;  

Again, here is the code for accessing my log table...
Just use the one of your environment.