我的搜索按钮代码在vb6.0中不起作用 [英] My search button code is not working in vb6.0

问题描述

请帮助，

我的搜索按钮代码无效。在错误之后我可以在查询表达式PID No ='105'或Name ='105'中看到patientdb.Refresh

语法错误（缺少运算符）。然后运行时错误2147217900（80040e14） ，方法'刷新对象IAdodc'失败。

我该如何解决这个问题。请帮助



这是我的代码



Private Sub searchbtn_Click（）

patientdb.Refresh

patientdb.RecordSource =select * from newpatient where PID No =' + txtsearch.Text +'或Name ='+ txtsearch.Text +'

如果patientdb.Recordset.EOF那么

MsgBox找不到记录，输入任何其他PID No或Name，vbCritical，消息

否则

patientdb.Caption = patientdb.RecordSource

结束如果



结束次级



我尝试过：



我的搜索按钮代码无效。错误后我可以看到patientdb.Refresh

语法错误（缺少运算符）在查询表达式PID No ='105'或Name ='105'中。然后运行时错误2147217900（80040e14），方法'刷新对象IAdodc'失败。

我该如何解决这个问题。请帮助

解决方案

不要这样做！永远不要连接字符串来构建SQL命令。它让您对意外或故意的SQL注入攻击持开放态度，这可能会破坏您的整个数据库。改为使用参数化查询。



连接字符串时会导致问题，因为SQL会收到如下命令：

  SELECT  *  FROM  MyTable  WHERE  StreetAddress = '  Baker' s Wood '   

就SQL而言，用户添加的引号会终止字符串，并且您会遇到问题。但情况可能更糟。如果我来并改为输入：x'; DROP TABLE MyTable; - 然后SQL收到一个非常不同的命令：

  SELECT  *  FROM  MyTable  WHERE  StreetAddress = '  x';  DROP  表 MyTable;   -   ' 

哪个SQL看作三个单独的命令：

  SELECT  *  FROM  MyTable  WHERE  StreetAddress = '  x'; 

完全有效的SELECT

  DROP   TABLE  MyTable; 

完全有效的删除表格通讯和

   -   ' 

其他一切都是评论。

所以它确实：选择任何匹配的行，从数据库中删除表，并忽略其他任何内容。



所以总是使用参数化查询！或者准备好经常从备份中恢复数据库。你经常定期备份，不是吗？



修复整个应用程序，你注意到的问题可能会在同一时间消失。

从newpatient中选择*，其中PID No = 

如果字段是字面意思称为PID No，包括空格，那么你需要使用方括号

 select from from newpatient，其中[PID No] = 

 patientdb.RecordSource =   select * from newpatient，其中PID No =' + txtsearch.Text +  '或Name =' + txtsearch.Text +  ' 

永远不要通过连接字符串来构建SQL查询。迟早，您将使用用户输入来执行此操作，这会打开一个名为SQL注入的漏洞，这对您的数据库很容易并且容易出错。

名称中的单引号你的程序崩溃。如果用户输入像Brian O'Conner这样的名称可能会使您的应用程序崩溃，那么这是一个SQL注入漏洞，崩溃是最少的问题，恶意用户输入，并且它被提升为具有所有凭据的SQL命令。

SQL注入 - 维基百科 [ ^ ]

SQL注入 [ ^ ]

按示例进行SQL注入攻击 [ ^ ]

PHP：SQL注入 - 手册 [ ^ ]

SQL注入预防备忘单 - OWASP [ ^ ]

Please help,
my search button code is not working. after the Error i can see "patientdb.Refresh"
syntax error (missing operator) in query expression "PID No = '105' or Name = '105'. Then run time error 2147217900 (80040e14), Method 'Refresh of object IAdodc' Failed.
How can i fix this. Please help

This is my code

Private Sub searchbtn_Click()
patientdb.Refresh
patientdb.RecordSource = "select * from newpatient where PID No ='" + txtsearch.Text + "'or Name ='" + txtsearch.Text + "'"
If patientdb.Recordset.EOF Then
MsgBox "Record Not Found,Enter any other PID No or Name", vbCritical, "Message"
Else
patientdb.Caption = patientdb.RecordSource
End If

End Sub

What I have tried:

my search button code is not working. after the Error i can see "patientdb.Refresh"
syntax error (missing operator) in query expression "PID No = '105' or Name = '105'. Then run time error 2147217900 (80040e14), Method 'Refresh of object IAdodc' Failed.
How can i fix this. Please help

解决方案

Don't do it like that! Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.

When you concatenate strings, you cause problems because SQL receives commands like:

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

Which SQL sees as three separate commands:

SELECT * FROM MyTable WHERE StreetAddress = 'x';

A perfectly valid SELECT

DROP TABLE MyTable;

A perfectly valid "delete the table" command

--'

And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.

So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?

Fix that throughout your app, and the problem you have noticed will probably disappear at the same time.

select * from newpatient where PID No =

If the field is literally called "PID No", including the space, then you need to use square brackets

select * from newpatient where [PID No] =

patientdb.RecordSource = "select * from newpatient where PID No ='" + txtsearch.Text + "'or Name ='" + txtsearch.Text + "'"

Never build an SQL query by concatenating strings. Sooner or later, you will do it with user inputs, and this opens door to a vulnerability named "SQL injection", it is dangerous for your database and error prone.
A single quote in a name and your program crash. If a user input a name like "Brian O'Conner" can crash your app, it is an SQL injection vulnerability, and the crash is the least of the problems, a malicious user input and it is promoted to SQL commands with all credentials.
SQL injection - Wikipedia[^]
SQL Injection[^]
SQL Injection Attacks by Example[^]
PHP: SQL Injection - Manual[^]
SQL Injection Prevention Cheat Sheet - OWASP[^]

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