Database (database) is a complex and very difficult field to complete, because in addition to understanding the structure, computer system, to complete a database of database designers, there must be thinking. , ability to analyze and recognize good issues. The following test on database will be helpful to test your knowledge.
Question 1. For the board of banks (MANV, TENNV, LCB). Want to check if all employees' salaries in the case of a basic salary increase of 10%, which of the following statements would we use?
Select MANV, TENNV, LCB * .10 from NHANVIEN
Select MANV, TENNV, LCB + LCB * .01 from NHANVIEN
Select MANV, TENNV, LCB + LCB * .10 from NHANVIEN
Select MANV, TENNV, LCB + 10 from NHANVIEN
Question 2. To select all columns and list all rows from the VATTU table with LOAIVT attribute (number type) is 1, which of the following statements is most correct?
SELECT * FROM VATTU WHERE LOAIVT = 1
SELECT * FROM VATTU WHERE GroupID = "1"
SELECT LOAIVT FROM VATTU WHERE LOAIVT = 1
SELECT LOAIVT FROM VATTU WHERE LOAIVT = "1"
Question 3. Which statement is used to calculate the total number of lines in the NHANVIEN table?
Select rowcount from NHANVIEN
Select sum (*) from NHANVIEN
Select count (*) from NHANVIEN
Select count_rows from NHANVIEN
Question 4. Equally connecting relationships by attributes is:
Perform the Subject and selection
Perform the Subject and projection
Perform projection and division
Perform the Subject and division
Question 5. Delete is an operation
Delete an attribute or delete a group of attributes
Delete a set or delete a set of sets
Delete a relationship in the database
Delete a column or multiple columns
Question 6. Why does the primary key not allow NULL?
Difficult to determine the uniqueness of rows
Difficult to determine the uniqueness of columns
Difficult to connect tables
Foreign key is difficult to identify
Question 7. Please select the corresponding word / phrase to complete the following statement: From a given group of super keys, it is possible .
Specify a primary key in it
Cannot identify a primary key in it
Define a group of attributes
Determine any attribute
Question 8. The link between the two tables is based on:
Primary key and foreign key
Properties that match each other between tables
The intention of the database administrator
The intention to join tables into a table has more properties
Question 9. The main components in the combined entity model include:
Table numbers, entities and relationships
Entity, association and number table
Entity, relationship, binding
Binding entities, associations and number tables
Question 10. What are the steps in building a database?