sql问题?问了许多人,都不知道?谁可以帮忙一下吗
源码小严 2010-08-22 01:21:25 -- =============================================
-- Create database on mulitple filegroups
-- =============================================
IF EXISTS (
SELECT *
FROM sys.databases
WHERE name = N'<database_name, sysname, sample_database>'
)
DROP DATABASE <database_name, sysname, sample_database>
GO
CREATE DATABASE <database_name, sysname, sample_database>
ON PRIMARY
(NAME = <logical_filename1, , sample_database_file1>,
FILENAME = N'<data_filename1, , C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Datasample_database_1.mdf>',
SIZE = 10MB,
MAXSIZE = 50MB,
FILEGROWTH = 10%),
( NAME = <logical_filename2, , sample_database_file2>,
FILENAME = N'<data_filename2, , C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Datasample_database_2.ndf>',
SIZE = 10MB,
MAXSIZE = 50MB,
FILEGROWTH = 10%),
FILEGROUP <filegroup_1, , sample_database_filegroup1>
( NAME = <logical_filename3, , sample_database_file3>,
FILENAME = N'<data_filename3, , C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Datasample_database_3.ndf>',
SIZE = 10MB,
MAXSIZE = 50MB,
FILEGROWTH = 10%),
( NAME = <logical_filename4, , sample_database_file4>,
FILENAME = N'<data_filename4, , C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Datasample_database_4.ndf>',
SIZE = 10MB,
MAXSIZE = 50MB,
FILEGROWTH = 10%),
FILEGROUP <filegroup2, , sample_database_group_2>
( NAME = <logical_filename5, , sample_database_file5>,
FILENAME = N'<data_filename5, , C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Datasample_database_5.ndf>',
SIZE = 10MB,
MAXSIZE = 50MB,
FILEGROWTH = 10%)
LOG ON
( NAME = <logical_log_filename1, , sample_database_log_file1>,
FILENAME = N'<log_filename1, , C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Datasample_database_1.ldf>',
SIZE = 10MB,
MAXSIZE = 50MB,
FILEGROWTH = 10%),
( NAME = <logical_log_filename2, , sample_database_log_file2>,
FILENAME = N'<log_filename2, , C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Datasample_database_2.ldf>',
SIZE = 5MB,
MAXSIZE = 25MB,
FILEGROWTH = 5MB)
GO
这些代码是来自于sqlserver模板中!可是感觉有特别多特别多的疑问?????比如说FROM sys.databases
WHERE name = N'<database_name, sysname, sample_database>这句话!其中from sys.databases来自于这个数据库,这个是一个什么数据库啊!为什么经常看到它加在创建数据库的前面啊!还有where name字段名后面怎么跟了个数据库名,sysname,saple_database,还有再比如CREATE DATABASE <database_name, sysname, sample_database> ,创建数据库后面怎么跟了几个数据库名啊!我试过了,不可以的!可是?这儿!等等!还有许多疑问???有谁可以帮忙解释一下吗?谢谢!可以帮忙把 段代码好好解释一下,可以吗?