Informática. Programación. Desarrollo web. Diseño gráfico. Redes.

Quizzes de desarrollo web

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This query retrieves the first 3 rows: SELECT * FROM employee LIMIT 3;

UNIQUE and NOT NULL are contraints.

This query is correct: SELECT column1 FROM table1 UNION SELECT column2 FROM table2;

There are different versions of the SQL language.

AVG() returns the average of a numeric column.