java连接oracle修改表显示id标识符错误。

代码：
package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;

public class jdbctest1 {
public static void main(String[] args) throws Exception {
    Class.forName("oracle.jdbc.driver.OracleDriver");
    String url="jdbc:oracle:thin:@localhost:1521:orcl";
    String user="scott";
    String password="root123";
    Connection conn = DriverManager.getConnection(url, user, password);
//    String sql="insert into t1 (id,name) values (1,'王')";
    String sql="update stu set id=456 where name='vae'";
    Statement st = conn.createStatement();
    st.execute(sql);
    st.close();
    conn.close();
}
}
显示错误：
Exception in thread "main" java.sql.SQLSyntaxErrorException: ORA-00904: "NAME": 标识符无效

    at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:91)
    at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:133)
    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:206)
    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:455)
    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:413)
    at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:1034)
    at oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:183)
    at oracle.jdbc.driver.T4CStatement.executeForRows(T4CStatement.java:942)
    at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1222)
    at oracle.jdbc.driver.OracleStatement.executeInternal(OracleStatement.java:1770)
    at oracle.jdbc.driver.OracleStatement.execute(OracleStatement.java:1739)
    at oracle.jdbc.driver.OracleStatementWrapper.execute(OracleStatementWrapper.java:299)
    at jdbc.jdbctest1.main(jdbctest1.java:17)