(1) Create an empty relational table to store information about the names of employers and the total number of positions offered by each employer. A name of relational table and the names of columns are up to you. Enforce the appropriate primary key and referential integrity constraints (if any). Next, load into the table information about the names of employers together with the total number of positions offered by each employer. If an employer offers no position then its name must be recorded with a number zero (0).

(2) Create a relational table that contains information about the names of all skills and the largest skill level possessed by an applicant and a number of applicant who possesses a skill at the highest level. Ignore the skills not possessed by any applicant. All data must be loaded into the table by the same SQL statement that creates the table. Enforce the appropriate primary key and referential integrity constraints (if any) after data is loaded.

(3) Add a column to a relational table POSITIONS to store information about the total number of skills needed by each advertised position. A name of the column is up to you. Assume that no more than 9 skills are needed for each position. Next, use a single UPDATE statement to set the values in the new column consistent with the present contents of the sample database.

(4) Use a single DELETE statement to remove from a relational table APPLIES all applications submitted by the applicants who do not have any skills. DELETE statement must be correct for any contents of the sample database.