Kursinhalt
SQL Tutorial for Beginners
SQL Tutorial for Beginners
SQL Aliases
Ususally in database tables and columns can have long names. When you work with multiple tables, you should write the name of the column with the name of the table to define the column, for example, users.user_id and messages.date_created. To avoid overtyping, in SQL we use Aliases. They allow us to give temporary names to column or tables.
For example, for our table:
SELECT album, singer as some_label FROM songs as t WHERE t.album = 'The Dark Side of the Moon' OR t.singer = 'Mushmellow'
Here you use table songs as t. In the console, instead of singer, your column has a label some_label. This example is not demonstrative enough, but in the next section we'll work with multiple tables, and temporary names may be useful.
Swipe to start coding
Find top-3 newest songs, their singers, and years, but use songs table as s. Make the column title displayed with the label name.
Lösung
Wechseln Sie zum Desktop, um in der realen Welt zu übenFahren Sie dort fort, wo Sie sind, indem Sie eine der folgenden Optionen verwendenDanke für Ihr Feedback!
SQL Aliases
Ususally in database tables and columns can have long names. When you work with multiple tables, you should write the name of the column with the name of the table to define the column, for example, users.user_id and messages.date_created. To avoid overtyping, in SQL we use Aliases. They allow us to give temporary names to column or tables.
For example, for our table:
SELECT album, singer as some_label FROM songs as t WHERE t.album = 'The Dark Side of the Moon' OR t.singer = 'Mushmellow'
Here you use table songs as t. In the console, instead of singer, your column has a label some_label. This example is not demonstrative enough, but in the next section we'll work with multiple tables, and temporary names may be useful.
Swipe to start coding
Find top-3 newest songs, their singers, and years, but use songs table as s. Make the column title displayed with the label name.
Lösung
Wechseln Sie zum Desktop, um in der realen Welt zu übenFahren Sie dort fort, wo Sie sind, indem Sie eine der folgenden Optionen verwendenDanke für Ihr Feedback!
Wechseln Sie zum Desktop, um in der realen Welt zu übenFahren Sie dort fort, wo Sie sind, indem Sie eine der folgenden Optionen verwenden