Question

I have a SQL query in which I am passing sysdate to the query problem is that when there is no matching date in table with sysdate then it don’t shows the zero even if there is nvl applied
here is my query

select * from molasses
where trunc(trn_dte) = trunc(sysdate)

But it show data only when current date is present in table but I want to show zero if no data found in table.please help me to do this in oracle 10 g. Because some times the situation is like above and I have to display zero when no data found

Answer 1

This is weird and I wouldn’t use it, it’s more of a hack:

SELECT col1, col2, ..., colN              --- numeric columns
FROM molasses
WHERE trunc(trn_dte) = trunc(sysdate)

UNION ALL

SELECT 0, 0, ..., 0
FROM dual
WHERE NOT EXISTS
      ( SELECT *
        FROM molasses
         WHERE trunc(trn_dte) = trunc(sysdate)
      ) ;

One only wonders what the application/user will understand when there is exactly one row in the table and all the values are zero.

---

I think this would work, too:

SELECT m.col1, m.col2, ..., m.colN              --- numeric columns
FROM dual LEFT JOIN molasses m
  ON trunc(m.trn_dte) = trunc(sysdate) ;

and show Nulls instead of (the wanted) 0s. Using the COALESCE() function could easily fix that, as well.