sql server的一些常用 sql 语句

1.  查询系统连接数

SELECT * FROM[Master].[dbo].[SYSPROCESSES] WHERE [DBID] IN ( SELECT    [DBID]FROM    [Master].[dbo].[SYSDATABASES]WHERE    NAME='fb_data')order by cpu desc外连接SELECT people.fb_id as fbid, people.name as name, people.sex as sex, language.name as language, people.home_town_name as home_town, people.current_city_name as current_city, school.degree_name as degree, school.school_name as school, people.about as about, work.work_name as work, 'https://www.facebook.com/' + cast(people.fb_id as varchar(30)) as visit_url  FROM [fb_data].[dbo].[fb_people] as people  LEFT OUTER JOIN [fb_data].[dbo].[fb_people_family] as family on family.people_object_id = people.object_id  LEFT OUTER JOIN [fb_data].[dbo].[fb_people_language] as language on language.people_object_id = people.object_id  LEFT OUTER JOIN [fb_data].[dbo].[fb_people_school] as school on school.people_object_id = people.object_id  LEFT OUTER JOIN [fb_data].[dbo].[fb_people_work] as work on work.people_object_id = people.object_id  where people.object_id in ('FB001ccbc8a42213aa8cb46669d2c6a4a76f', 'FB000931a25e263b1c3d21df79834eec9491')  多列的拼接    declare @area_str varchar(200)  set @area_str=''  select @area_str = @area_str + ',' + name  from [fb_data].[dbo].[fb_people_language]  where people_object_id = 'FB00dd0dde5c611ae521b58f488b366a906c'  select @area_str as re

需要修改数据库的时候可以修改where里边的东西。