1、access: select top (10) * from table1 where 1=1 2、db2: select column from table where 1=1 fetch first 10 rows only 3、mysql: select * from table1 where 1=1 limit 10 4、sql server: 读取前10条:select top (10) * from table1 where 1=1 读取后10条:select top (10) * from...
1、aess：select top (10) * from table1 where 1=1 2、db2：select column from table where 1=1 fetch first 10 rows only 3、mysql：select * from table1 where 1=1 limit 10 4、sql server:读取前10条：select top (10) * from table1 where 1=1 读取后10条：select top (10)...
select top (10) * from table1 where 1=1 db2：select column from table where 1=1 fetch first 10 rows only mysql：select * from table1 where 1=1 limit 10 sql server:读取前10条：select top (10) * from table1 where 1=1 读取后10条：select top (10) * from table1 order...
access: select top (10) * from table1 where 1=1 db2: select column from table where 1=1 fetch first 10 rows only mysql: select * from table1 where 1=1 limit 10 sql server: 读取前10条:select top (10) * from table1 where 1=1 读取后10条:select top (10) * from table1 order ...
从SQL Server 2012开始,引入了FETCH FIRST…ROWS ONLY语句,它也可以用于查询指定行数。以下是使用FETCH语句查询指定行数的示例代码: SELECTcolumn1,column2FROMtable_nameORDERBYcolumn1FETCHFIRST10ROWSONLY; 1. 2. 3. 4. 上述示例中,我们查询了名为table_name的表中的所有数据,并按column1列进行排序。然后,我们...
10 //返回前10行记录，和limit10的结果一样，即limit0,n=limit n3、OracleOracle需要使用rownum。select * from table where rownum<=5; //返回前5条数据4、DB2select * from table fetch first 5 rows only; //返回前5条数据select * from (select 列名1，列名2，row_number() over() as ...
如果在SQL中没有子查询或关联查询,那么id列都将显示一个1。否则,内层的SELECT语句一般会顺序编号。 id列分为三种情况: 1)id相同 如下普通查询,没有子查询。 explain select f.* from film f,film_actor fa,actor a where f.film_id = fa.film_id and fa.actor_id = a.actor_id and a.first_name ...
//Replace your table and column names accordingly //This should give you first 10 rows var Result = ( from c in datacontext.YourTableName select new { c.ID}).Take(10); //For getting last 10 rows you can do orderby descending var Result = ( from c in datacontext.YourTableName...
不做列运算:SELECT id WHERE age + 1 = 10,任何对列的操作都将导致表扫描,它包括数据库教程函数、计算表达式等等,查询时要尽可能将操作移至等号右边; sql语句尽可能简单:一条sql只能在一个cpu运算;大语句拆小语句,减少锁时间;一条大sql可以堵死整个库; 不用SELECT *; OR改写成IN:OR的效率是n级别,IN的效...
USE AdventureWorks2022; GO CREATE VIEW EmployeeName AS SELECT h.BusinessEntityID, p.LastName, p.FirstName FROM HumanResources.Employee AS h JOIN Person.Person AS p ON h.BusinessEntityID = p.BusinessEntityID; GO 根据此视图,这两个 Transact-SQL 语句在基表上执行相同的操作且生成相同的结果:SQL...