Question 1 A _ indicates an absent value that may exist but be unknown or that may not exist at all.
    a. Null value

    Question 2 A Boolean data type that can take values true, false, and__
    Unknown

    Question 3 A Delete command operates on __ relation.
    One

    Question 4 Aggregate functions are functions that take a _ as input and return a single value.
    b. Collection of values

    Question 5 An attribute A of datatype varchar(20) has the value ‘Avi’. The attribute B of datatype char(20) has value ‘Reed’.
    Here attribute A has spaces and attribute B has spaces.
    b. 3, 20

    Question 6 CREATE TABLE employee (id INTEGER,name VARCHAR(20),salary NOT NULL);
    INSERT INTO employee VALUES (1005,Rach,0);
    INSERT INTO employee VALUES (1007,Ross, );
    INSERT INTO employee VALUES (1002,Joey,335);
    Some of these insert statements will produce an error. Identify the statement.
    c. Insert into employee values (1007,Ross, );