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CHAPTER 5 Constraints > Mastery Check - Pg. 142

Chapter 5: Constraints 115 Summary Database constraints provide you with the ability to restrict the behavior of DML statements at the column, row, and table levels. They also let you enforce external relationship constraints that restrict values from being added, changed, or removed from tables. This chapter has covered NOT NULL, UNIQUE, primary key, CHECK, and foreign key database constraints, and it provided an introduction to the role of database triggers in restricting or modifying the behavior of DML statements. You have also been exposed to the Oracle and MySQL database implementation differences between these constraints. Mastery Check The mastery check is a series of true or false and multiple choice questions that let you confirm how well you understand the material in the chapter. You may check the Appendix for answers to these questions. 1. True False A database constraint can determine whether a column is mandatory or optional. 2. True False A database constraint can determine whether a row is unique in a table. 3. True False A database constraint can only accept or reject values for a column based on boundary conditions.