SqlHelper（二）

一 数据连接



 
Public
 sqlconn 
As
 SqlClient.SqlConnection  
'
全局变量，供整个应用程序使用





  
Sub
 open_conn()

        
Dim
 sqlconnStr 
As
 
String




        
Try


                     sqlconnStr 
=
 
"
workstation id=
"
 
+
 DbHost 
+
 
"
;packet size=4096;data source = 
"
 sqlserver主机 
"
 ;persist security info=true;initial catalog = dbName; user id = userName; password =userPwd            sqlconn = New SqlClient.SqlConnection(sqlconnStr)



                 
Catch
 ex 
As
 Exception

            
MsgBox
(ex.ToString)

        
End
 
Try


        
'
 MsgBox("数据库连接准备完成")





    
End Sub




二 日志记录类




'
系统日志类


'
该类供应用各个模块调用，记录用户的登陆，退出，对数据库的操作，以及运行过程中系统的异常的记录。


'
该类的成员变量为结构体loginfo的一个实例



Public
 
Class
 cLogWrite

    
Private
 myLogInfo 
As
 
New
 logInfo  ’定义的一个结构体类型的公共变量，包含用户，日志类型，主机，和日‘志内容

    
Public
 
Sub
 setUserId(
ByVal
 myId 
As
 
String
)

        myLogInfo.user_id 
=
 myId

    
End Sub


    
Public
 
Sub
 setLogType(
ByVal
 myType 
As
 
String
)

        myLogInfo.log_type 
=
 myType

    
End Sub


    
Public
 
Sub
 setLogContent(
ByVal
 myContent 
As
 
String
)

        myLogInfo.log_content 
=
 myContent

    
End Sub


    
Public
 
Sub
 setLogMachine()

        myLogInfo.log_machine 
=
 System.Net.Dns.GetHostName

    
End Sub


    
Public
 
Sub
 insertLog()

        
Dim
 mysqlcomm 
As
 SqlClient.SqlCommand

        
Dim
 mysql 
As
 
String


        mysql 
=
 
"
insert into wjb_log(log_datetime,log_type,user_id,log_content,log_machine) values (current_timestamp,'
"
 
+
 myLogInfo.log_type 
+
 
"
','
"
 
+
 myLogInfo.user_id 
+
 
"
','
"
 
+
 myLogInfo.log_content 
+
 
"
','
"
 
+
 myLogInfo.log_machine 
+
 
"
')
"


        
Try


            sqlconn.Open()

            mysqlcomm 
=
 
New
 SqlClient.SqlCommand(mysql, sqlconn)

            mysqlcomm.ExecuteNonQuery()

            sqlconn.Close()

        
Catch
 ex 
As
 Exception

            
If
 sqlconn.State.Open 
=
 
1
 
Then


                sqlconn.Close()

            
End
 
If


            
Throw
 ex

            
Exit Sub


        
End
 
Try


    
End Sub





End Class




三 数据库操作




'
该类为数据处理类，定义了所有对数据库的操作


'
该类为所有功能模块提供对数据库数据的操作接口，select、insert、update、delete



Public
 
Class
 cDataProcess

    
'
该方法为各功能模块 查询数据库中的数据提供结果集，输入select sql语句，和操作的数据库表，返回相应表的结果集



    
Dim
 myLogWrite 
As
 
New
 cLogWrite

    
Public
 
Function
 dataSelect(
ByVal
 strSql 
As
 
String
, 
ByVal
 strTableName 
As
 
String
) 
As
 DataSet

        
Dim
 mydataset 
As
 
New
 DataSet

        
Dim
 mySqlAdapter 
As
 SqlClient.SqlDataAdapter



        
Try


            sqlconn.Open()

            mySqlAdapter 
=
 
New
 SqlClient.SqlDataAdapter(strSql, sqlconn)

            mySqlAdapter.Fill(mydataset, strTableName)

            sqlconn.Close()

            mySqlAdapter 
=
 
Nothing


            
'
该处记录查询的日志信息，日志类型为：用户操作，用户内容包括查询语句，查询的表



            
'
myLogWrite.setLogType("用户操作")



            
'
myLogWrite.setUserId(userStruc.userid)



            
'
myLogWrite.setLogMachine()



            
'
myLogWrite.setLogContent("用户通过 " + strSql + " 查询表 " + strTableName)



            
'
myLogWrite.insertLog()



        
Catch
 ex 
As
 Exception

            sqlconn.Close()

            
'
该处记录日志信息，日志类型为操作异常



            myLogWrite.setLogType(
"
系统异常
"
)

            myLogWrite.setUserId(userStruc.userid)

            myLogWrite.setLogMachine()

            myLogWrite.setLogContent(
""
 
+
 ex.Message) 
'
"用户查询表 " + strTableName + " 时发生异常：



            myLogWrite.insertLog()



            
Throw
 ex

        
End
 
Try


        
Return
 mydataset

    
End Function


    
'
该方法为各功能模块提供插入数据操作，参数为：insert语句和表名



    
Public
 
Sub
 dataInsert(
ByVal
 strSql 
As
 
String
, 
ByVal
 strTableName 
As
 
String
)

