JDBC for MySQL - Herong's Tutorial Examples - v3.12, by Herong Yang
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) 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.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(); // 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:
herong> java -cp .:mysql-connector-java.jar MySqlClobGetString.java 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) HerongYang.com. All Rights Reserved. */ ...
Table of Contents
JDBC (Java Database Connectivity) Introduction
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