VB和数据库

操作MySQL数据库方法1.连接数据库1)下载Connector/Net:/downloads/connector/net/2)安装Connector/Net.3)在工程中，选择Project->Add Reference…菜单，添加MySQl.data 引用，如下图所示：4)在需要连接数据的文件中添加一行，以打开namespace：Imports MySql.data.MySqlClient5)创建一个数据库连接m_strConnection ="server=127.0.0.1;uid=root;pwd=12345;database=computer; pooling=false"m_SqlConn = New MySqlConnection(m_strConnection)2.显示数据1)创建一个数据库适配器Dim strQuery As String = "select * from Product"Dim daAdapter As MySqlDataAdapter = New MySqlDataAdapter(strQuery, m_SqlConn)2)创建一个Datatable，用数据库适配器来填充datatableDim dsTable As DataTable = New DataTable(strDataset)daAdapter.Fill(dsTable)3)绑定datatable到DataGrid控件dbGridShow.SetDataBinding(dsTable, "")dbGridShow.Visible = True3.获取表中的某一行某一列‘获得指定行Dim CurRow As IntegerCurRow = dbGridShow.CurrentRowIndexDim tbl As DataTable = dbGridShow.DataSourceDim Row As DataRow = tbl.DefaultView(CurRow).Row'根据当前选定的行得到Delete操作的SQL语句Dim strDelete As StringstrDelete = "delete from T_Bars where name = '" + Row("name") + "'"4.修改或删除数据'定义操作的SQL语句Dim strSql As StringstrSql = "insert into Product(maker,model,type) values('"…”)'创建SqlCommand对象Dim myCommand As MySqlCommand = New MySqlCommand(strInsertCommand, m_SqlConn) ‘执行操作m_SqlConn.Open()nRows = myCommand.ExecuteNonQuery()。

如何设置对vb数据库连接的动态路径_visualbasic教程西部数码-全国虚拟主机10强！20余项虚拟主机管理功能,全国领先!第6代双线路虚拟主机,南北访问畅通无阻!虚拟主机可在线rar解压,自动数据恢复设置虚拟目录等.虚拟主机免费赠送访问统计,企业邮局.Cn域名注册10元/年,自助建站480元起,免费试用7天,满意再付款!P4主机租用799元/月.月付免压金!我个人因为经常作一些数据库方面的程序，对于程序间如何与数据库进行接口的问题之烦是深有体会，因为VB 在数据库链接的时候，一般是静态，即数据库存放的路径是固定的，如用VB的DATA，adodc,DataEnvironment 等到作数据库链接时，如果存放数据库的路径被改变的话，就会找不到路经，真是一个特别烦的事。

笔者的解决方法是利用app.path来解决这个问题。

一、用data控件进行数据库链接，可以这样：在form_load()过程中放入：privateform_load()DimstrAsString定义str=App.PathIfRight(str,1)<>"\"Thenstr=str "\"EndIfdata1.databasename=str&"\数据库名"data1.recordsource="数据表名"data1.refreshsubend这几句话的意为，打开当前程序运行的目录下的数据库。

