COMPUTER SCIENCE AND ENGINEERING
SQL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Selects ALL fields from the table
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Selects only the first field in the table
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Selects the last field in the table
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Shows only the first row in the table
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Detailed explanation-1: -SELECT * finds all the columns currently in a table, so that changes in the structure of a table such as adding, removing, or renaming columns automatically modify the results of SELECT *. Listing the columns individually gives you more precise control over the results.
Detailed explanation-2: -The SELECT statement is used to select data from a database. The data returned is stored in a result table, called the result-set.
Detailed explanation-3: -An asterisk (” * “) can be used to specify that the query should return all columns of the queried tables. SELECT is the most complex statement in SQL, with optional keywords and clauses that include: The FROM clause, which indicates the table(s) to retrieve data from.
Detailed explanation-4: -It not only improves the performance but also makes your code more explicit. It also helps you create maintainable code, which will not break when you add new columns to your table, especially if you have views that refer to the original table.