使用java.sql.ResultSet是否有一种方法通过使用列的索引来获得列名作为字符串?我看了API文档,但什么都没找到。


当前回答

除了上面的答案,如果您正在使用一个动态查询,并且您想要列名,但不知道有多少列,您可以使用ResultSetMetaData对象首先获得列的数量,然后循环遍历它们。

修改Brian的代码:

ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM TABLE2");
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();

// The column count starts from 1
for (int i = 1; i <= columnCount; i++ ) {
  String name = rsmd.getColumnName(i);
  // Do stuff with name
}

其他回答

除了上面的答案,如果您正在使用一个动态查询,并且您想要列名,但不知道有多少列,您可以使用ResultSetMetaData对象首先获得列的数量,然后循环遍历它们。

修改Brian的代码:

ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM TABLE2");
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();

// The column count starts from 1
for (int i = 1; i <= columnCount; i++ ) {
  String name = rsmd.getColumnName(i);
  // Do stuff with name
}

这个问题很老了,以前的正确答案也很老了。但当我找到这个话题时,我想要的是类似这样的解。希望它能帮助到某些人。

// Loading required libraries    
import java.util.*;
import java.sql.*;

public class MySQLExample {
  public void run(String sql) {
    // JDBC driver name and database URL
    String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    String DB_URL = "jdbc:mysql://localhost/demo";

    // Database credentials
    String USER = "someuser"; // Fake of course.
    String PASS = "somepass"; // This too!

    Statement stmt = null;
    ResultSet rs = null;
    Connection conn = null;
    Vector<String> columnNames = new Vector<String>();

    try {
      // Register JDBC driver
      Class.forName(JDBC_DRIVER);

      // Open a connection
      conn = DriverManager.getConnection(DB_URL, USER, PASS);

      // Execute SQL query
      stmt = conn.createStatement();
      rs = stmt.executeQuery(sql);
      if (rs != null) {
        ResultSetMetaData columns = rs.getMetaData();
        int i = 0;
        while (i < columns.getColumnCount()) {
          i++;
          System.out.print(columns.getColumnName(i) + "\t");
          columnNames.add(columns.getColumnName(i));
        }
        System.out.print("\n");

        while (rs.next()) {
          for (i = 0; i < columnNames.size(); i++) {
            System.out.print(rs.getString(columnNames.get(i))
                + "\t");

          }
          System.out.print("\n");
        }

      }
    } catch (Exception e) {
      System.out.println("Exception: " + e.toString());
    }

    finally {
      try {
        if (rs != null) {
          rs.close();
        }
        if (stmt != null) {
          stmt.close();
        }
        if (conn != null) {
          conn.close();
        }
      } catch (Exception mysqlEx) {
        System.out.println(mysqlEx.toString());
      }

    }
  }
}

我知道,这个问题已经回答了,但可能像我这样的人需要通过标签而不是索引访问DatabaseMetaData的列名:

ResultSet resultSet = null;
DatabaseMetaData metaData = null;

    try {
        metaData  = connection.getMetaData();
        resultSet = metaData.getColumns(null, null, tableName, null);

        while (resultSet.next()){
            String name = resultSet.getString("COLUMN_NAME");
        }
    }
import java.sql.*;

public class JdbcGetColumnNames {

    public static void main(String args[]) {
        Connection con = null;
        Statement st = null;
        ResultSet rs = null;

        try {
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/komal", "root", "root");

            st = con.createStatement();

            String sql = "select * from person";
            rs = st.executeQuery(sql);
            ResultSetMetaData metaData = rs.getMetaData();

            int rowCount = metaData.getColumnCount();

            System.out.println("Table Name : " + metaData.getTableName(2));
            System.out.println("Field  \tDataType");

            for (int i = 0; i < rowCount; i++) {
                System.out.print(metaData.getColumnName(i + 1) + "  \t");
                System.out.println(metaData.getColumnTypeName(i + 1));
            }
        } catch (Exception e) {
            System.out.println(e);
        }
    }
}

表名:人 字段数据类型 id VARCHAR cname VARCHAR 强加于人的日期

SQLite 3

教科书getMetaData ();

DatabaseMetaData md = conn.getMetaData();
ResultSet rset = md.getColumns(null, null, "your_table_name", null);

System.out.println("your_table_name");
while (rset.next())
{
    System.out.println("\t" + rset.getString(4));
}

编辑:这也适用于PostgreSQL