sql取第一条记录
⑴ 如何取sql结果集的第一条记录
在SQL Server数据库中,使用top关键字:
SELECT TOP number|percent column_name(s) FROM table_name
在MySQL数据库中,使用LIMIT关键字:
SELECT column_name(s) FROM table_name LIMIT number
例子:SELECT * FROM Persons LIMIT 1
在Oracle数据库中,使用ROWNUM关键字:
SELECT column_name(s) FROM table_name WHERE ROWNUM <= number
例子:SELECT * FROM Persons WHERE ROWNUM <= 1
⑵ sql取出第一条数据
select top 1 col1,col2 from tblname where col3='111' order by col1 desc;
试一下
⑶ 如何用SQL SERVER取分组数据第一条
根据table1_id进行分组所得结果:
select * from (select a.id as a_id,a.name,a.time,a.content,b.id as b_id,b.user from table1 a inner join table2 b on a.id = b.table1_ID) new_tbl where b_id in (select min(id) from table2 group by table1_ID)
(3)sql取第一条记录扩展阅读:
注意事项
在SQL Server数据库中,使用top关键字:SELECT TOP number|percent column_name(s) FROM table_name
在MySQL数据库中,使用LIMIT关键字:SELECT column_name(s) FROM table_name LIMIT number
例子:SELECT * FROM Persons LIMIT 1
select bookName from book where price > 20 limit 1;
limit 1;
or
limit 0,1;
在Oracle数据库中,使用ROWNUM关键字:
SELECT column_name(s) FROM table_name WHERE ROWNUM <= number
例子:SELECT * FROM Persons WHERE ROWNUM <= 1
⑷ sql语句,根据关键字,取第一条数据
select No,Count,max(Time) as Time
from 表
group by No,Count
⑸ sql语句,选第一条数据
几个常用数据库的写法如下:
1、mssql数据库
selecttop1*fromtable
2、Oracle数据库
select*fromtablewhererownum<2
3、MySQL数据库:
select*fromtablelimit0,1
(这里keyword limit startid,rownum是这样的:表示从startid + 1行开始,一共查询rownum条记录。
⑹ sql根据某一个字段重复只取第一条数据
代码如下:
select * from tbl_DPImg where ID in (select min(ID) from tbl_DPImg group by DPID)
处理后结果为:
查找表中多余的重复记录,重复记录是根据单个字段(teamId)来判断
select * from team where teamId in (select teamId from team group by teamId having count(teamId) > 1)
删除表中多余的重复记录,重复记录是根据单个字段(teamId)来判断,只留有rowid最小的记录
delete from team where
teamName in(select teamName from team group by teamName having count(teamName) > 1)
and teamId not in (select min(teamId) from team group by teamName having count(teamName)>1)
(6)sql取第一条记录扩展阅读
数据记录筛选:
sql="select * from 数据表 where字段名=字段值 order by字段名[desc]"(按某个字段值降序排列。默认升序ASC)
sql="select * from 数据表 where字段名like '%字段值%' order by 字段名 [desc]"
sql="select top 10 * from 数据表 where字段名=字段值 order by 字段名 [desc]"
sql="select top 10 * from 数据表 order by 字段名 [desc]"
sql="select * from 数据表 where字段名in ('值1','值2','值3')"
sql="select * from 数据表 where字段名between 值1 and 值2"
⑺ SQL 怎么查询每个人的第一条数据
select
mid ,content
from(
SELECT
mid ,content,
rank() over(ORDER BY content) as rank1
FROM tb_record) a
where a.rank1=1
⑻ sql如何查询第一个数据
sql如何查询第一个数据的方法。
如下参考:
1.首先,双击“ManagementStudio”图标打开SQLServer。
⑼ 要取一个字段中按照排序后的第一条记录,SQL语句怎么写
如果支持first函数就用:
SELECT FIRST(column_name) FROM pers_customer ORDER BY column_name
不支持可以用:
select * from (select * from table_name order by column_name) where rownum = 1
⑽ 如何取sql中的第一条
select top1 col1,col2 from tblname where col3='111' order by col1 desc;