我似乎无法弄清楚下面的代码有什么问题。该方法getSalaryAverageDepartment
调用模式中get_salary_average_dept
属于EMP_PGK
包的 PL/SQL 过程HR
。
public float getSalaryAverageDepartment(int deptId)
{
Connection conn = null;
CallableStatement callStmt = null;
Float avgDeptSal = -1f;
try
{
// Register the Jdbc Driver
// Class.forName(JDBC_DRIVER_ORACLE);
// Create a database connection
conn = DriverManager.getConnection(DB_URL,DB_USER,DB_PWD);
// Create a SQL String
String callProc = "{ call HR.EMP_PKG.get_salary_average_dept( ? , ? )}";
// Create a callable statement
callStmt = conn.prepareCall(callProc);
// Bind value to the IN parameter
callStmt.setInt(1, java.sql.Types.NUMERIC);
// Register the OUT parameter's type to the SQL type of the return value
callStmt.registerOutParameter(2, java.sql.Types.FLOAT);
// Execute the callable statement
callStmt.execute();
// Retrieve the OUT parameter
avgDeptSal = callStmt.getFloat(2);
System.out.println("Department with Id : "+ deptId + " has average employee salary of : " + avgDeptSal);
}
catch (SQLException se)
{
System.out.println("Exception occured in the database");
System.out.println("Exception message: "+ se.getMessage());
System.out.println("Dataabse error code: "+ se.getErrorCode());
se.printStackTrace();
}
finally
{
// Clean up
if(callStmt != null)
{
try
{
callStmt.close();
}
catch (SQLException se2)
{
se2.printStackTrace();
}
}
if(conn != null)
{
try
{
conn.close();
}
catch (SQLException se2)
{
se2.printStackTrace();
}
}
}
return avgDeptSal;
}
这里 id 调用上述代码的 main 方法:
public static void main(String[] args)
{
HrManager hrMngr = new HrManager();
int deptId = 80;
hrMngr.getSalaryAverageDepartment(deptId);
}
以下是 PL/SQL 过程:
-- Purpose: Returns the average salary of a department with given id
PROCEDURE get_salary_average_dept(dept_id IN departments.department_id%type, avg_salary OUT FLOAT) IS
BEGIN
SELECT AVG(CAST(salary as FLOAT))
INTO avg_salary
FROM employees
WHERE department_id = dept_id;
dbms_output.put_line('Average salary for department with id : '|| dept_id ||' is : '|| avg_salary);
EXCEPTION
WHEN NO_DATA_FOUND THEN
dbms_output.put_line('No department found with id: '|| dept_id);
WHEN others THEN
dbms_output.put_line('Error!');
END get_salary_average_dept;
这是java程序的输出:
Department with Id : 80 has average employee salary of : 0.0
我在 Jdeveloper 中独立执行了 PL/SQL 过程,输出如下:
Connecting to the database Insight_Dev_Hr.
Average salary for department with id : 80 is : 9000
Process exited.
为什么两个输出不同。我在这里错过了什么吗?