Cubrid Study notes LOBs type data

• Blob:binary Large Object
• Clob:character Large Object
• A binary one character type

Binary Read

Cubridcommand cmd = new Cubridcommand (SQL, conn);D bdatareader reader = cmd. ExecuteReader (); while (reader. Read ()) {    Cubridblob bimage = (cubridblob) reader[0];    byte[] bytes = new byte[(int) bimage.bloblength];    bytes = Bimage.getbytes (1, (int) bimage.bloblength);    //...}


Update  CLOB type

String sql = "UPDATE t SET C =?"; Cubridcommand cmd = new Cubridcommand (SQL, conn); Cubridclob Clob = new CUBRIDCLOB (conn);//use the ConnectionString for testingstr = "SERVER=LOCALHOST;DATABASE=DEMODB; Port=33000;user=public;password= "clob.setstring (1, str); Cubridparameter param = new Cubridparameter ();p Aram. ParameterName = "?"; Param. Cubriddatatype = Cubriddatatype.cci_u_type_clob;param. Value = Clob;cmd. Parameters.Add (param); cmd. ExecuteNonQuery ();

Let's take a look at a complete example.

Using Cubrid. Data.cubridclient;using system.diagnostics;using system;using system.io;using system.data.common;namespace            Lobexample{class Program {private static void ExecuteSQL (String sql, Cubridconnection conn) { using (cubridcommand cmd = new Cubridcommand (SQL, conn)) {cmd.            ExecuteNonQuery ();  }} private static void Createtesttablelob (Cubridconnection conn) {ExecuteSQL ("drop table            if exists T ", Conn);        ExecuteSQL ("CREATE TABLE T (b BLOB, C CLOB)", conn); } private static void Cleanuptesttablelob (Cubridconnection conn) {ExecuteSQL ("drop table if Exis        TS T ", conn); } static void Main (string[] args) {Cubridconnectionstringbuilder sb = new cubridconnectionstring            Builder ("localhost", "Demodb", "Public", "", "33000"); using (cubridconnection conn = new Cubridconnection (sb.)           GetConnectionString ())) {Conn.                Open ();                CREATETESTTABLELOB (conn);                String sql = "INSERT into t (c) VALUES (?)";                Cubridcommand cmd = new Cubridcommand (SQL, conn);                Cubridclob Clob = new CUBRIDCLOB (conn); String str = conn.                ConnectionString;                StreamReader r = new StreamReader ("test.txt");                String writestring = R.readtoend ();                R.close ();                Clob.setstring (1, writestring);                Cubridparameter param = new Cubridparameter (); Param.                ParameterName = "?"; Param.                Cubriddatatype = Cubriddatatype.cci_u_type_clob; Param.                Value = Clob; Cmd.                Parameters.Add (param); Cmd.                ExecuteNonQuery (); Cmd.                Close ();                String sql2 = "Select C from T"; using (Cubridcommand cmd2 = new Cubridcommand (SQL2, conn)) {DbDataReader reader = cmd2. ExecutereaDer (); while (reader.                        Read ()) {Cubridclob cImage = (cubridclob) reader[0];                        String str2 = cimage.getstring (1, (int) cimage.cloblength);                        StreamWriter w = new StreamWriter ("Testout.txt");                        W.write (STR2);                        W.close ();                        StreamReader r2 = new StreamReader ("Testout.txt"); String readstring = R2.                        ReadToEnd (); R2.                        Close (); Debug.Assert (writestring. Length = = ReadString.                        Length, "The inserted CLOB length is not valid!"); Debug.Assert (writestring.                    Equals (ReadString), "The CLOB is not inserted correctly!");                }} CLEANUPTESTTABLELOB (conn); Conn.            Close (); }        }    }}

Cubrid Study notes LOBs type data