2015.1.5 Write, read binary fields with Dbfactorysingleton and Oralce clob type fields read and write [unless internal parsing is required, do not use clob,clob speed more than 15 times times slower than blobs]

Write

FileStream fstr = File.openread (Tb_filepath. Text); The OpenRead function is used to open a read-only file, Openwrite writable

BinaryReader br = new BinaryReader (FSTR);

byte[] buffer = br. Readbytes ((int) fstr. Length);

String sql = string. Format ("INSERT into Nvduser_flt. File_source values (+, ', ',: cont, ' we ') ");

IDbConnection cnn = Dbfactorysingleton.getinstance (). Factory.getconnection ();

Cnn. Open ();

IDbCommand dbcom = Dbfactorysingleton.getinstance (). Factory.getcommand ();

Dbcom. Connection = CNN;

Dbcom.commandtext = SQL;

System.Data.IDataParameter mypara= dbfactorysingleton.getinstance (). Factory.getdataparameter ("cont", dbtype.binary);

Mypara. Value = buffer;

Dbcom. Parameters.Add (Mypara);

Dbcom. ExecuteNonQuery ();

Fstr. Close ();

Read

String sql = string. Format ("Select content from {0}.file_source where file_id={1}", Aislogical.dbuser,fid);

byte[] data = (byte[]) dbfactorysingleton.getinstance (). Factory.executescalar (SQL);

if (data! = NULL)

{

String EP = Application.executablepath;

EP = EP. Substring (0, Ep. LastIndexOf ("\ \") + 1);

Try

{

string[] FLs = Directory.GetFiles (EP, "Tmpsourcefile.*");

foreach (String fl in FLs)

File.delete (FL);

}

Catch {}

Try

{

String pf = EP + "Tmpsourcefile." +HZM;

FileStream stream = new FileStream (PF, filemode.createnew, FileAccess.Write);

BinaryWriter bw = new BinaryWriter (stream);

Bw. Write (data);

Bw. Close ();

Stream. Close ();

Thread.Sleep (100);

Process proc = new process ();

Proc. Startinfo.filename = PF;

Proc. Startinfo.arguments = "";

Proc. Start ();

}

Catch {}

}

CLOB, Blob is Oracle two special field type size limit are 4g,clob and blob is the difference is CLOB processing large string, and Blob is quite a sophomore binary file. Clob is similar to string comparisons in Oracle internal Dbms_lob, and is not described here.

Insert:

OracleParameter para = new OracleParameter ("cont", Oracletype.clob);

Para. Value = Xmlheader;

Cmd. Parameters.clear ();

Cmd. Parameters.Add (para);

Cmd.commandtext = "INSERT into Kmlview (name,content) VALUES (' Airport ',: cont)";

Cmd. ExecuteNonQuery ();

READ: No difference from reading a normal string

sql = string. Format ("Select content from {0}.kmlview where name= ' airport '", Aislogical.dbuser);

String data = Dbfactorysingleton.getinstance (). Factory.executescalar (SQL). ToString (). Trim ();

unless internal parsing is required, do not use CLOB , CLOB faster than BLOB Slow Speed the times more than

2015.1.5 Write, read binary fields with Dbfactorysingleton and Oralce clob type fields read and write [unless internal parsing is required, do not use clob,clob speed 15 times times slower than blobs]