COMPUTER SCIENCE AND ENGINEERING
SQL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Where
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Order by
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From
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Select
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Detailed explanation-1: -The WHERE clause is used to filter records. It is used to extract only those records that fulfill a specified condition.
Detailed explanation-2: -The FILTER clause is used to filter the input data to an aggregation function and is more flexible than the WHERE clause.
Detailed explanation-3: -All three queries return the exact same result regardless of whether the filter and join condition are placed in the ON clause or the WHERE clause. As far as performance goes, it makes no difference whether the filter condition is placed in the ON clause or the WHERE in PostgreSQL.
Detailed explanation-4: -You should use the WHERE clause to filter the records and fetching only the necessary records. The WHERE clause is not only used in the SELECT statement, but it is also used in the UPDATE, DELETE statement, etc., which we would examine in the subsequent chapters.
Detailed explanation-5: -SQL filters are text strings that you use to specify a subset of the data items in an internal or SQL database data type. For SQL database and internal data types, the filter is an SQL WHERE clause that provides a set of comparisons that must be true in order for a data item to be returned.