Question

Contents of the PUBLISHER table​ If a column named SAL_PCT is to be defined to ensure a value of 100 is input if a NULL value is provided when a new row is inserted, which column definition should be used?

a) DEFAULT 100
b) CHECK (SAL_PCT = 100)
c) CONSTRAINT SAL_PCT DEFAULT 100
d) CONSTRAINT SAL_PCT CHECK (SAL_PCT = 100)

Answer 1

The correct column definition to set a value of 100 when a NULL is inserted in the SAL_PCT column is 'CONSTRAINT SAL_PCT DEFAULT 100'.

Step-by-step explanation:

In the context of SQL table definitions, to ensure that a column named SAL_PCT is set to a value of 100 when a NULL value is provided upon insertion of a new row, the correct column definition to use is c) CONSTRAINT SAL_PCT DEFAULT 100. This SQL constraint will automatically insert a default value of 100 into the SAL_PCT column whenever a new row is created without specifying a value for this column. The CHECK constraint, as in option b) and option d), is used to restrict the range of values that can be inserted into a column, rather than setting a default value.