Contenido del Curso
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
Deleting Rows
We can conditionally select and delete rows from a table using the DELETE
statement.
Following is the syntax of the DELETE
statement:
The DELETE
statement selects rows from table_name
based on a condition
and deletes them.
Example: Removing Graduated Students
Consider a table students
with the following columns name
, age
, grade
, score
, and graduation_year
.
We would like to delete all the rows from the table where the graduation_year
is less or equal to 2024
, since those students have already graduated and we no longer want to retain their data.
This can be done using the following query:
Demonstration:
¿Todo estuvo claro?
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Sección 5. Capítulo 5