你只要保证你的数据库在你程序所在的目录之下就行了。

二、利用adodc（ADODataControl)进行数据库链接：privateform_load()DimstrAsString定义str=App.PathIfRight(str,1)<>"\"Thenstr=str "\"EndIfstr="Provider=Microsoft.Jet.OLEDB.3.51;PersistSecurityInf o=False;DataSource="&str&"\tsl.mdb"Adodc1.ConnectionString=strmandType=adCmdTextAdodc1.RecordSource="select*fromtable3"Adodc1.Refreshendsub三、利用DataEnvironment进行数据库链接可在过程中放入：OnErrorResumeNextIfDataEnvironment1.rsCommand1.State<>adStateClosedTh enDataEnvironment1.rsCommand1.Close如果打开，则关闭EndIfi=InputBox("请输入友人编号:","输入")Ifi=""ThenExitSubDataEnvironment1.Connection1.OpenApp.Path&"\userdata base\tsl.mdb"DataEnvironment1.rsCommand1.Open"select*fromtable3wh ere编号="&i&""SetDataReport2.DataSource=DataEnvironment1 DataReport2.DataMember="command1"DataReport2.showendsub四、利用ADO(ActiveXDataObjects)进行编程：建立连接：dimconnasnewadodb.connection dimrsasnewadodb.recordsetdimstrstr=App.PathIfRight(str,1)<>"\"Thenstr=str "\"EndIfstr="Provider=Microsoft.Jet.OLEDB.3.51;PersistSecurityInf o=False;DataSource="&str&"\tsl.mdb"conn.openstrrs.cursorlocation=aduseclientrs.open"数据表名",conn,adopenkeyset.adlockpessimistic用完之后关闭数据库：conn.closesetconn=nothing以上代码在VB6，win98上运行通过，如有问题请发邮件给我：作者：张振兴E_mail:xingyun0615@->文章整理：西部数码--专业提供域名注册、虚拟主机服务以上信息与文章正文是不可分割的一部分,如果您要转载本文章,请保留以上信息，谢谢!VB数据库连接技巧-精华（2008-11-19 17:17:00）DAO数据约束控件和RecordSet数据约束控件是指要求与Data 控件连接到一起的控件，如DBGird 等。

VB使用ADODB操作数据库的常用方法ADO常用方法下面是我所掌握的使用ADO对数据库操作的一些常用方法,主要是提供给初学者作为参考,有不对的地方请指正.如有补充不胜荣幸准备工作========Dim conn As New ADODB。

Connection ’创建一个Connection 实例，在这里使用New等于将Dim和Set合并为一段代码执行Dim rs As ADODB。

Recordset ’创建一个Recordset 实例，不使用New 是因为,经常需要重复使用Set,因此没必要在这里使用Dim CnStr As String，Sql As String’创建两个字符串变量分别存放两个集合的SQL语句代码段1、装载数据库（不属于Recordset集合）=============Dim FileNamw$，DbIp$，DbName＄, DbUser$，DbPw$'以上5个字符串变量分别表示文件路径和文件名、数据库地址、数据库名、数据操作员用户名、操作员密码FileName = App。

Path & "\’数据库名'”DbIp = ”数据库地址"DbName = ”数据库名"DbUser = "数据操作员用户名”DbPw = "操作员密码”'以上变量根据数据库类型的不同而不同，有可能只需要1至两个变量’1）连接Access数据库：'-—-----——-——-——-—--CnStr = "PROVIDER=microsoft。

jet.oledb。

3.51；persist security info =false；data source="& FileName & ”；Jet OLEDB:Database Password="＆DbPw’2)连接Oracle数据库:'--—-—---—-——-——-——-CnStr = "PROVIDER=MSDAORA。

