Course Content
Introduction to SQL
Introduction to SQL
2. Filtering Data
The WHERE ClauseChallenge: Help a Reader Find Their Favorite GenreChallenge: Fetching Older BooksConditional Expressions: Comparison OperatorsChallenge: Avoid the Damaged BooksChallenge: Highlight New ArrivalsChallenge: Budget-Friendly BooksConditional Expressions: The AND OperatorChallenge: Find Specific Books for a ReaderChallenge: Defining RangesChallenge: Multiple ConditionsConditional Expressions: The OR OperatorChallenge: Matching Multiple OptionsChallenge: Excluding A RangeConditional Expressions: The NOT OperatorChallenge: Negating a Range
3. Sorting Data
Basic SortingChallenge: Sorting the Library CatalogueSorting by Multiple ColumnsChallenge: Further Sorting the CatalogueSorting after Filtering DataChallenge: Find the Cheapest BooksChallenge: Help a Customer Find a BookThe LIMIT KeywordChallenge: Select Books for the Collector's SectionChallenge: Affordable Books
4. Populating a Database
Creating a TableChallenge: Creating a new Books TableInserting Rows into a TableChallenge: Inserting DataChallenge: Inserting More DataInserting Multiple RowsChallenge: Inserting Bulk DataPrimary KeysThe SERIAL KeywordChallenge: Changing the Books StructureSpecifying Default ValuesChallenge: Further Improving the Books Table
5. Updating & Deleting Data
Basic Sorting
Note
The rows fetched by a
SELECT
statement are ordered by default based on the date and time of insertion, with the oldest inserted row at the top and the most recently inserted row at the bottom. In the upcoming sections, we will learn how to insert rows into tables.
Summary:
- We can sort the results of a
SELECT
statement by using anORDER BY
clause; - The syntax of the
ORDER BY
clause is:ORDER BY column_name [ASC|DESC]
; - The keywords
ASC
orDESC
can be optionally used to specify the sorting order; - Usage Example:
SELECT * FROM students ORDER BY age DESC
.
1. Which clause can be used for ordering the retrieved data?
2. What is the correct syntax for using the ORDER BY clause?
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Section 3. Chapter 1