This article reprinted from: https: //www.cnblogs.com/yuzhonghua/p/7612594.html
sql server database commonly used commands
Create a database:
Command: create database database name;
Example: create database student;
Delete the database:
Command: drop database database name;
Example: drop database student;
New Form:
Command: create table table name
(Column name data type, column names 2 .....)
Example: create table student
(sname char(20),sid int)
Delete table:
Command: drop table table name
Example: drop table student
Modify table structure:
(Insert (new) column)
Command: alter table table name
add new column name Data type
Example: alter table student
add sage int
(Delete the column)
Command: alter table table name
drop column 列名
Example: alter table student
drop column sid
(Modified column type)
Command: alter table table name
alter column name data type column
Example: alter table student
alter column sid float (float)
(New constraint)
Command: alter table table name
alter column column names new data types
Example: alter table student
alter column PK_sid primary key (sid) (the new primary key constraint is a constraint type)
(Delete constraints)
Command: alter table table name
drop column names
Example: alter table student
drop PK_sid
Query table of contents:
Command: select the data to be queried column names
from table
where filter criteria (packet data can not be screened)
(Advanced Search) [group by the column name (packet)
having filters (only the data packets to filter)
Sort order by (the arrangement of the control data are the final output of the positive sequence: asc, flashback: desc)]
Example: select sid
from student
where sid=2
【group by sid
having sid=1
order by desc】
Inserting the data value in the table and column must correspond :()
Command: insert into table
(Column name, column name)
values
(Value, value)
Example: insert into table
(sname,sid,sage)
values
( 'John Doe', 12, 15)
Modifying the data values in the table:
Command: update from the table name
set new column name = value
示例：update from student
set sname = 'John Doe'
Query mode :( bulk insert multiple data)
Command: (Total number of values must be the same and columns) insert into table
select value, value, value union all
selevt value, value, value
Example: insert into table
select 'John Doe', 15, 18
select 'John Doe', 16, 19
view:
Command: create view view name
as
select Column
from table
Example: create view students
as
select sname
from student
