JDBC Tutorials - Herong's Tutorial Examples - v3.12, by Dr. Herong Yang
Inserting CLOB Values with setClob() Method
This section describes how to insert CLOB values with the PreparedStatement.setClob() method.
If you want to insert a CLOB column with a character string that comes from a java.sql.Clob object, you can directly set the value with PreparedStatement.setClob() method.
To test this, I wrote the following program to copy some records with CLOB values as new records back into the same table. During the copy process, the CLOB values are also modified with some Clob object methods - The first 32 characters are converted to upper case characters.
/* MySqlClobSetClob.java * Copyright (c) HerongYang.com. All Rights Reserved. */ import java.io.*; import java.sql.*; public class MySqlClobSetClob { public static void main(String [] args) { Connection con = null; try { com.mysql.cj.jdbc.MysqlDataSource ds = new com.mysql.cj.jdbc.MysqlDataSource(); ds.setServerName("localhost"); ds.setPortNumber(3306); ds.setDatabaseName("HerongDB"); ds.setUser("Herong"); ds.setPassword("TopSecret"); con = ds.getConnection(); // Deleting records for re-testing Statement sta = con.createStatement(); sta.executeUpdate( "DELETE FROM Article WHERE Subject LIKE 'Copy of %'"); // Creating a PreparedStatement for inserting new records PreparedStatement ps = con.prepareStatement( "INSERT INTO Article (Subject, Body) VALUES (?,?)"); // Looping though the first 3 records ResultSet res = sta.executeQuery( "SELECT * FROM Article ORDER BY ID"); int i = 0; while (res.next() && i<3) { i++; System.out.println("Copying record ID: "+res.getInt("ID")); String subject = res.getString("Subject"); Clob body = res.getClob("Body"); // Modifying the Clob object String chuck = body.getSubString(1,32); chuck = chuck.toUpperCase(); body.setString(1,chuck); // Inserting a new record with setClob() ps.setString(1, "Copy of "+subject); ps.setClob(2,body); ps.executeUpdate(); } ps.close(); res.close(); // Checking the new records res = sta.executeQuery( "SELECT * FROM Article WHERE Subject LIKE 'Copy of %'"); while (res.next()) { System.out.println("Record ID: "+res.getInt("ID")); System.out.println(" Subject = "+res.getString("Subject")); String body = res.getString("Body"); if (body.length() > 100) body = body.substring(0,100); System.out.println(" Body = "+body+"..."); } res.close(); sta.close(); con.close(); } catch (Exception e) { System.err.println("Exception: "+e.getMessage()); e.printStackTrace(); } } }
The program performed exactly as I expected:
herong> java -cp .:mysql-connector-java.jar MySqlClobSetClob.java Copying record ID: 1 Copying record ID: 2 Copying record ID: 5 Record ID: 6 Subject = Copy of Test on INSERT statement Body = A BLOB (BINARY LARGE OBJECT) IS a large chunk of data which is stored in a database.... Record ID: 7 Subject = Copy of Test of the setString() method Body = HE IS WONDERFUL AND STRANGE AND who knows how old he is, he thought. Never have I had such a strong ... Record ID: 8 Subject = Copy of Test of setCharacterStream() methods Body = /* MYSQLCLOBSETCHARACTERSTREAM.Java * Copyright (c) HerongYang.com. All Rights Reserved. */ ...
Table of Contents
JDBC (Java Database Connectivity) Introduction
Installing and Running Java DB - Derby
Derby (Java DB) JDBC DataSource Objects
Java DB (Derby) - DML Statements
Java DB (Derby) - ResultSet Objects of Queries
Java DB (Derby) - PreparedStatement
MySQL JDBC Driver (MySQL Connector/J)
MySQL - Reference Implementation of JdbcRowSet
MySQL - JBDC CallableStatement
►MySQL CLOB (Character Large Object) - TEXT
Overview of CLOB (Character Large Object)
Create Tables with CLOB Columns
Inserting CLOB Values with SQL INSERT Statements
Inserting CLOB Values with setString() Method
Inserting CLOB Values with setCharacterStream() Method
Retrieving CLOB Values with getString() Method
Retrieving CLOB Values with getCharacterStream() Method
Retrieving CLOB Values with getClob() Method
►Inserting CLOB Values with setClob() Method
MySQL BLOB (Binary Large Object) - BLOB
Oracle Express Edition Installation on Windows
Oracle - Reference Implementation of JdbcRowSet
Oracle - JBDC CallableStatement
Oracle CLOB (Character Large Object) - TEXT
Oracle BLOB (Binary Large Object) - BLOB
Microsoft SQL Server Express Edition
Microsoft JDBC Driver for SQL Server
Microsoft JDBC Driver - Query Statements and Result Sets
Microsoft JDBC Driver - DatabaseMetaData Object
Microsoft JDBC Driver - DDL Statements
Microsoft JDBC Driver - DML Statements
SQL Server - PreparedStatement
SQL Server CLOB (Character Large Object) - TEXT
SQL Server BLOB (Binary Large Object) - BLOB
JDBC-ODBC Bridge Driver - sun.jdbc.odbc.JdbcOdbcDriver
JDBC-ODBC Bridge Driver - Flat Text Files
JDBC-ODBC Bridge Driver - MS Access
JDBC-ODBC Bridge Driver - MS SQL Server
Summary of JDBC Drivers and Database Servers