Difference between revisions of "Running Total"

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<table class="db_ref">
 
<table class="db_ref">
 
<caption>Table 2</caption>
 
<caption>Table 2</caption>
<tr><th align='center'>'''whn'''</th><th>'''description'''</th><th align='center'>'''amount'''</th></tr>
+
<tr><th align='center'>'''whn'''</th><th>'''description'''</th><th align='center'>'''amount'''</th><th>'''balance'''</th></tr>
<tr><td align='left'>2006-11-01</td><td align='left'>Wages</td><td align='left'>50</td></tr>
+
<tr><td align='left'>2006-11-01</td><td align='left'>Wages</td><td align='left'>50</td><td>50</td></tr>
<tr><td align='left'>2006-11-02</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
+
<tr><td align='left'>2006-11-02</td><td align='left'>Company Store</td><td align='left'>-10</td><td>40</td></tr>
<tr><td align='left'>2006-11-03</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
+
<tr><td align='left'>2006-11-03</td><td align='left'>Company Store</td><td align='left'>-10</td><td>30</td></tr>
<tr><td align='left'>2006-11-04</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
+
<tr><td align='left'>2006-11-04</td><td align='left'>Company Store</td><td align='left'>-10</td><td>20</td></tr>
<tr><td align='left'>2006-11-05</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
+
<tr><td align='left'>2006-11-05</td><td align='left'>Company Store</td><td align='left'>-10</td><td>10</td></tr>
<tr><td align='left'>2006-11-06</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
+
<tr><td align='left'>2006-11-06</td><td align='left'>Company Store</td><td align='left'>-10</td><td>0</td></tr>
 
</table>
 
</table>
 
</div>
 
</div>
Line 42: Line 42:
 
  SELECT x.whn, x.description, x.amount,  
 
  SELECT x.whn, x.description, x.amount,  
 
         SUM(y.amount) AS balance
 
         SUM(y.amount) AS balance
   FROM transact x JOIN transact y ON (x.whn>=y.whn)
+
   FROM transact x
 +
  JOIN transact y ON (x.whn>=y.whn)
 
   GROUP BY x.whn, x.description, x.amount
 
   GROUP BY x.whn, x.description, x.amount
<p>If you want the money IN and money OUT to be separate a <code>CASE</code> expression can be used.</p>
+
<p>[[Credit_debit |Learn how to split the amount table into cshIN and cshOUT]]</p>
 
</div>
 
</div>
 
<source lang='sql' class='def'>
 
<source lang='sql' class='def'>
SELECT w AS dte, d AS description,  
+
SELECT w AS dte, d AS description, a, balance
      CASE WHEN (a>=0) THEN a ELSE NULL END AS moneyIN,
+
      CASE WHEN (a<0) THEN a ELSE NULL END AS moneyOUT,
+
      balance
+
 
   FROM
 
   FROM
 
   (SELECT x.whn AS w, x.description AS d,  
 
   (SELECT x.whn AS w, x.description AS d,  
 
           x.amount AS a, SUM(y.amount) AS balance
 
           x.amount AS a, SUM(y.amount) AS balance
     FROM transact x JOIN transact y ON (x.whn>=y.whn)
+
     FROM transact x
 +
    JOIN transact y ON (x.whn>=y.whn)
 
     GROUP BY x.whn, x.description, x.amount) t</source>
 
     GROUP BY x.whn, x.description, x.amount) t</source>
 
<div class="ecomm e-mysql" style="display: none">In MySQL the following query also works:
 
<div class="ecomm e-mysql" style="display: none">In MySQL the following query also works:
 
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}}

Latest revision as of 16:08, 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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