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.

 * Copyright (c) All Rights Reserved.
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();
      con = ds.getConnection();

// Deleting records for re-testing
      Statement sta = con.createStatement();
        "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 ( && i<3) {
        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();

// Inserting a new record with setClob()
        ps.setString(1, "Copy of "+subject);

// Checking the new records
      res = sta.executeQuery(
        "SELECT * FROM Article WHERE Subject LIKE 'Copy of %'");
      while ( {
        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+"...");

    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());

The program performed exactly as I expected:

herong> java -cp .:mysql-connector-java.jar

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
 * Copyright (c) All Rights Reserved.

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 MySQL Installation on Windows

 MySQL JDBC Driver (MySQL Connector/J)

 MySQL - PreparedStatement

 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

 Using Connection Pool with JDBC

 Archived Tutorials


 Full Version in PDF/EPUB