simpleselect.java

weblogic应用全实例

//声明本类包含在包examples.jdbc.mssqlserver4中
package examples.jdbc.mssqlserver4;
//声明本类要引入的其他包和类
import java.sql.*;
import java.util.Properties;

/**
 * 这个实例演示如何用JDBC查询数据和结果集。 
 */

public class simpleselect {
  
  public static void main(String argv[])
  {
  //声明连接，SQL语句和结果集变量
    java.sql.Connection conn        = null;
    java.sql.Statement stmt         = null;
    java.sql.ResultSet rs           = null;
    
    try {
    //声明属性变量
      Properties props = new Properties();
     //设置属性：用户名、密码、服务器
      props.put("user", "sa");
      props.put("password", "secret");
      props.put("server", "myHOST:1433");
	//加载数据库驱动程序
      Driver myDriver = 
          (Driver)Class.forName("weblogic.jdbc.mssqlserver4.Driver").newInstance();
      //创建连接
      conn = myDriver.connect("jdbc:weblogic:mssqlserver4", props);
    	//创建SQL语句对象
      stmt = conn.createStatement();
    	//执行SQL语句
      stmt.execute("select * from sysdatabases");
    //取得结果集
      rs = stmt.getResultSet();
    //打印结果
      while (rs.next()) {
        System.out.println(rs.getString("name") + " - " + 
                           rs.getString("dbid")  + " - " + 
                           rs.getString("crdate"));
      }
    //获得元数据对象
      ResultSetMetaData rsmd = rs.getMetaData();
    //获取并打印列数
      System.out.println("Number of Columns: " + rsmd.getColumnCount());
      //打印表结构信息
      for (int i = 1; i <= rsmd.getColumnCount(); i++) {
        System.out.println("Column Name: "          + rsmd.getColumnName(i));
        System.out.println("Nullable: "             + rsmd.isNullable(i));
        System.out.println("Precision: "            + rsmd.getPrecision(i));
        System.out.println("Scale: "                + rsmd.getScale(i));
        System.out.println("Size: "                 + rsmd.getColumnDisplaySize(i));
        System.out.println("Column Type: "          + rsmd.getColumnType(i));
        System.out.println("Column Type Name: "     + rsmd.getColumnTypeName(i));
        System.out.println("");
      }
    } catch (Exception e) {
    //异常处理
        System.out.println("Exception was thrown: " + e.getMessage());
    } finally { //关闭连接
        try {
          if (stmt != null)
            stmt.close();
          if (rs != null)
            rs.close();
          if (conn != null)
            conn.close();
        } catch (SQLException sqle) {
        //异常处理
            System.out.println("SQLException was thrown: " + sqle.getMessage());
        }
    }
  }
}