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<p><b><span style="font-size:22pt">Explaination 112: </span></b></p>
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<span style="font-size:18pt">HAVING clause to specify which groups are to be displayed and thus further restrict the groups on the basis of aggregate information.The Oracle server performs the following steps when you use the Having clause <br>
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<span style="font-size:18pt">1. rows are grouped <br>
2. the group function is applied to the group 3. the group that match the criteria in the Having clause are displayed. <br>
WHERE clause cannot be use to restrict groups HAVING clause use to restrict groups <br>WHERE clause cannot be use when there is group functions. <br>
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<span style="font-size:18pt">Incorrect Answers : <br>
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<span style="font-size:18pt">A. Where clause cannot be use to restrict groups <br>
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<span style="font-size:18pt">D. When HAVING clause is use rows are grouped as well. <br>
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<span style="font-size:18pt">E. WHERE clause cannot be use when there is group function, instead HAVING is to be use. <br>
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<span style="font-size:18pt">F. There is no constraint to use HAVING clause in a subqueries. <br>
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<span style="font-size:18pt">Refer : Introduction to Oracle9i : SQL, Oracle University Student Guide, Aggregating Data <br>
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<span style="font-size:18pt">using Group Functions, p. 5-20
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