Retrieving CLOB Values with getString() Method

This section describes how to retrieve CLOB values with the ResultSet.getString() method.

The simplest way to retrieve the character string value from a CLOB column is to use the getString() method on the ResultSet object. Here is short example program:

/* MySqlClobGetString.java
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
import java.io.*;
import java.sql.*;
public class MySqlClobGetString {
  public static void main(String [] args) {
    Connection con = null;
    try {
      com.mysql.jdbc.jdbc2.optional.MysqlDataSource ds 
        = new com.mysql.jdbc.jdbc2.optional.MysqlDataSource();
      ds.setServerName("localhost");
      ds.setPortNumber(3306);
      ds.setDatabaseName("HerongDB");
      ds.setUser("Herong");
      ds.setPassword("TopSecret");
      con = ds.getConnection();

// Retrieving CLOB value with getString()
      Statement sta = con.createStatement(); 
      ResultSet res = sta.executeQuery("SELECT * FROM Article"); 
      int i = 0;
      while (res.next() && i<3) {
        i++;
        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 output of the program confirms that CLOB values can be retrieved with getString() method on the ResultSet object:

C:\herong>\Progra~1\java\jdk1.8.0_45\bin\java 
   -cp .;\local\lib\mysql-connector-java-5.1.36-bin.jar 
   MySqlClobGetString

Record ID: 1
   Subject = Test on INSERT statement
   Body = A BLOB (Binary Large OBject) is a large chunk of data which 
is stored in a database....
Record ID: 2
   Subject = 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: 5
   Subject = Test of setCharacterStream() methods
   Body = /* MySqlClobSetCharacterStream.java
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
...

Last update: 2015.

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 Installing and Running Java DB - Derby

 Derby (Java DB) JDBC Driver

 Derby (Java DB) JDBC DataSource Objects

 Java DB (Derby) - DML Statements

 Java DB (Derby) - ResultSet Objects of Queries

 Java DB (Derby) - PreparedStatement

 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

 Oracle Express Edition Installation on Windows

 Oracle JDBC Drivers

 Oracle - Reference Implementation of JdbcRowSet

 Oracle - PreparedStatement

 Oracle - JBDC CallableStatement

 Oracle CLOB (Character Large Object) - TEXT

 Oracle BLOB (Binary Large Object) - BLOB

 Microsoft SQL Server 2005 Express Edition

 Microsoft JDBC Driver for SQL Server - sqljdbc42.jar

 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

 Additional Tutorial Notes to Be Added

 Outdated Tutorials

 References

 PDF Printing Version