此程序都是企业级 的数据库开发程序 全面揭示了JAVA对数据库的操作

				package metadata;
				
				import java.util.*;
				import java.sql.*;
				import connections.*;
				
				public class GenSql {
				  public static void main(String args[]) {
				    Connection conn = null;
				
				    try {
				      conn = ConnectionFactory.getConnection();
				      DatabaseMetaData dbmd = conn.getMetaData();
				
				      String[] tableTypes = new String[] {
				        "TABLE"
				      };
				      ResultSet tables = dbmd.getTables(null, "APP", null, tableTypes);
				      Vector vtables = new Vector();
				
				      String aTable;
				
				      // build up a list of tables
				      while (tables.next()) {
				        aTable = tables.getString("TABLE_NAME");
				        vtables.add(aTable);
				      } 
				
				      ConnectionFactory.close(tables);
				
				      Iterator iterator = vtables.iterator();
				
				      // for each table in the list...
				      String separator;
				      while (iterator.hasNext()) {
				        aTable = (String) iterator.next();
				
				        // print the create table...
				        System.out.print("create table " + aTable + " (");
				
				        // print the columns
				        ResultSet columns = dbmd.getColumns(null, null, aTable, null);
				        separator = "";
				        while (columns.next()) {
				          String aColumn;
				
				          System.out.print(separator);
				          System.out.print(columns.getString("COLUMN_NAME"));
				
				          int dataType = columns.getInt("DATA_TYPE");
				          System.out.print(" " + columns.getString("TYPE_NAME"));
				
				          if (dataType == java.sql.Types.CHAR 
				                  || dataType == java.sql.Types.VARCHAR) {
				            System.out.print("(" + columns.getString("COLUMN_SIZE") + ")");
				          } 
				
				          String isNullable = columns.getString("IS_NULLABLE");
				          if (isNullable.equalsIgnoreCase("no")) {
				            System.out.print(" NOT NULL");
				          } 
				
				          separator = ", ";
				        } 
				
				        // print the primary keys
				        ResultSet pkeys = dbmd.getPrimaryKeys(null, null, aTable);
				        String pkInfo = ", primary key(";
				
				        separator = "";
				        int pkCount = 0;
				        while (pkeys.next()) {
				          pkInfo = pkInfo.concat(separator 
				                                 + pkeys.getString("COLUMN_NAME"));
				          separator = ", ";
				          pkCount++;
				        } 
				        pkInfo = pkInfo.concat(")");
				
				        // if there were primary keys defined, add the pk statement
				        if (pkCount > 0) {
				          System.out.print(pkInfo);
				
				        } 
				        System.out.println(")\n");
				      } 
				    } catch (Exception e) {
				      e.printStackTrace();
				    } 
				    finally {
				      ConnectionFactory.close(conn);
				    } 
				  } 
				}