Which of the following is correct about NOT NULL constraint?
A. NOT NULL constraint demands a column not to accept NULL values.
B. NOT NULL constraint demands a field to always contains some value.
C. One cannot insert a new record with a NULL value, when NOT NULL constraint is specified.
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Which of the given statements are true?
P : Foreign key cannot have a null value.
Q : Primary key and foreign key can exist in same relation.
R : Foreign key relation is known as target relation.
Which of the following is used to add a new attribute (column) in the existing relation schema?
Which of the following SQL commands would you use to query data?
SQL provides many powerful functions to help you manipulate data.These built-in functions fall into which of these following categories.
What would be the output of the following SQL query?
SQL> select ltrim(' Harish') from dual;
Which of the following operations in DBMS is used to retrieve a combination of tuples in two relations based on a common field in both the relations?
Which of the following operations selects only some of the tuples in DBMS?