java - java中出现错误 "ORA-00942: table or view does not exist "

Question

我正在尝试学习连接到oracle数据库

当我以这种方式登录 sqlplus 时:

sqlplus sys/Oracle_1@orcl as sysdba;

我运行这段代码:

连接 hr/hr@orclpdb

从员工中选择count(*)；

我得到这个输出:

 COUNT(*)
----------
       107

但是当我尝试在 java 代码中访问此表时，出现此错误:

ORA-00942: 表或 View 不存在

这是我的java代码:

class OracleCon{  
public static void main(String args[]){  
try{  
Class.forName("oracle.jdbc.driver.OracleDriver");  
Connection con=DriverManager.getConnection(  
        "jdbc:oracle:thin:hr/hr@localhost:1521/orclpdb","sys as sysdba","Oracle_1"); 
Statement stmt=con.createStatement();  
ResultSet rs=stmt.executeQuery("select count(*) from employees");  
while(rs.next())  
System.out.println(rs.getInt(1)+"  "+rs.getString(2)+"  "+rs.getString(3));  
con.close();  
}catch(Exception e){ System.out.println(e);}  

}  
}  

我应该怎么做才能解决这个问题？

Answer 1

您正在尝试在 Java 代码中使用 sys 用户连接它，但表 employee 存在于 hr 架构中。

您可以更改:

//Change this line from

Connection con=DriverManager.getConnection(  
        "jdbc:oracle:thin:hr/hr@localhost:1521/orclpdb","sys as sysdba","Oracle_1"); 

// to

Connection con=DriverManager.getConnection(  
        "jdbc:oracle:thin:hr/hr@localhost:1521/orclpdb","hr","hr"); 

或者

您可以更改从表 employee 中获取数据的方式(使用其架构查询表)

//Change this line from
ResultSet rs=stmt.executeQuery("select count(*) from employees"); 
//to
ResultSet rs=stmt.executeQuery("select count(*) from hr.employees"); 

干杯!!