SQLite – Java

安裝

在Java 程序中使用SQLite 之前，我們需要確保機器上已經有SQLite JDBC Driver 驅動程序和Java。可以查看Java 教程了解如何在計算機上安裝Java。現在，我們來看看如何在機器上安裝SQLite JDBC 驅動程序。

從sqlite-jdbc庫下載sqlite-jdbc-(VERSION).jar的最新版本。
在您的class路徑中添加下載的jar文件sqlite-jdbc-(VERSION).jar ，或者在-classpath選項中使用它，這將在後面的實例中進行講解。

在學習下面部分的知識之前，您必須對Java JDBC 概念有初步了解。如果您還未了解相關知識，那麼建議您可以先花半個小時學習下JDBC 教程相關知識，這將有助於您學習接下來講解的知識。

連接數據庫

下面的Java 程序顯示瞭如何連接到一個現有的數據庫。如果數據庫不存在，那麼它就會被創建，最後將返回一個數據庫對象。

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");
  }
}

現在，讓我們來編譯和運行上面的程序，在當前目錄中創建我們的數據庫test.db 。 您可以根據需要改變路徑。我們假設當前路徑下可用的JDBC驅動程序的版本是sqlite-jdbc-3.7.2.jar 。

$javac SQLiteJDBC.java
$java -classpath ".:sqlite-jdbc-3.7.2.jar" SQLiteJDBC
Open database successfully

如果您想要使用Windows 機器，可以按照下列所示編譯和運行您的代碼：

$javac SQLiteJDBC.java
$java -classpath ".;sqlite-jdbc-3.7.2.jar" SQLiteJDBC
Opened database successfully

創建表

下面的Java 程序將用於在先前創建的數據庫中創建一個表：

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");
  }
}

上述程序編譯和執行時，它會在test.db中創建COMPANY表，最終文件列表如下所示：

-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 代碼顯示瞭如何在上面創建的COMPANY 表中創建記錄：

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");
  }
}

上述程序編譯和執行時，它會在COMPANY 表中創建給定記錄，並會顯示以下兩行：

Opened database successfully
Records created successfully

SELECT 操作

下面的Java 程序顯示瞭如何從前面創建的COMPANY 表中獲取並顯示記錄：

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");
  }
}

上述程序編譯和執行時，它會產生以下結果：

Opened database successfully
ID = 1
NAME = Paul
AGE = 32
ADDRESS = California
SALARY = 20000.0

ID = 2
NAME = Allen
AGE = 25
ADDRESS = Texas
SALARY = 15000.0

ID = 3
NAME = Teddy
AGE = 23
ADDRESS = Norway
SALARY = 20000.0

ID = 4
NAME = Mark
AGE = 25
ADDRESS = Rich-Mond
SALARY = 65000.0

Operation done successfully

UPDATE 操作

下面的Java 代碼顯示瞭如何使用UPDATE 語句來更新任何記錄，然後從COMPANY 表中獲取並顯示更新的記錄：

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");
  }
}

上述程序編譯和執行時，它會產生以下結果：

Opened database successfully
ID = 1
NAME = Paul
AGE = 32
ADDRESS = California
SALARY = 25000.0

ID = 2
NAME = Allen
AGE = 25
ADDRESS = Texas
SALARY = 15000.0

ID = 3
NAME = Teddy
AGE = 23
ADDRESS = Norway
SALARY = 20000.0

ID = 4
NAME = Mark
AGE = 25
ADDRESS = Rich-Mond
SALARY = 65000.0

Operation done successfully

DELETE 操作

下面的Java 代碼顯示瞭如何使用DELETE 語句刪除任何記錄，然後從COMPANY 表中獲取並顯示剩餘的記錄：

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");
  }
}

上述程序編譯和執行時，它會產生以下結果：

Opened database successfully
ID = 1
NAME = Paul
AGE = 32
ADDRESS = California
SALARY = 25000.0

ID = 3
NAME = Teddy
AGE = 23
ADDRESS = Norway
SALARY = 20000.0

ID = 4
NAME = Mark
AGE = 25
ADDRESS = Rich-Mond
SALARY = 65000.0

Operation done successfully

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SQlite 教程

SQLite 高級教程

SQLite 接口

SQLite – Java

安裝

連接數據庫

創建表

INSERT 操作

SELECT 操作

UPDATE 操作

DELETE 操作