SQLite - Java
安装
在 Java 程序中使用 SQLite 之前，我们需要确保机器上已经有 SQLite JDBC Driver 驱动程序和 Java。可以查看 Java 教程了解如何在计算机上安装 Java。现在，我们来看看如何在机器上安装 SQLite JDBC 驱动程序。
从 sqlite-jdbc 库下载 sqlite-jdbc-(VERSION).jar 的最新版本。
在您的 class 路径中添加下载的 jar 文件 sqlite-jdbc-(VERSION).jar，或者在 -classpath 选项中使用它，这将在后面的实例中进行讲解。
在学习下面部分的知识之前，您必须对 Java JDBC 概念有初步了解。如果您还未了解相关知识，那么建议您可以先花半个小时学习下 JDBC 教程相关知识，这将有助于您学习接下来讲解的知识。
连接数据库
下面的 Java 程序显示了如何连接到一个现有的数据库。如果数据库不存在，那么它就会被创建，最后将返回一个数据库对象。
import java.sql.*;public class SQLiteJDBC{ public static void main( String args[] ) { Connection c = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Opened database successfully"); }}现在，让我们来编译和运行上面的程序，在当前目录中创建我们的数据库 test.db。您可以根据需要改变路径。我们假设当前路径下可用的 JDBC 驱动程序的版本是 sqlite-jdbc-3.7.2.jar。
$javac SQLiteJDBC.java$java -classpath ".:sqlite-jdbc-3.7.2.jar" SQLiteJDBCOpen database successfully
如果您想要使用 Windows 机器，可以按照下列所示编译和运行您的代码：
$javac SQLiteJDBC.java$java -classpath ".;sqlite-jdbc-3.7.2.jar" SQLiteJDBCOpened database successfully
创建表
下面的 Java 程序将用于在先前创建的数据库中创建一个表：
import java.sql.*;public class SQLiteJDBC{ public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "CREATE TABLE COMPANY " + "(ID INT PRIMARY KEY NOT NULL," + " NAME TEXT NOT NULL, " + " AGE INT NOT NULL, " + " ADDRESS CHAR(50), " + " SALARY REAL)"; stmt.executeUpdate(sql); stmt.close(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Table created successfully"); }}上述程序编译和执行时，它会在 test.db 中创建 COMPANY 表，最终文件列表如下所示：
-rw-r--r--. 1 root root 3201128 Jan 22 19:04 sqlite-jdbc-3.7.2.jar-rw-r--r--. 1 root root 1506 May 8 05:43 SQLiteJDBC.class-rw-r--r--. 1 root root 832 May 8 05:42 SQLiteJDBC.java-rw-r--r--. 1 root root 3072 May 8 05:43 test.db
INSERT 操作
下面的 Java 代码显示了如何在上面创建的 COMPANY 表中创建记录：
import java.sql.*;public class SQLiteJDBC{ public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (1, 'Paul', 32, 'California', 20000.00 );"; stmt.executeUpdate(sql); sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (2, 'Allen', 25, 'Texas', 15000.00 );"; stmt.executeUpdate(sql); sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );"; stmt.executeUpdate(sql); sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );"; stmt.executeUpdate(sql); stmt.close(); c.commit(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Records created successfully"); }}上述程序编译和执行时，它会在 COMPANY 表中创建给定记录，并会显示以下两行：
Opened database successfullyRecords created successfully
SELECT 操作
下面的 Java 程序显示了如何从前面创建的 COMPANY 表中获取并显示记录：
import java.sql.*;public class SQLiteJDBC{ public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" ); while ( rs.next() ) { int id = rs.getInt("id"); String name = rs.getString("name"); int age = rs.getInt("age"); String address = rs.getString("address"); float salary = rs.getFloat("salary"); System.out.println( "ID = " + id ); System.out.println( "NAME = " + name ); System.out.println( "AGE = " + age ); System.out.println( "ADDRESS = " + address ); System.out.println( "SALARY = " + salary ); System.out.println(); } rs.close(); stmt.close(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Operation done successfully"); }}上述程序编译和执行时，它会产生以下结果：
Opened database successfullyID = 1NAME = PaulAGE = 32ADDRESS = CaliforniaSALARY = 20000.0ID = 2NAME = AllenAGE = 25ADDRESS = TexasSALARY = 15000.0ID = 3NAME = TeddyAGE = 23ADDRESS = NorwaySALARY = 20000.0ID = 4NAME = MarkAGE = 25ADDRESS = Rich-MondSALARY = 65000.0Operation done successfully
UPDATE 操作
下面的 Java 代码显示了如何使用 UPDATE 语句来更新任何记录，然后从 COMPANY 表中获取并显示更新的记录：
import java.sql.*;public class SQLiteJDBC{ public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1;"; stmt.executeUpdate(sql); c.commit(); ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" ); while ( rs.next() ) { int id = rs.getInt("id"); String name = rs.getString("name"); int age = rs.getInt("age"); String address = rs.getString("address"); float salary = rs.getFloat("salary"); System.out.println( "ID = " + id ); System.out.println( "NAME = " + name ); System.out.println( "AGE = " + age ); System.out.println( "ADDRESS = " + address ); System.out.println( "SALARY = " + salary ); System.out.println(); } rs.close(); stmt.close(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Operation done successfully"); }}上述程序编译和执行时，它会产生以下结果：
Opened database successfullyID = 1NAME = PaulAGE = 32ADDRESS = CaliforniaSALARY = 25000.0ID = 2NAME = AllenAGE = 25ADDRESS = TexasSALARY = 15000.0ID = 3NAME = TeddyAGE = 23ADDRESS = NorwaySALARY = 20000.0ID = 4NAME = MarkAGE = 25ADDRESS = Rich-MondSALARY = 65000.0Operation done successfully
DELETE 操作
下面的 Java 代码显示了如何使用 DELETE 语句删除任何记录，然后从 COMPANY 表中获取并显示剩余的记录：
import java.sql.*;public class SQLiteJDBC{ public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "DELETE from COMPANY where ID=2;"; stmt.executeUpdate(sql); c.commit(); ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" ); while ( rs.next() ) { int id = rs.getInt("id"); String name = rs.getString("name"); int age = rs.getInt("age"); String address = rs.getString("address"); float salary = rs.getFloat("salary"); System.out.println( "ID = " + id ); System.out.println( "NAME = " + name ); System.out.println( "AGE = " + age ); System.out.println( "ADDRESS = " + address ); System.out.println( "SALARY = " + salary ); System.out.println(); } rs.close(); stmt.close(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Operation done successfully"); }}上述程序编译和执行时，它会产生以下结果：
Opened database successfullyID = 1NAME = PaulAGE = 32ADDRESS = CaliforniaSALARY = 25000.0ID = 3NAME = TeddyAGE = 23ADDRESS = NorwaySALARY = 20000.0ID = 4NAME = MarkAGE = 25ADDRESS = Rich-MondSALARY = 65000.0Operation done successfully