A SELECT statement can be used to perform these three functions:
1. Choose rows from a table.
2. Choose columns from a table
3. Bring together data that is stored in different tables by creating a link between them.
Which set of keywords describes these capabilities?()
A. difference, projection, join
B. selection, projection, join
C. selection, intersection, join
D. intersection, projection, join
E. difference, projection, product
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A. Constraints provide data independence.
B. Constraints make complex queries easy.
C. Constraints enforce rules at the view level.
D. Constraints enforce rules at the table level.
E. Constraints prevent the deletion of a table if there are dependencies.
F. Constraints prevent the deletion of an index if there are dependencies.
A. CREATE TABLE EMP9$# AS (empid number(2));
B. CREATE TABLE EMP*123 AS (empid number(2));
C. CREATE TABLE PACKAGE AS (packid number(2));
D. CREATE TABLE 1EMP_TEST AS (empid number(2));
A. TRIM
B. REPLACE
C. TRUNC
D. TO_DATE
E. MOD
F. CASE
A. A MERGE statement is used to merge the data of one table with data from another.
B. A MERGE statement replaces the data of one table with that of another.
C. A MERGE statement can be used to insert new rows into a table.
D. A MERGE statement can be used to update existing rows in a table.
Evaluate this SQL statement:
In the statement, which capabilities of a SELECT statement are performed?()
A. Selection, projection, join
B. Difference, projection, join
C. Selection, intersection, join
D. Intersection, projection, join
E. Difference, projection, product
A. The UNIQUE constraint does not permit a null value for the column.
B. A UNIQUE index gets created for columns with PRIMARY KEY and UNIQUE constraints.
C. The PRIMARY KEY and FOREIGN KEY constraints create a UNIQUE index.
D. The NOT NULL constraint ensures that null values are not permitted for the column.
A. It releases the storage space used by the table.
B. It does not release the storage space used by the table.
C. You can roll back the deletion of rows after the statement executes.
D. You can NOT roll back the deletion of rows after the statement executes.
E. An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.
F. You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table
You need to perform certain data manipulation operations through a view called EMP_DEPT_VU, which you previously created. You want to look at the definition of the view (the SELECT statement on which the view was create.)
How do you obtain the definition of the view?()
A. Use the DESCRIBE command in the EMP_DEPT VU view.
B. Use the DEFINE VIEW command on the EMP_DEPT VU view.
C. Use the DESCRIBE VIEW command on the EMP_DEPT VU view.
D. Query the USER_VIEWS data dictionary view to search for the EMP_DEPT_VU view.
E. Query the USER_SOURCE data dictionary view to search for the EMP_DEPT_VU view.
F. Query the USER_OBJECTS data dictionary view to search for the EMP_DEPT_VU view.
You need to design a student registration database that contains several tables storing academic information.
The STUDENTS table stores information about a student. The STUDENT_GRADES table stores information about the student's grades. Both of the tables have a column named STUDENT_ID. The STUDENT_ID column in the STUDENTS table is a primary key.
You need to create a foreign key on the STUDENT_ID column of the STUDENT_GRADES table that points to the STUDENT_ID column of the STUDENTS table. Which statement creates the foreign key?()
A. CREATE TABLE student_grades (student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk REFERENCES (student_id) FOREIGN KEY student (student_id));
B. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));
C. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT FOREIGN KEY (student_id) REFERENCES student (student_id));
D. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));
A. SELECT last_name FROM EMP WHERE last_name LIKE ‘_A%’;
B. SELECT last_name FROM EMP WHERE last name =’*A%’
C. SELECT last_name FROM EMP WHERE last name =’_A%’;
D. SELECT last_name FROM EMP WHERE last name LIKE ‘*A%’
最新试题
Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2 (25)LAST_NAME VARCHAR2 (25)HIRE_DATE DATEWhich UPDATE statement is valid? ()
Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2(25)LAST_NAME VARCHAR2(25)HIRE_DATE DATEWhich INSERT statement is valid? ()
The PRODUCTS table has these columns:PRODUCT_ID NUMBER(4)PRODUCT_NAME VARCHAR2(45)PRICE NUMBER(8,2)Evaluate this SQL statement:SELECT *FROM PRODUCTSORDER BY price, product _ name;What is true about the SQL statement? ()
Which one is a system privilege? ()
The user Alice wants to grant all users query privileges on her DEPT table. Which SQL statement accomplishes this? ()
User Mary has a view called EMP_DEPT_LOC_VU that was created based on the EMPLOYEES, DEPARTMENTS, and LOCATIONS tables. She has the privilege to create a public synonym, and would like to create a synonym for this view that can be used by all users of the database. Which SQL statement can Mary use to accomplish that task?()
Examine these statements:CREATE ROLE registrarGRANT UPDATE ON dtudent_grades TO registrar;GRANT registrar to user1, user2, user3;What does this set of SQL statements do? ()
Which is an iSQL*Plus command? ()
Which is a valid CREATE TABLE statement? ()
Which statement correctly describes SQL and /SQL*Plus? ()