连接sqlserver数据库
package jdbc; import java.sql.Connection; import java.sql.Driver; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class JdbcTest1 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub String className = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //加载jdbc驱动,Class.forName()加载 try { Class.forName(className );//////////////////////////11111111111111 } catch (ClassNotFoundException e) { e.printStackTrace(); } Driver driver = null; ///注册jdbc驱动,在DriverManager类中注册,registerDriver(Driver driver) try { driver = new com.microsoft.sqlserver.jdbc.SQLServerDriver();/////////////////////////////////// DriverManager.registerDriver(driver );//////////////////////////////////222222222222 } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } //3建立数据库连接Connection对象,由DriverManager建立连接对象,知道连接什么数据库、连接用户名和密码 Connection con = null; String url ="jdbc:sqlserver://localhost:1433;DatabaseName=db";//jdbc url,不同数据库的识别方法是不一样的。 String user ="sa"; String password ="123456"; try{ con = DriverManager.getConnection(url, user, password);////////////////////////////////////// }catch(Exception e){ e.printStackTrace(); } //PreparedStatement PreparedStatement pstmt = null; String sql = "select * from book where price <? and number > ?"; try { pstmt = con.prepareStatement(sql );//////////////////////////// } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { pstmt.setFloat(1, (float) 50.0); pstmt.setInt(2, 5); } catch (SQLException e) { e.printStackTrace(); } //借助于语句对象,执行数据库sql操作 ResultSet rs = null; try { rs = pstmt.executeQuery();//////////////////////////////////////// } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } ///处理数据库查询结果 try { while(rs.next()){ String isbn = rs.getString(1); String author = rs.getString("author"); Float price = rs.getFloat("price"); Integer number = rs.getInt("number"); System.out.println("isbn:"+isbn+"\nauthor:"+author+"\ntotal:"+price*number+"\n"); } } catch (SQLException e) { e.printStackTrace(); } ///关闭资源,与开启顺序相反 try{ if(rs!=null){ rs.close(); } if(pstmt!=null){ pstmt.close(); } if(con!=null){ con.close(); } }catch(SQLException e){ e.printStackTrace(); } } }
连接mysql数据库
package jdbc; import java.sql.Connection; import java.sql.Driver; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class JdbcTest { /**查询数据库表中的内容,并在控制台输出显示 * @param args */ public static void main(String[] args) { String className = "com.mysql.jdbc.Driver"; //加载jdbc驱动,Class.forName()加载 try { Class.forName(className );//////////////////////////11111111111111 } catch (ClassNotFoundException e) { e.printStackTrace(); } Driver driver = null; ///注册jdbc驱动,在DriverManager类中注册,registerDriver(Driver driver) try { driver = new com.mysql.jdbc.Driver();/////////////////////////////////// DriverManager.registerDriver(driver );//////////////////////////////////222222222222 } catch (SQLException e) // TODO Auto-generated catch block e.printStackTrace(); } //3建立数据库连接Connection对象,由DriverManager建立连接对象,知道连接什么数据库、连接用户名和密码 Connection con = null; String url ="jdbc:mysql://localhost:3306/db";//jdbc url,不同数据库的识别方法是不一样的。 String user ="root"; String password ="123456"; try{ con = DriverManager.getConnection(url, user, password);////////////////////////////////////// }catch(Exception e){ e.printStackTrace(); } ////4...准备操作数据库前的工作,借助于Statement或PreparedStatement来操作数据库,可以通过Connection对象得到语句对象 //Statement Statement stmt = null; try { stmt = con.createStatement();/////////////////////////// } catch (SQLException e) { e.printStackTrace(); } /**PreparedStatement PreparedStatement pstmt = null; String sql = "select * from book where price <? and number > ?"; try { pstmt = con.prepareStatement(sql );//////////////////////////// } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { pstmt.setFloat(1, (float) 50.0); pstmt.setInt(2, 5); } catch (SQLException e) { e.printStackTrace(); }**/ //借助于语句对象,执行数据库sql操作 String sql = "select * from book where price <50 and number>5"; ResultSet rs = null; try { rs = stmt.executeQuery(sql);//////////////////////////////////////// } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } ///处理数据库查询结果 try { while(rs.next()){ String isbn = rs.getString(1); String author = rs.getString("author"); Float price = rs.getFloat("price"); Integer number = rs.getInt("number"); System.out.println("isbn:"+isbn+"\nauthor:"+author+"\ntotal:"+price*number+"\n"); } } catch (SQLException e) { e.printStackTrace(); } ///关闭资源,与开启顺序相反 try{ if(rs!=null){ rs.close(); } if(stmt!=null){ stmt.close(); } if(con!=null){ con.close(); } }catch(SQLException e){ e.printStackTrace(); } } }