附录VB And Database1 VB Database Access MethodVB database visit many ways, under normal circumstances is divided into two categories, and each category there are many ways. Below in tabular form for each of the categories, and each category contains methods.1.1Object Interface (API)VBSQL : through DB-Library visit the Microsoft SQL Server ODBC API : any ODBC data source 16 and 32 DAO / Jet : Jet local / Access.MDB. Index sequence database (ISAM) and any ODBC data source DAO / ODBC Direct : any ODBC data source (after RDO) RDO 2.0 : any ODBC data source (Level I or II) ADO : any ODBC data source and any OLE DB interface through the data source interface1.2Data Control ActData Control : DAO / Jet Data Interface Control Data Interface / Direct ODBC : DAO / ODBC data interface Direct Control Interface RemoteData / RD C : RDO data interface Advanced Data Interface Connector / ADC : ADO data interface Interface2 Several of InterfaceADC (Advanced Data Connector) : Advanced Data Connector. ADO provide bundled data source window to the data binding controls on. ADC is essentially a visit or through direct access remote ADO OLE DB object of a technology, It also supports major applications in the Microsoft IE browser bundled with the data control. It is specifically for the Web browser-based application designed.ADO (Active Data Objects) : Active Data Objects. Yes DAO / RDO the successor product, ADO "expansion" of the DAO and RDO used by the object model, This means that it contains fewer targets, more attributes, methods (parameters), and the incident. ADO is a real visit with the various types of data linking mechanism. ADO designed for a very simple format, through the ODBC interface with the database. Can use any ODBC data source, that is not suitable for SQL Server, Oracle, Access such as database applications, but also for Excel spreadsheets, text files, No graphics files and the data file format is an easy-to-use application program interface layer. ADO isMicrosoft's latest and most powerful data access model designed OLE DB, for any OLE DB data source to provide a high-performance interviews, including data sources and non-relational databases, E-mail and file systems, text and graphics, custom business objects, and so on. ADO in key Internet program for at least the network traffic, and the front-end data sources and the use of at least between the layers, all of which are meant to provide light volume, high-performance interface. So ADO through its internal attributes and methods of providing unified data access interface method.DAO (Data Access Objects) : data access object. Is an object-oriented inte rface to the interface. Through DAO / Jet functi on can access ISAM database, use DAO / ODBC Direct functions can be remote RDO function. DAO use the program code is very simpl e. DAO provide rich cursor (Cursor) type and the result of non-cursor (Cursor-Less) type of res ult sets, with the DDL (data description language) is ver y similar to the function. DAO through ODBC, as a direct link to other databases. connect directly to the Access database. DAO sy stem suitable for single applications or small - scale use of the local distribution. DAO model is to design relational database system archit ecture object class collection. They provide a complete management system for the entire oper.html ation of the properties and methods. including the creation of the database, definition of the tables, the fields and indexes, the establishment of the relationship between the tables, positioning and searching tools such as databa ses.JET (Joint Engine Technology) : data connectivity engine technologies. A workstation is based on the adoption of DAO database access mechanism. Although Microsoft Access can be provided by the ODBC driver visit Jet database However, the use of these drivers functional restrictions. Jet has its own mechanism for the inquiry and the result set handling, and can be the same species or dissimilar data sources for query processing.0DBC (Open Database Connectivity) : open database connectivity. Heterogeneous database for the visit provides a unified interface. ODBC based on SQL (Structured Query Language), and regarded it as the standard database. This interface provides maximum interoperability : an application program through a group of generic code access different database management systems. A software developer in the development of client / server applications will not be binding on a particular database above. ODBC for different database for a corresponding driver, is a recognized source of the data Interface. It fast and light to provide a unified interface and the interface to any ODBC data source optimized for neither.ODBC API : manufacturers to the database designer procedures provide direct access to the database of a group function. Note : The point here is that although the ODBC API provides a lot of convenience and powerful functionality. But usually the ODBC API are relatively hard to learn, but it is very prone to error. Although ODBC API allowed to operate ODBC handle, but they still have to be careful If incorrect use ODBC API, it may result in unpredictable error. For example, if the use of ODBC API code to close the connection or ODBC release handle of any one, Then RemoteData control or RDO behavior will be unpredictable. ODBC handle depositary for the reserve is meaningless, because they are variable.ODBC Direct : DAO is a target based on the new DAO mode its methods and attributes and RDO function the same. Use the DAO code