jdbc中的相关特性

java 代码     
用来获取相关表的外键

import java.sql.*;

public class ForeignKeysCoffees  {

   public static void main(String args[]) {

      String url = "jdbc:mySubprotocol:myDataSource";
      Connection con;
      String createString = "create table COFFEESFK " +
                        "(COF_NAME VARCHAR(32) NOT NULL, " +
                        "SUP_ID INTEGER, " +
                        "PRICE FLOAT, " +
                        "SALES INTEGER, " +
                        "TOTAL INTEGER, " +
                        "primary key(COF_NAME), " +
                        "foreign key(SUP_ID) references SUPPLIERSPK)";
      Statement stmt;

      try {
         Class.forName("myDriver.ClassName");

      } catch(java.lang.ClassNotFoundException e) {
         System.err.print("ClassNotFoundException: ");
         System.err.println(e.getMessage());
      }

      try {
         con = DriverManager.getConnection(url,
                               "myLogin", "myPassword");

         stmt = con.createStatement();
         stmt.executeUpdate(createString);

         DatabaseMetaData dbmd = con.getMetaData();
         ResultSet rs = dbmd.getImportedKeys(null, null, "COFFEESFK");
         while (rs.next()) {
            String pkTable = rs.getString("PKTABLE_NAME");
            String pkColName = rs.getString("PKCOLUMN_NAME");
            String fkTable = rs.getString("FKTABLE_NAME");
            String fkColName = rs.getString("FKCOLUMN_NAME");
            short updateRule = rs.getShort("UPDATE_RULE");
            short deleteRule = rs.getShort("DELETE_RULE");
            System.out.print("primary key table name :  ");
            System.out.println(pkTable);
            System.out.print("primary key column name :  ");
            System.out.println(pkColName);
            System.out.print("foreign key table name :  ");
            System.out.println(fkTable);
            System.out.print("foreign key column name :  ");
            System.out.println(fkColName);
            System.out.println("update rule:  " + updateRule);
            System.out.println("delete rule:  " + deleteRule);
            System.out.println("");
         }

         rs.close();
         stmt.close();
         con.close();

      } catch(SQLException ex) {
         System.err.print("SQLException: ");
         System.err.println(ex.getMessage());
      }
   }
}