Some Oracle Query Tricks

----Get factorial of number using query:
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with t as (select level as l from dual connect by level <=&value)
select EXP (SUM (LN (l))) MULTIPLY from t


----Get ORACLE_HOME path using query:
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select substr(file_spec, 1, instr(file_spec, '\', -1, 2) -1) ORACLE_HOME from dba_libraries where library_name = 'DBMS_SUMADV_LIB';