如何使用 JDBC 獲取所有資料庫的列表?


可以使用 SHOW DATABASES 查詢獲取 MySQL 中的資料庫列表。

show databases;

以下 JDBC 程式透過執行顯示資料庫查詢來檢索資料庫列表。

示例

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class ShowDatabasesExample {
   public static void main(String args[]) throws Exception {
      //Registering the Driver
      DriverManager.registerDriver(new com.mysql.jdbc.Driver());
      //Getting the connection
      String mysqlUrl = "jdbc:mysql:///mydatabase";
      Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
      System.out.println("Connection established......");
      //Creating a Statement object
      Statement stmt = con.createStatement();
      //Retrieving the data
      ResultSet rs = stmt.executeQuery("Show Databases");
      System.out.println("List of databases: ");
      while(rs.next()) {
         System.out.print(rs.getString(1));
         System.out.println();
      }
   }
}

輸出

Connection established......
List of databases:
information_schema
base
details
errors
logging
mydatabase
mydb
mysql
performance_schema
sample_database
sampledb
students
sys
testdb
world

或者,可以使用 DatabaseMetaData 介面的 getCatalogs() 方法。

示例

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
public class ListOfAllDatabases {
   public static void main(String args[]) throws Exception {
      //Registering the Driver
      DriverManager.registerDriver(new com.mysql.jdbc.Driver());
      //Getting the connection
      String mysqlUrl = "jdbc:mysql:///mydatabase";
      Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
      System.out.println("Connection established......");
      //Retrieving the meta data object
      DatabaseMetaData metaData = con.getMetaData();
      //Retrieving the list of database names
      ResultSet tables = metaData.getCatalogs();
      while (tables.next()) {
         System.out.println(tables.getString("TABLE_CAT"));
      }
   }
}

輸出

Connection established......
List of databases:
information_schema
base
details
errors
logging
mydatabase
mydb
mysql
performance_schema
sample_database
sampledb
students
sys
testdb
world

更新日期: 30-Jul-2019

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