simpleselect.java

weblogic应用全实例

//声明本类包含在包examples.jdbc.oracle中
package examples.jdbc.oracle;
//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[])
       throws Exception
  {
  //声明属性变量	
    Properties props = new Properties();
    props.put("user","scott");
    props.put("password","tiger");
    props.put("server","DEMO");
	//加载数据库驱动程序weblogic.jdbc.oci.Driver
    Driver myDriver = (Driver) Class.forName("weblogic.jdbc.oci.Driver").newInstance();
      //创建连接，连接数据库jdbc:weblogic:oracle
    Connection conn = myDriver.connect("jdbc:weblogic:oracle", props);
    //创建SQL语句对象stmt
    Statement stmt = conn.createStatement();
    //执行SQL语句，查询表empdemo中的所有记录
        stmt.execute("select * from empdemo");
    	//获取结果集
        ResultSet rs = stmt.getResultSet();
    
    //也可以直接用    ResultSet rs = stmt.executeQuery("select * from empdemo");
    //打印查询结果，打印所有记录
    while (rs.next()) {
      System.out.println(rs.getString("empid") + " - " + 
                         rs.getString("name")  + " - " + 
                         rs.getString("dept"));
    }
    //获取数据集元数据对象
    ResultSetMetaData rsmd = rs.getMetaData();
    //获取列数并打印
    System.out.println("Number of Columns: " + rsmd.getColumnCount());
    //获取并打印表结构信息
    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("");
    }
    //关闭
    stmt.close();
    conn.close();
  }
}