With SQL, how can you return the number of not null records in the “Persons” table?

Related MCQs

• With SQL, how can you return all the records from a table named “Persons” sorted descending by “FirstName”?
• With SQL, how do you select all the records from a table named “Persons” where the value of the column “FirstName” ends with an “a”?
• Consider a hash table of size seven, with starting index zero, and a hash function (3x + 4)mod7. Assuming the hash table is initially empty, which of the following is the contents of the table when the sequence 1, 3, 8, 10 is inserted into the table using closed hashing? Note that ‘_’ denotes an empty location in the table.
• View the Exhibit and examine the structure of the EMPLOYEES and DEPARTMENTS tables. Which SET operator would you use in the blank space in the following SQL statement to list the departments where all the employees have managers? SELECT department_id FROM departments ____ SELECT department_id FROM employees WHERE manager_id IS NULL;
• Which SQL function is used to count the number of rows in a SQL query?
•                  dump, writes out SQL DDL statements and SQL insert statements to a file, which can then be reexecuted to re- create the database.
• ANSI-standard SQL allows the use of special operators in conjunction with the WHERE clause. A special operator used to check whether an attribute value is null is
• Which join refers to join records from the write table that have no matching key in the left table are include in the result set:
• What SQL command will allow you to change the table STUDENT to add the constraint named GradeCheck that states that the values of the Grade column must be greater than 0?
• View the Exhibit and examine the data in the EMPLOYEES tables. Evaluate the following SQL statement: SELECT employee_id, department_id FROM employees WHERE department_id= 50 ORDER BY department_id UNION SELECT employee_id, department_id FROM employees WHERE department_id= 90 UNION SELECT employee_id, department_id FROM employees WHERE department_id= 10; What would be the outcome of the above SQL statement?