SQL – Using Group functions Reporting Aggregate data using the Group functions SQL has numerous predefined aggregate functions that can be used to write queries to produce exactly this kind of information.The GROUP BY clause specifies how to group rows from a data table when aggregating information, while the HAVING clause filters out rows that […]
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SQL – Restricting and Sorting Data The essential capabilities of SELECT statement are Selection, Projection and Joining. Displaying specific columns from a table is known as a project operation. We will now focus on displaying specific rows of output. This is known as a select operation. Specific rows can be selected by adding a WHERE […]
SQL – Using Single-Row Functions Using Single row functions to customize output Oracle SQL supplies a rich library of in-built functions which can be employed for various tasks. The essential capabilities of a functions can be the case conversion of strings, in-string or substring operations, mathematical computations on numeric data, and date operations on date […]