Oracle Apex ---oracle service instance xe failed message when install.

Solution : 1. Try to delete the service using the command prompt: 1. Click Start, type ‘cmd’ in the search field, and when ‘cmd’ shows up in the list of options, right click it and select ‘Run as Administrator’.2. At the Command Prompt window, type “sc delete OracleServiceXE” without the quotes and press Enter.3. Type “Exit” and press Enter. Hope it helps.  C:\> sc stop OracleServiceXE                      (to Stop service) C:\> sc delete OracleServiceXE    ...

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row_number(),rank(),dense_rank().

Row_Number() This function will assign a unique id to each row returned from the query. Consider the following query: DECLARE @Table TABLE (       Col_Value varchar(2) ) INSERT INTO @Table (Col_Value)       VALUES ('A'),('A'),('A'),('B'),('B'),('C'),('C'); SELECT       Col_Value,       ROW_NUMBER() OVER (ORDER BY Col_Value) AS 'RowID' FROM       @Table;    After executing it, we will get: Col_Value RowID A 1 A 2 A 3 B 4 B 5 C 6 C 7 As we notice, each and...

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PLSQL LOOP USE

declare counter number :=0; result number; begin loop counter := counter+1; result := 19*counter; dbms_output.put_line('19'||'*'||counter||'='||result); if  counter>=10 then  exit; end if; end loop; end; Same code  declare counter number :=0; result number; begin loop counter := counter+1; result := 19*counter; dbms_output.put_line('19'||'*'||counter||'='||result); EXIT WHEN counter>=10;  end loop; end; --while loop declare counter number :=1; result number; begin while counter<=10 loop result := 19*counter; dbms_output.put_line('19'||'*'||counter||'='||result); counter...

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