Q21. A value which automatically appears in a column as soon as we enter the new record is called ____________________
Q22. Which constraint ensures that a column cannot have NULL values?
Q23. ___________________ statement is used to create a database and its tables.
Q24. DDL stands for _______________________
Q25. Write a command to create a database named 'stock' in MySQL.
Q26. ____________________ command that lists names of all the tables within a database.
Q27. Which of the following command is used to open the database that we want to use?
Q28. What is the degree of a table which has 'N' columns and 'M' tuples in a table?
Q29. What is the cardinality of a table which has 'N' columns and 'M' tuples in a table?
Q30. By default, each attribute can take NULL values except for the ____________________