我的VB.Net代码中的PL SQL错误，但无法在SQL Developer中重现

Question

ORA-06502：PL / SQL：数字或值错误ORA-06512：位于“ JOHN.GET_USERS_EMAIL”的第7行ORA-06512：第1行

当我在SQL Developer中运行过程并在应用程序中使用值时，它可以正常工作。当我运行VB.Net代码时，出现异常（如上所示）

我不知道我做错了什么。 （Oracle过程不是由我编写的。它是由另一个不再在这里工作的人编写的。）>

Oracle中的步骤

create or replace PROCEDURE "GET_USERS_EMAIL" (
User_Email_P OUT VARCHAR,
Employee_P IN VARCHAR
)
As 
Begin
SELECT USER_EMAIL INTO User_Email_P FROM
EMPLOYEE
WHERE
USER_ID = Employee_P;
end; 
VB.Net中的代码

Public Function Get_A_Users_Email(ByVal strEmpId As String) As String
    Try
        Dim rValue As String = ""
        Dim strSQL As String = "JOHN.GET_USERS_EMAIL"
        Dim cmd As OracleCommand = dba.CreateStoredProcCommand(strSQL)
        cmd.BindByName = True
        Dim oracleParameter(1) As OracleParameter
        oracleParameter(0) = New OracleParameter()
        oracleParameter(1) = New OracleParameter()
        strEmpId = UCase(strEmpId.Trim())

        With cmd
            oracleParameter(0) = cmd.Parameters.Add(name:="User_Email_P", dbType:=OracleDbType.Varchar2, direction:=ParameterDirection.Output)
            oracleParameter(1) = cmd.Parameters.Add(name:="Employee_P", dbType:=OracleDbType.Varchar2, val:=strEmpId, ParameterDirection.Input)

        End With

        dba.ExecuteScaler(cmd)

        If String.IsNullOrEmpty(cmd.Parameters("User_Email_P").Value.ToString) = True Then
            rValue = 0
        Else
            rValue = cmd.Parameters("User_Email_P").Value.ToString
        End If

        Return rValue
    Catch ex As Exception
        Dim Err As New App_Errors("App_Users", "Get_A_Users_Email", ex)
        Return Nothing
    End Try
End Function

Public Function ExecuteScaler(ByVal cmd As OracleCommand) As String
    ' the value tobe return ...
    Dim value As String = ""
    Dim oValue As Object
    Dim bValue As Boolean = False
    ' execute command ...
    Try
        ' open connection ...
        cmd.Connection.Open()
    Catch ex As Exception
        MsgBox("Unable to establish a connection to CFR database." & ex.ToString, MsgBoxStyle.Critical)
        Return value = ""
        Exit Function
    End Try
    Try

        ' execute command ... convert type in the case of return value null ...
        oValue = cmd.ExecuteScalar
        bValue = Convert.IsDBNull(oValue)
        If Not (bValue) Then
            value = CType(oValue, String)
        Else
            value = ""
        End If
    Catch ex As Exception
        ' rethrow error ...
        ' Dim Err As New App_Errors("Data_Access_Class", "ExecuteScalar", ex)
        Throw New Exception(ex.InnerException.ToString, ex)
    Finally
        cmd.Connection.Close()
    End Try
    Return value
End Function

Public Function CreateStoredProcCommand(ByVal cmdtext As String) As OracleCommand
    Dim Cmd As New OracleCommand        ' command object ...
    ' create command ...
    With Cmd
        .Connection = Conn
        .CommandText = cmdtext
        .CommandType = CommandType.StoredProcedure
    End With
    Return Cmd
End Function
这里是表的DDL。

CREATE TABLE "JOHN"."EMPLOYEE" 
   (    "EMPLOYEE_NUMBER" NUMBER(9,0), 
    "LOCATION_CODE" VARCHAR2(4 BYTE), 
    "SECURITY_LEVEL" NUMBER(2,0), 
    "DATE_LAST_UPDATE" DATE, 
    "DATE_SECURITY_ASSIGNED" DATE, 
    "LAST_PASSWORD_DATE" DATE, 
    "CURRENT_PASSWORD" VARCHAR2(8 BYTE), 
    "FIRST_NAME" VARCHAR2(20 BYTE), 
    "MIDDLE_INITIAL" VARCHAR2(1 BYTE), 
    "LAST_NAME" VARCHAR2(30 BYTE), 
    "USER_ID" VARCHAR2(8 BYTE), 
    "USER_TYPE" CHAR(1 BYTE), 
    "INACTIVE_DATE" DATE, 
    "SECURITY_ASSIGNED_BY" VARCHAR2(8 BYTE), 
    "PASSWORD_EXPIRATION_DATE" DATE, 
    "STATUS_CODE" NUMBER(2,0), 
    "ACCOUNT_LOCKED" VARCHAR2(1 BYTE), 
    "UPDATE_PASS_ON_SIGNON" VARCHAR2(1 BYTE), 
    "USER_EMAIL" VARCHAR2(30 BYTE))
[请注意，DDL，存储过程和VB.Net代码是以前的开发人员留下的。我正在将Microsoft的Oracle驱动程序的实现替换为ODP.Net。除此之外，代码上没有任何其他更改。

ORA-06502：PL / SQL：数字或值错误ORA-06512：在“ JOHN.GET_USERS_EMAIL”，第7行ORA-06512：在第1行当我在SQL Developer中运行过程并在应用程序中使用值时，它的工作原理...

Answer 1

将数据库对象保留在使用它们的方法的本地。这样，您可以控制何时将它们关闭和处置。连接和命令可能包含非托管代码，需要使用它们各自的.Dispose方法来释放它们。在此示例中，即使有错误，Using...End Using块也会为您处理。