实现从MySql数据库中查看所有的表及其对应的列数

这里简单实现了从数据库中，查看所有的表及其对应的列数

 

try {
			 Class.forName("com.mysql.jdbc.Driver");
			 String url = "jdbc:mysql://localhost:3306/test"; //  3306/后边是数据库名
			 String user = "root";
			 String passWord = ""; //这里添加数据库登陆密码
			 Connection conn = DriverManager.getConnection(url, user, passWord);
			 if(conn != null)
			 {
				 System.out.println("数据库连接成功");
			 }
			 
			 DatabaseMetaData dbmd = conn.getMetaData();

			 String[] types = { "TABLE" };
			 ResultSet resultSet = dbmd.getTables(null, null, "%", types);
			 
			 String sqlStr = "";
			 PreparedStatement ps = null;
		     ResultSet rs = null;
			 
			 while (resultSet.next()) {
				 String tableName = resultSet.getString("TABLE_NAME");
			   /*  String tableCatalog = resultSet.getString(1);
			     String tableSchema = resultSet.getString(2);
			     System.out.println(tableName + "   "+tableCatalog + "  "+ tableSchema);*/
				 sqlStr = "select count(*) as columNum from information_schema.columns where table_name= \'" + tableName + "\'";
				 ps = conn.prepareStatement(sqlStr);
				 rs = ps.executeQuery();
				 rs.next();
				 System.out.println(tableName + "	" + rs.getString("columNum"));
			 }
			 ps.close();
			 rs.close();
			 resultSet.close();
			 conn.close();
			 
		 }catch(Exception e)
		 {
			 e.printStackTrace();
		 }