java 通過數據庫名獲得 該數據所有的表名以及字段名、字段類型

package com.nf.lc.sql_meta_data;

import java.sql.*;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * 獲得數據庫表的元數據
 */
public class GetSQLMetaData {

    public static void main(String[] args) throws SQLException, ClassNotFoundException {

        HashMap<String, Object> computer_mall = (HashMap<String, Object>) getDatabaseNameToTableNameAndColumnName("computer_mall");

        Set<String> tableNames = computer_mall.keySet();
        System.out.println("一共有表：" + tableNames.size() + "張");
        for (String tableName : tableNames) {
            System.out.println("===========================\r\n");
            System.out.println("表名：" + tableName);

            // <字段名,類型>  HashMap 集合
            HashMap<String, String> columnNames = (HashMap<String, String>) computer_mall.get(tableName);

            Set<String> columns = columnNames.keySet();

            for (String column : columns) {
                System.out.println("字段名：" + column + " 類型：" + columnNames.get(column));
            }

            System.out.println("===========================\r\n");
        }


    }

    public static Map getDatabaseNameToTableNameAndColumnName(String databaseName) throws SQLException, ClassNotFoundException {

        String driver = "org.mariadb.jdbc.Driver";
        String url = "jdbc:mariadb://localhost:3306/" + databaseName;
        String username = "root";
        String password = "root";
        Map<String, Object> tableNameMap = new HashMap<>();


        //加載驅動
        Class.forName(driver);

        //獲得數據庫連接
        Connection connection = DriverManager.getConnection(url, username, password);
        //獲得元數據
        DatabaseMetaData metaData = connection.getMetaData();
        //獲得表信息
        ResultSet tables = metaData.getTables(null, null, null, new String[]{"TABLE"});

        while (tables.next()) {
            Map<String, String> columnNameMap = new HashMap<>(); //保存字段名

            //獲得表名
            String table_name = tables.getString("TABLE_NAME");
            //通過表名獲得所有字段名
            ResultSet columns = metaData.getColumns(null, null, table_name, "%");
            //獲得所有字段名
            while (columns.next()) {
                //獲得字段名
                String column_name = columns.getString("COLUMN_NAME");
                //獲得字段類型
                String type_name = columns.getString("TYPE_NAME");

                columnNameMap.put(column_name, type_name);
            }

            tableNameMap.put(table_name, columnNameMap);

        }

        return tableNameMap;
    }


}

 

 關於獲得數據庫相關信息：

 

       String driver = "org.mariadb.jdbc.Driver";
        String url = "jdbc:mariadb://localhost:3306/" + databaseName;
        String username = "root";
        String password = "root";

        //加載驅動
        Class.forName(driver);

        //獲得數據庫連接
        Connection connection = DriverManager.getConnection(url, username, password);
        //獲得元數據
        DatabaseMetaData metaData = connection.getMetaData();
        
        //獲得數據庫名稱
        String databaseProductName = metaData.getDatabaseProductName();

        //獲得數據庫版本號
        String databaseProductVersion = metaData.getDatabaseProductVersion();

        //獲得數據庫用戶名
        String userName = metaData.getUserName();

        //獲得數據庫連接URL
        String jdbcUrl = metaData.getURL();

        //獲得數據庫驅動
        String driverName = metaData.getDriverName();

        //獲得數據庫驅動版本號
        String driverVersion = metaData.getDriverVersion();

 

 

 

 

 

歸途(LC)