Page 89 - DCAP402_DCAO204_DATABASE MANAGEMENT SYSTEM_MANAGING DATABASE

Database Management Systems/Managing Database

Notes of valid values to be defined for a field and verify field validation against that list
automatically, they allow serial number fields to be automatically assigned correct values,
and much more.

5.7 Keywords

Column Level Constraints: If the constraints are defined along with the column definition, it is
called as a column level constraint.

Foreign Key: Foreign keys represent relationships between tables.
Primary Key: A primary key is one or more columns in a table used to uniquely identify each
row in the table.

Table Level Constraints: If the data constraint attached to a specific cell in a table references the
contents of another cell in the table then the user will have to use table level constraints.

5.8 Self Assessment

Fill in the blanks:

1. ............................ ensure that changes made to the database by authorized users do not
result in a loss of data consistency.
2. Setting a ......................... is appropriate when the actual value is unknown.

3. A multicolumn primary key is called a ......................... primary key.
4. The ......................... of the default value should match the data type of the column.
5. By granting ......................... privileges to roles you can customize authorization for specific
groups of people.
6. ......................... refers to the subgroup of SQL statements that controls access to database
objects and data.

7. ......................... command is used for gives access privileges to users for database.
8. The exact syntax for ......................... requests depends on the language in which SQL is
embedded.

9. A series of ......................... is executed to make tuples of the result available to the program.
10. Embedded SQL expressions for database modification (update, insert, and delete)
......................... a result.

5.9 Review Questions

1. Distinguish between primary key constraints and foreign key constraints.
2. What do you mean by NOT NULL concept in table creation? Explain
3. Explain authorization concept of database in detail.

4. If I want to search name "Amit Kumar" present in the table which one created by you.
What is the query to display "Amit Kumar"? Explain.
5. Create table sales_order _details with primary key as s_order_no and product_no and
foreign key as s_order_no referencing column s_order_no in the sales order table.

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