Use SQL statements to express the following operations: 1. Find the course number and course name of

This question requires 10 points.

You can understand the first half of this statement, that is, [ select, from student,sc where and'001'], this paragraph is to filter out the names and student numbers of students who have taken the '001' course, and the second half of the paragraph is [ and exists( select * from sc as sc 2 where sc and sc'002'] is to determine whether the student has also learned the '002' course, pay attention to the self-connection of the sc table, that is, [where sc] This is the key, it is precisely because of this condition, so the first half of the whole statement and the second half of the result are combined, if there is no such condition, it will become, what you call 'the return value is always equal to true'.

To put it simply, the first half is [students who have taken the '001' course], and the second half is [students who have studied the '002' course]; Among them, [where sc] is the key to connecting the two results, which is equivalent to joining the two results inside, so as to obtain the final result [students who have learned '001' and '002' at the same time].

Summary. select the course number, grade from student inner join choose course on student. Student ID = Course Selection. Student ID where name='Li Yong'

Try the SQL language to complete the following query: search the name of the student in the same department as Li Yong, the name of the elective course, and the course grade.

select the course number letter is slippery, and the results are like this from student inner join choose course on student. Student ID = Course Selection. Student ID where name='Li Yong'

OK29 and 30 OK.

Thank you. 30 Grant Update(Grade), select on table c to Liu Chen;

update courseset grade = c2where count=‘200215121’

Thank you. All right. Uh-huh.

1. First of all, in the open SQL, check which states and cities in the market database are from, as shown in the following figure.

2. Then check the complete information of the market database, as shown in the figure below.

3. Then check which countries the ** merchants come from in the market database (remove duplicate countries).

4. Then check the student number, name, gender, major and admission score in the STU database, and the results will be sorted from high to low according to the admission score field, and if the admission score is the same, it will be sorted in ascending order by major.

5. Then query the student number, name, gender and age of all students in the STU database.

6. Finally, query the course number, course name and credit hours of all courses in the STU database, and add 10 to the number of credit hours of all courses, and the query result shows "increased class hours", which is completed as shown in the figure below.

select student number, course number, grade from Table A ( select course number ,max(grade) as mcj from table A group by course number) b where Table A course number = bCourse number and Table AGrades =

select t1.Student ID, T1Course number, T1Grade from table t1

where t1.Grades =

select max(t2.Grades =

from table t2

where t2.Course number, T1Course number group by t2Course number).

select student number, course number, max (grade) from table.

group by Student ID, Course ID.

A subquery is a query nested within a select, insert, update, or delete statement, or within another subquery. A child query can return one or more rows of results to the parent query.

For example: select *, select a from b where from c

select * from b where id = (select max(id) from c)

A view can be thought of as a virtual table or a storage query. Data that can be accessed through a view is not stored in the database as a unique object. The database is stored with select statements.

Delete the record. drop to delete tables, views, stored procedures, triggers, functions, databases, and more.

clear, remove these two mssql do not.

Data query select

Data Manipulation (DML) Update, Delete, Insert

Data Definition (DDL): create, alter, drop

Data Control (DCL) Grant, Revoke

Only indexes can speed up the execution of query statements.

Table set word value where condition.

C, D are excluded first

grade is the grade, numeric type, and the value does not need to be put in quotation marks, so choose A

But in mssql, the b answer execution is also correct and will implicitly convert.

table joins, you need to join the condition = = first

sage in>=20 and cname in 'access' is clearly not written that way.

cname in( 'access') is fine.

So the answer is a

Add the alter table add

Modify the alter table alter

Delete the alter table table drop as above.