SELECT MAX(gpa) FROM student_grades WHERE gpa IS NOT NULL;
SELECT (gpa) FROM student_grades GROUP BY semester_end WHERE gpa IS NOT NULL;
SELECT MAX(gpa) FROM student_grades WHERE gpa IS NOT NULL GROUP BY semester_end;
SELECT MAX(gpa) GROUP BY semester_end WHERE gpa IS NOT NULL FROM student_grades;
SELECT MAX(gpa) FROM student_grades GROUP BY semester_end WHERE gpa IS NOT NULL;
第1题：
A. ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id);
B. ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
C. ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
D. ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
E. ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
第2题：
A. Column definitions cannot be altered to add DEFAULT values.
B. A change to the DEFAULT value affects only subsequent insertions to the table.
C. Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.
D. All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
第3题：
The STUDENT_GRADES table has these columns:STUDENT_ID NUMBER(12)SEMESTER_END DATEGPA NUMBER(4,3)The registrar requested a report listing the students‘ grade point averages (GPA) sorted from highest grade point average to lowest.Which statement produces a report that displays the student ID and GPA in the sorted order requested by the registrar? （）
A. SELECT student_id, gpa FROM student_grades ORDER BY gpa ASC;
B. SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa ASC;
C. SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa;
D. SELECT student_id, gpa FROM student_grades ORDER BY gpa;
E. SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa DESC;
F. SELECT student_id, gpa FROM student_grades ORDER BY gpa DESC;
第4题：
In which of the following situations should correlation names be used?（）
第5题：
The STUDENT_GRADES table has these columns:The registrar has asked for a report on the average grade point average (GPA) for students enrolled during semesters that end in the year 2000. Which statement accomplish this?（）
A.
B.
C.
D.
E.
F.
第6题：
A.Each extra column in the copy with more columns must not have a default value
B.Columns that are common to both versions of the table must be defined in the same order on the master and the slave
C.The slave database cannot have more columns than the master. Only the master database can have more columns
D.Columns that are common to both versions of the table must come first in the table definition, before any additional columns are additional columns are defined on either server
E.The master database cannot have more columns than the slave. Only the slave deatbase can have more columns
第7题：
The STUDENT_GRADES table has these columns:The register has requested a report listing the students‘ grade point averages (GPA), sorted from highest grade point average to lowest within each semester, starting from the earliest date. Which statement accomplishes this?（）
A. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester_end DESC, gpa DESC;
B. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester_end ASC, gpa ASC;
C. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester_end, gpa DESC;
D. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY gpa DESC, semester_end DESC;
E. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY gpa DESC, semester_end ASC;
第8题：
A. ALTER TABLE students ADD PRIMARY KEY _ id;
B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);
C. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;
D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
E. ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
第9题：
A.A table referenced in the FROM clause has no indexed column.
B.The table referenced in the FROM clause has more than 200 columns.
C.Two or more tables in the FROM clause have identical column names.
D.The FROM clause contains two or more tables in the SELECT statement.
第10题：
You need to replicate a table from a master to a slave. The master and slave copies of the table will have different number of columns. Which two conditions must be true?（）