It has only two tables, BOOKS and MOVIES, which contain book and movie titles (respectively) and an ID number. Suppose we have a very simple database that stores information about books and movies. ![]() ![]() ![]() Operators like MINUS, UNION or INTERSECT are widely used in SQL queries. These records may be found in many different tables, so we need set operators such as union and intersection in SQL to merge them into one table or to find common elements.ĭuring such operations, we take two or more results from SELECT statements and create a new table with the collected data. making a report with the names of every customer served by every department of a large company). Let's say we want to present every aspect of some key data group in one results table (e.g. Of course, we can't expect that all necessary data will be stored in one table. ![]() SQL queries let us choose the most important bits from large amounts of information. In this article, we'll take a closer look at them. Ever heard terms such as union and intersection in SQL? They're examples of set operators, and they come in handy when you need to combine information from multiple tables or queries.
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June 2023
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