        
Dim
 mysqlcomm 
As
 SqlClient.SqlCommand



        
Try


            sqlconn.Open()

            mysqlcomm 
=
 
New
 SqlClient.SqlCommand(strSql, sqlconn)

            mysqlcomm.ExecuteNonQuery()

            sqlconn.Close()

            mysqlcomm 
=
 
Nothing


            
'
该处记录日志信息，日志类型为：用户操作，用户内容包括insert语句，操作的表



            myLogWrite.setLogType(
"
用户操作
"
)

            myLogWrite.setUserId(userStruc.userid)

            myLogWrite.setLogMachine()

            myLogWrite.setLogContent(
"
用户向表  
"
 
+
 strTableName 
+
 
"
 中插入数据
"
)

            myLogWrite.insertLog()

        
Catch
 ex 
As
 Exception

            
If
 sqlconn.State.Open 
=
 
1
 
Then


                sqlconn.Close()

            
End
 
If




            
'
该处记录日志信息，日志类型为操作异常



            myLogWrite.setLogType(
"
系统异常
"
)

            myLogWrite.setUserId(userStruc.userid)

            myLogWrite.setLogMachine()

            myLogWrite.setLogContent(
""
 
+
 escapeZifu(ex.Message, 
"
'
"
)) 
'
用户向表 " + strTableName + " 中插入数据时发生异常：



            myLogWrite.insertLog()

            
Throw
 ex

        
End
 
Try


    
End Sub


    
'
该方法为各功能模块提供修改数据操作，参数为：update语句和表名



    
Public
 
Sub
 dataUpdate(
ByVal
 strSql 
As
 
String
, 
ByVal
 strTableName 
As
 
String
)

        
Dim
 mysqlcomm 
As
 SqlClient.SqlCommand



        
Try


            sqlconn.Open()

            mysqlcomm 
=
 
New
 SqlClient.SqlCommand(strSql, sqlconn)

            mysqlcomm.ExecuteNonQuery()

            sqlconn.Close()

            mysqlcomm 
=
 
Nothing


            
'
该处记录日志信息，日志类型为：用户操作，用户内容包括insert语句，操作的表



            myLogWrite.setLogType(
"
用户操作
"
)

            myLogWrite.setUserId(userStruc.userid)

            myLogWrite.setLogMachine()

            myLogWrite.setLogContent(
"
用户更改表  
"
 
+
 strTableName 
+
 
"
的记录
"
)

            myLogWrite.insertLog()

        
Catch
 ex 
As
 Exception

            
If
 sqlconn.State.Open 
=
 
1
 
Then


                sqlconn.Close()

            
End
 
If


            
'
该处记录日志信息，日志类型为操作异常



            myLogWrite.setLogType(
"
系统异常
"
)

            myLogWrite.setUserId(userStruc.userid)

            myLogWrite.setLogMachine()

            myLogWrite.setLogContent(
""
 
+
 escapeZifu(ex.Message, 
"
'
"
)) 
'
用户更改表 " + strTableName + " 中记录时发生异常：



            myLogWrite.insertLog()



            
Throw
 ex

        
End
 
Try


    
End Sub




    
'
该类为各功能模块提供删除数据的操作，参数为delete语句，和要删除的表



    
Public
 
Sub
 dataDelete(
ByVal
 strSql 
As
 
String
, 
ByVal
 strTableName 
As
 
String
)

        
Dim
 mysqlcomm 
As
 SqlClient.SqlCommand



        
Try


            sqlconn.Open()

            mysqlcomm 
=
 
New
 SqlClient.SqlCommand(strSql, sqlconn)

            mysqlcomm.ExecuteNonQuery()

            sqlconn.Close()

            mysqlcomm 
=
 
Nothing


            
'
该处记录日志信息，日志类型为：用户操作，用户内容包括insert语句，操作的表



            myLogWrite.setLogType(
"
用户操作
"
)

            myLogWrite.setUserId(userStruc.userid)

            myLogWrite.setLogMachine()

            myLogWrite.setLogContent(
"
用户删除表  
"
 
+
 strTableName 
+
 
"
中的记录
"
)

            myLogWrite.insertLog()

        
Catch
 ex 
As
 Exception

            
If
 sqlconn.State.Open 
=
 
1
 
Then


                sqlconn.Close()

            
End
 
If


            
'
该处记录日志信息，日志类型为操作异常



            myLogWrite.setLogType(
"
系统异常
"
)

            myLogWrite.setUserId(userStruc.userid)

            myLogWrite.setLogMachine()

            myLogWrite.setLogContent(
""
 
+
 escapeZifu(ex.Message, 
"
'
"
)) 
'
用户删除表 " + strTableName + " 中记录时发生异常：



            myLogWrite.insertLog()

            
Throw
 ex

        
End
 
Try


    
End Sub


    
'
该函数目的去掉字符串中的符号



    
Public
 
Function
 escapeZifu(
ByVal
 
str
 
As
 
String
, 
ByVal
 zifu 
As
 
String
) 
As
 
String


        
Dim
 istart 
As
 Int32

        istart 
=
 
str
.Trim.IndexOf(zifu)

        
While
 istart 
<>
 
-
1


            
str
 
=
 
str
.Substring(
0
, istart) 
+
 
str
.Substring(istart 
+
 
1
, 
str
.Length 
-
 istart 
-
 
1
)

            istart 
=
 
str
.IndexOf(zifu)

        
End
 
While


        
Return
 
str


    
End Function



End Class






四 调用方法



自己构造sql语句，和相关的表名



通过参数传递进去即可，这样将大大减少数据库操作方面的工作量。