Cover text SQL UDF

cover.sql

        -- UDF that covers, hides, obscures characters, either from the left or right.
        -- Parameters: P_INPUT - input text
        --             P_Char  - Replacement character
        --             P_Num   - number of characters to cover, if negative, then
        --                       characters in the text are replaced from the right.
        --                       If postive then characters are replaced from the left.                                   
        -- Returns - input text with characters replaced from the left or right.
        -- IBM i Db2
        Create or replace Function Cover  (     
        P_INPUT VARChar(1000), P_Char Char(1), P_NUM INT)                         
        Returns VARCHAR(1000)                        
        Language SQL                               
        Deterministic                              
        Reads SQL Data                             
        Called on NULL Input                       
        Disallow Parallel                          
        Begin                                      
          Declare v_output varchar(1000); 
          Declare v_length INT;
          set V_length =Length(trim(P_Input)); 
          If abs(P_NUM)>V_Length then
           set V_output = repeat(P_Char, V_Length);
          Elseif P_NUM<0 then set
           V_output = substr(trim(P_Input), 1, V_length-abs(P_Num)) concat repeat(P_Char, abs(P_Num));
          Else  set 
           V_output = repeat(P_Char, P_Num) concat substr(trim(P_Input), P_NUM+1, V_length-P_Num) ;
          End If; 
          Return V_output;
        End   ;