想要遍历一个结果集中的每一行,包括每一列,但不知道有多少列及每列的类型?
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JDBCExample {
public static void main(String[] args) {
try {
//System.setProperty("jdbc.drivers","oracle.jdbc.driver.OracleDriver");
Class.forName("oracle.jdbc.driver.OracleDriver");
String url = "jdbc:oracle:thin:@localhost:1521:orcl";
Connection conn = DriverManager.getConnection(url,"scott","123");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from dept");
while (rs.next()){//假如这里不知道列有多少,及每一列的字体类型?
System.out.print("DeptNo:" + rs.getInt(1));
System.out.print("\tDeptName:" + rs.getString(2));
System.out.println("\tLOC:" + rs.getString(3));
}
rs.close();
stmt.close();
conn.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
catch(SQLException e){
e.printStackTrace();
}
}
}
[code="java"] public static void main(String[] args) throws Exception {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@localhost:1521:gdda";
String user = "scott";
String pass = "123";
//
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, user, pass);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from dept");
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
// 输出列名
for (int i=1; i<=columnCount; i++){
System.out.print(rsmd.getColumnName(i));
System.out.print("(" + rsmd.getColumnTypeName(i) + ")");
System.out.print(" | ");
}
System.out.println();
// 输出数据
while (rs.next()){
for (int i=1; i<=columnCount; i++){
System.out.print(rs.getObject(i) + " | ");
}
System.out.println();
}
rs.close();
stmt.close();
conn.close();
}[/code]
用 ResultSetMetaData
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
得到结果集的列数
while(rs.next()){
for(int i = 0 ; i <columnCount;i++){
//rs.getString(i)
}
}
类型对你来说重要吗?你这里不是反射封装,如果是反射封装,你应该有映射关系来获取类型
既然不做封装直接返回字符出或者Object 都行啊