Oracle大文本在ASP中存取问题的解决

发表于:2007-07-04来源:作者:点击数: 标签:
一、关于ADO 在基于Client/Server结构的 数据库 环境中,通过OLE DB接口可以存取数据,但它定义的是低层COM接口,不仅不易使用,而且不能被VB,VBA,VBScript等高级编程工具访问。而使用ADO则可以很容易地使VB等编程语言直接访问数据(通过OLE DB接口)。ADO

一、关于ADO

在基于Client/Server结构的数据库环境中,通过OLE DB接口可以存取数据,但它定义的是低层COM接口,不仅不易使用,而且不能被VB,VBA,VBScript等高级编程工具访问。而使用ADO则可以很容易地使VB等编程语言直接访问数据(通过OLE DB接口)。ADO是基于面向对象方法的,ADO对象模型总共才包括六个对象,相对于数据访问对象(DAO)来说简单得多。因此实际中常常使用它来访问数据库。

二、ADO访问数据库实例

下面,我们以Oracle为例,使用VB6.0来访问其数据库中的存储过程。在此例中,我们首先在Oracle数据库上创建有两个存储过程,一个不带参数,另一个带有参数。然后,使用ADO来访问这两个存储过程。步骤如下:

1. 在Oracle服务器上运行以下DDL脚本:

     DROP TABLE person;   CREATE TABLE person   (ssn NUMBER(9) PRIMARY KEY,   fname VARCHAR2(15),   lname VARCHAR2(20));   INSERT INTO person VALUES(555662222,'Sam','Goodwin');   INSERT INTO person VALUES(555882222,'Kent','Clark');   INSERT INTO person VALUES(666223333,'Jane','Doe');   COMMIT;   /
  

2. 在Oracle服务器上创建包(package):

  CREATE OR REPLACE PACKAGE packperson   AS   TYPE tssn is TABLE of NUMBER(10)   INDEX BY BINARY_INTEGER;   TYPE tfname is TABLE of VARCHAR2(15)   INDEX BY BINARY_INTEGER;   TYPE tlname is TABLE of VARCHAR2(20)   INDEX BY BINARY_INTEGER;      PROCEDURE allperson   (ssn OUT tssn,   fname OUT tfname,   lname OUT tlname);   PROCEDURE oneperson   (onessn IN NUMBER,   ssn OUT tssn,   fname OUT tfname,   lname OUT tlname);   END packperson;   /
  

3. 在Oracle服务器上创建以下包体(package body):

  CREATE OR REPLACE PACKAGE BODY packperson   AS   PROCEDURE allperson   (ssn OUT tssn,   fname OUT tfname,   lname OUT tlname)   IS   CURSOR person_cur IS   SELECT ssn, fname, lname   FROM person;   percount NUMBER DEFAULT 1;   BEGIN   FOR singleperson IN person_cur   LOOP   ssn(percount) := singleperson.ssn;   fname(percount) := singleperson.fname;   lname(percount) := singleperson.lname;   percount := percount + 1;   END LOOP;   END;   PROCEDURE oneperson   (onessn IN NUMBER,   ssn OUT tssn,   fname OUT tfname,   lname OUT tlname)   IS   CURSOR person_cur IS   SELECT ssn, fname, lname   FROM person   WHERE ssn = onessn;   percount NUMBER DEFAULT 1;   BEGIN   FOR singleperson IN person_cur   LOOP   ssn(percount) := singleperson.ssn;   fname(percount) := singleperson.fname;   lname(percount) := singleperson.lname;   percount := percount + 1;   END LOOP;   END;   END;   /
  

4. 在 VB 6.0 中打开一个新的工程,缺省创建表单 Form1。

5. 在表单上添加二个按钮,cmdGetEveryone和cmdGetOne。

6. 在代码窗口中添加以下代码:

     Option Explicit   Dim Cn As ADODB.Connection   Dim CPw1 As ADODB.Command   Dim CPw2 As ADODB.Command   Dim Rs As ADODB.Recordset   Dim Conn As String   Dim QSQL As String   Dim inputssn As Long      Private Sub cmdGetEveryone_Click()   Set Rs.Source = CPw1   Rs.Open   While Not Rs.EOF   MsgBox "Person data: " & Rs(0) & ",   " & Rs(1) & ", " & Rs(2)   Rs.MoveNext   Wend   Rs.Close   End Sub      Private Sub cmdGetOne_Click()   Set Rs.Source = CPw2   inputssn = InputBox(   "Enter the SSN you wish to retrieve:")   CPw2(0) = inputssn   Rs.Open   MsgBox "Person data: " & Rs(0) & "   , " & Rs(1) & ", " & Rs(2)   Rs.Close   End Sub      Private Sub Form_Load()   '使用合适的值代替以下用户ID,   口令(PWD)和服务器名称(SERVER)   Conn = "UID=*****;PWD=*****;driver=" _   & "{Microsoft ODBC for   Oracle};SERVER=dseOracle;"   Set Cn = New ADODB.Connection   '创建Connection对象   With Cn   .ConnectionString = Conn   .CursorLocation = adUseClient   .Open   End With   QSQL = "{call packperson.allperson(   {resultset 9,ssn,fname,"_   & "lname})}"   Set CPw1 = New ADODB.Command   '创建Command对象   With CPw1   Set .ActiveConnection = Cn   .CommandText = QSQL   .CommandType = adCmdText   End With   QSQL ="{call packperson.oneperson(?,   {resultset 2,ssn, "_   & " fname,lname})}"   '调用存储过程   Set CPw2 = New ADODB.Command   With CPw2   Set .ActiveConnection = Cn   .CommandText = QSQL   .CommandType = adCmdText   .Parameters.Append.CreateParameter(   ,adInteger, _   adParamInput)   '添加存储过程参数   End With   Set Rs = New ADODB.Recordset   With Rs   .CursorType = adOpenStatic   .LockType = adLockReadOnly   End With   End Sub      Private Sub Form_Unload(Cancel As Integer)   Cn.Close   Set Cn = Nothing   Set CPw1 = Nothing   Set CPw2 = Nothing   Set Rs = Nothing   End Sub
  

7. 运行程序。当点下cmdGetEveryone按钮时,程序调用Oracle数据库中不带参数的存储过程packperson.allperson,点下cmdGetOne按钮时调用packperson.oneperson存储过程。

原文转自:http://www.ltesting.net