simple question re: select statement

numberscub · #1 (**permalink**) 01-15-12, 20:47

I have experience with simple queries using MySQL but I am trying to understand a piece of code written for Oracle. In lines 2 and 3, are we basically creating two new fields and populating them with the text "Total"

Thanks!

SELECT a.var AS "Var"
, 'TOTAL' AS "Text"
, 'TOTAL' AS "Text2"
, a.var2
FROM database a
UNION ALL
.
.
.

anacedent · #2 (**permalink**) 01-15-12, 21:13

Code:

SQL> select sysdate , 'TOTAL' AS "Text" , 'TOTAL' AS "Text2"   from dual;

SYSDATE 	    Text  Text2
------------------- ----- -----
2012-01-15 18:12:18 TOTAL TOTAL

I am not sure what your question is.

r937 · #3 (**permalink**) 01-15-12, 23:58

Quote:

Originally Posted by numberscub

In lines 2 and 3, are we basically creating two new fields and populating them with the text "Total"

yes, that's right

numberscub · #4 (**permalink**) 01-16-12, 00:28

r937 -

Thanks very much.

Littlefoot · #5 (**permalink**) 01-16-12, 11:11

However, UNION (ALL) leads to another option: the first SELECT statement (i.e. the one you posted) might be a header. For example:

Code:

SQL> set head off
SQL>
SQL> select 'Max salary' as total, 'Max comm' as total
  2  from dual
  3  union all
  4  select to_char(max(sal), '999G990D00'), to_char(max(comm), '999G990D00')
  5  from emp
  6  /

Max salary  Max comm
   5,000.00    1,400.00

SQL>

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