Sqlsever Query Basic

Query statement:

SQL Sever query statement;

1. Query all fields:

SELECT * FROM UserInfo

2. Conditional screening

(such as querying the username in userinfo)

Select UserName from UserInfo

　　WHERE statement:

SELECT * from UserInfo where sex= ' man ' and major= ' computer ' (and/or)

Top statement: Top 5* ... order by ... desc (desc marked descending-not written is ascending ) Note (number plus *) Brder by

Select Top UserInfo from the Where major= ' computer ' ORDER BY age DESC

Max: Query for the maximum number of values ( such as the oldest in the age field of the query )

Select Max(age) from UserInfo

Minimum-----min avg Avg

Sum: Sum (as follows, query age sum)

Select SUM(age) from UserInfo

count: Quantity ( such as the number of students who have computer majors found in all data )

Select Count(*) from UserInfo where major= ' computer '

As : Give the queried field an individual name, convenient for later use ( such as the above query results named UserCount)

Select COUNT (*) as UserCount from UserInfo where major= ' computer '

GROUP BY: Query result grouping () having Count (*) >3 (where cannot be used at this time)

Select COUNT (*) as Groupcount,major from UserInfo group by Major have count (*) >3

Like: Fuzzy query

SELECT * from UserInfo where reaname like '% sheet% '

Sqlsever Query Basic