如何使用 MySQL 在 Java 中取得 ResultSet 上的列名稱？

要取得結果集中的列名，您需要使用getMetaData()方法。 getMetadata()的原型如下−

ResultSetMetaData getMetaData throws SQLException;

Create a MySQL table with 5 column names. The query to create a table is as follows −

mysql> create table javagetallcolumnnames
   -> (
   -> Id int NOT NULL AUTO_INCREMENT,
   -> Name varchar(20),
   -> Age int,
   -> Salary float,
   -> Address varchar(100),
   -> PRIMARY KEY(Id)
   -> );
Query OK, 0 rows affected (1.34 sec)

以下是取得ResultSet中列名的Java程式碼。程式碼如下−

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import com.mysql.jdbc.ResultSetMetaData;
public class GetAllColumnNames {
   public static void main(String[] args) {
      String JdbcURL="jdbc:mysql://localhost:3306/test?useSSL=false";
      String Username="root";
      String password="123456";
      Connection con=null;
      Statement stmt=null;
      ResultSet rs;
      try {
         con = DriverManager.getConnection(JdbcURL, Username, password);
         stmt=con.createStatement();
         rs = stmt.executeQuery("SELECT *FROM javagetallcolumnnames");
         ResultSetMetaData md = (ResultSetMetaData) rs.getMetaData();
         int counter = md.getColumnCount();
         String colName[] = new String[counter];
         System.out.println("The column names are as follows:");
         for (int loop = 1; loop <= counter; loop++) {
            colName[loop-1] = md.getColumnLabel(loop);
            System.out.println(colName[loop-1]);
         }
      } catch(Exception e) {
         e.printStackTrace();
      }
   }
}

Here is the snapshot of the code −

The following is the output −

#

The column names are as follows:
Id
Name
Age
Salary
Address

這是範例輸出的快照−

#

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