数据库二进制数据流处理

数据流处理
1.从数据库读取数据二进制流创建文件
public static string LoadFile(string filePath, string fileName)
{
try
{
if(CreateFolder(System.Environment.CurrentDirectory + filePath))
{
if
(!System.IO.File.Exists(System.Environment.CurrentDirectory + filePath + @"\" + fileName))
{
//创建文件对象以创建文件的形式打开文件
System.IO.FileStream fs = new
System.IO.FileStream(System.Environment.CurrentDirectory + filePath + @"\" + fileName, System.IO.FileMode.Create);
byte[] Data = new byte[0];
object cell =
AppServer.YsServiceBaseClient.DN_YS_SelectDATACELL("YS", fileName);
Data = (byte[])cell;
//将数组的内容写进文件
fs.Write(Data, 0, Data.Length);
//关闭文件
fs.Close();
}
}
}
catch
{
}
//return System.IO.Path.GetFullPath(filePath + @"\" + fileName);
return System.Environment.CurrentDirectory + filePath + @"\" + fileName;
}
2.把文件以二进制流的方式写进数据库
public static void SaveFilecell()
{
OpenFileDialog openFileDialog = new OpenFileDialog();
//openFileDialog.InitialDirectory =
Environment.GetFolderPath(Environment.SpecialFolder.Personal);
openFileDialog.InitialDirectory =
System.Environment.CurrentDirectory + @"\data";
openFileDialog.Filter = "CELL文件(*.cll)|*.cll|XML文件(*.xml)|*.xml|所有文件(*.*)|*.*";
if (openFileDialog.ShowDialog() == DialogResult.OK)
{
string FileName = openFileDialog.FileName;
System.IO.FileInfo myFile = new
System.IO.FileInfo(FileName);
System.IO.FileStream fs = new
System.IO.FileStream(FileName, System.IO.FileMode.Open);
int length = (int)fs.Length;
byte[] fileData = new byte[length];
try
{
fs.Read(fileData, 0, length);
AppServer.YsServiceBaseClient.DN_YS_InsertDATACELL("YS", , fileData);
MessageBox.Show("文件保存成功", "系统信息", MessageBoxButtons.OK, rmation);
}
catch (Exception ex)
{
throw new Exception("文件保存失败，原因：" +
ex.Message);
}
finally
{
fs.Close();
}
}
}
}
3.数据流在数据库内部的使用
表结构
表数据
转移数据库数据时
Select @data=data from dbo.a.DN_GY_DA TA
INSERT INTO dbo.b.dn_gy_data(data) values @data
这种方法不正确
正确方法如下：
ALTER PROCEDURE [dbo].[P_DN_GY_SelectSJJB] (
@Module VARCHAR(20),--模块
@Where VARCHAR(1000)--条件
/*
EXEC P_DN_GY_SelectSJJB 'ZW','' */
)
AS
BEGIN
SET NOCOUNT ON
create table [#Temp]
(
[ID] INT IDENTITY(1,1)PRIMARY KEY,
[Module] VARCHAR(20)NULL,
[Number] VARCHAR(100)NULL,
[Data] varbinary(max)NULL
)
if @Where =''
begin
insert into#Temp(Module,Number,Data)select Module,Number,Data from DN_GY_DATA where Module = @Module
end
else
begin
exec('insert into #Temp(Module,Number,Data) select
Module,Number,Data from DN_GY_DATA where Module = @Module and '+@Where) end
declare @i int,@j int,@number varchar(100),@data varbinary(max) select @i=1,@j=count(1)from #temp
while @i<=@j
begin
select @number=number,@data=data from #temp where id=@i
print'insert into DN_GY_DATA(Module,Number,Data)
values('''+@Module+''','''+@number+''','
print @data
print')'
set @i=@i+1
end
drop table [#Temp]
SET NOCOUNT OFF
END。