Difference between revisions of "Running Total"

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Line 58: Line 58:
 
SELECT whn, description, amount,
 
SELECT whn, description, amount,
 
@accumulator:=@accumulator+amount RunningTotal
 
@accumulator:=@accumulator+amount RunningTotal
FROM transact</div>
+
  FROM transact</div>
 
<div class="ecomm e-oracle" style="display: none">In Oracle the following query also works:
 
<div class="ecomm e-oracle" style="display: none">In Oracle the following query also works:
 
SELECT whn, amount, SUM(amount) OVER (ORDER BY whn)
 
SELECT whn, amount, SUM(amount) OVER (ORDER BY whn)
FROM transact</div>
+
  FROM transact</div>
 
</div>
 
</div>
 
{{Hacks Ref}}
 
{{Hacks Ref}}

Revision as of 15:02, 2 August 2012

In this example you are shown how to get a running total in a set of results.

Table 1 shows the results without the running total and Table 2 shows what we get with the running total.

Table 1
whndescriptionamount
2006-11-01Wages50
2006-11-02Company Store-10
2006-11-03Company Store-10
2006-11-04Company Store-10
2006-11-05Company Store-10
2006-11-06Company Store-10
Table 2
whndescriptionamountbalance
2006-11-01Wages5050
2006-11-02Company Store-1040
2006-11-03Company Store-1030
2006-11-04Company Store-1020
2006-11-05Company Store-1010
2006-11-06Company Store-100
schema:scott
DROP TABLE transact
 CREATE TABLE transact(
  whn DATE,
  description VARCHAR(20),
  amount INTEGER );
INSERT INTO transact VALUES ('2006-11-01','Wages',50);
INSERT INTO transact VALUES ('2006-11-02','Company Store',-10);
INSERT INTO transact VALUES ('2006-11-03','Company Store',-10);
INSERT INTO transact VALUES ('2006-11-04','Company Store',-10);
INSERT INTO transact VALUES ('2006-11-05','Company Store',-10);
INSERT INTO transact VALUES ('2006-11-06','Company Store',-10);

To calculate a running total a table needs to be joined to itself, each version can be called table x and table y.

SELECT x.whn, x.description, x.amount, 
       SUM(y.amount) AS balance
  FROM transact x
  JOIN transact y ON (x.whn>=y.whn)
  GROUP BY x.whn, x.description, x.amount

Learn how to split the amount table into cshIN and cshOUT

SELECT w AS dte, d AS description, a, balance
  FROM
  (SELECT x.whn AS w, x.description AS d, 
          x.amount AS a, SUM(y.amount) AS balance
     FROM transact x
     JOIN transact y ON (x.whn>=y.whn)
     GROUP BY x.whn, x.description, x.amount) t
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