sqlserver--Data Retrieval (query)

Use MyDataBase1

--* Indicates that all columns are displayed

--The query statement does not add a where condition to indicate that all rows are queried

Select *from tblstudent

---Query only some of the columns in the table

Select Tsid,tsname,tsgender from Tblstudent

---query only part of the row (using the Where condition to filter a portion of the row display), depending on the condition

SELECT * FROM Tblstudent where tsclassid=5

--Aliases for columns in the query result set

Select TSID as student number, tsname as student name, Tsgender as gender from Tblstudent

--can also be arranged in this way

Select

TSID as student number,

Tsname as student name,

Tsgender as Sex

From Tblstudent

Select

TSID ' (student number) ',--can output spaces

Tsname student Name,--Cannot output space

Tsgender Sex

From Tblstudent

Select

Student number =tsid,

Student name =tsname,

Sex =tsgender

From Tblstudent

Select

Student number =tsid,

Student name =tsname,

Sex =tsgender,

Marriage no = ' no '

From Tblstudent

--Not that select must be used in conjunction with from, you can use select alone

Select

Current system time =getdate ()

Select

Monitor = ' Yan Meng ',

Class flower = ' TBD ',

Ban Cao = ' TBD ',

Teacher in charge = ' song ci '

--distinct keyword, for results that have been queried and then remove duplicates

SELECT DISTINCT * from Tblstudent

Select distinct tsname,tsgender,tsaddress from tblstudent

sqlserver--Data Retrieval (query)