of occasions, can be used to access remote data sources.OLE DB : COM model is the database interface. The bottom is a data access interface interface. Is the third driver for the development of businesses exporting data sources to ADO applications, or for C + + developers development of customized database components. It will be able to handle any type of data. OLE DB application to provide a uniform data access methods, without considering their format and storage. In practical application, which means you can visit diversity presence in the electronic data sheets, text files and even mail server Microsoft Exchang such as the data. OLE DB was not directly call VB.RDC (RemoteData Control) : Remote Data Access Control. RDO right is a bundled component data. Can output the result of specific data sources to control.RDO (Remote Data Objects) : Remote Data Objects. ODBC is one of the object-oriented data access interface, Remote data objects and code sets for use to create and operate a remote ODBC database system for the various components a framework. Set targets and have a database describing the characteristics of the various components used to manipulate the attributes and methods of these components. Can set targets and establish relations between these relations on behalf of the database system, the logical structure. It's easy to use the same style DAO combination provides an interface, ODBC form displayed all the bottom function and flexibility. RDO ODBC API is a shallow interfacing. Is designed to access remote data sources ODBC relations and design. Although the visit RDO Jet or ISAM database is restricted, but it can only work through the existing ODBC driver to access the relational database. However, the RDO has been proved to be many SQL Server, Oracle and other major database developers often choose the best interface. RDO provided to access storedprocedures and complex set of results more and more complex objects, attributes and methods.VBSQL : Visual Basic is structured query language. An API is the interface, almost C DB-Library API the same. VBSQL only support Microsoft's SQL Server. VBSQL fast and light but not for the target interface.3Performance Comparison and Application NoteVB-based SQL Server database system Several visits over the SQL Server specific features. DAOs is based on the object, so it is easy to use, However it from Visual Basic to SQL Server slowest way. ODBC API and VBSQL method is essentially based on the procedures. ODBC API method is common, allow the strongest interoperability, a simple programming, However, the slow pace in VBSQL methods. VBSQL VBSQL Control Methods, provided an important SQL Server front-end applications needed flexibility, strong functions and good performance. It is truly event-driven and error handling capability, fully supports asynchronous processing, and pointing out such calculations. These methods are VBSQL other methods beyond the edge, but its slightly complex programming. RDO ODBC API is located at the top of a layer object model, which rely on ODBC API, ODBC driver and the back-end database engine to achieve. RDO used in the procedures necessary for the short (about 250 KB), fast. RDO equipped with the basic approach of ODBC, most direct enforcement ODBC API function, RDO 4.0/VB included in the VB 5.0 Enterprise Edition, MSRDO32.DLL by Dynamic Link Library is to be achieved. RDO is a synthesis of DAO / Jet, VBSQL / DBLib ODBC and the advantages of the object model, ODBC API includes application layer, designed for in the background (server side) have a database exists on the premise of running, against Oracle and SQL Server specially designed. RDO has the advantage of being fully integrated in VB, can directly access SQL Server stored procedures fully supports T-SQL, T-SQL debugging in the integrated development environment, Visual Database Tools integration, and so on. However, Microsoft has announced that in future no longer be right VBSQL / DBLib upgrade, ODBC API function and general programming method is loved by the people, RDO application will be reduced gradually. As for the actual use of any interface, to a large extent dependent on the user's application specific circumstances. 4VB database principleVB access to the database, it is necessary to analyze specific issues, according to the specific circumstances, conditions, request with the appropriate programs, it should pay attention to the following principles :4.1code reuse and efficiency of the operationFor example : through the use of ODBC data sources connecting to the database, we will be able to transform the various types of databases, instead frequent code changes. VBSQL used by DB-Library will not do. ODBC interface and VB database is not running the most efficient method. Similarly, the use of ADO ODBC interface to the efficiency than RDO.4.2achieve simplicity, ease of maintenanceIf a method to achieve together is very complex, the development will inevitably result in the waste of human and material resources. Moreover, the design application will only support up more complex or more difficult to maintain. For example : local needs ISAM or visit Jet types of data sources, the use of DAO / Jet, and it is not necessary to use the method through ODBC. RDC together to achieve more easily than the RDO.4.3safety principlesThis should be an environment and conditions. For example, the LAN network security better in the WAN thus directly control the use of data such as RDC, This realization together fast and convenient, and WAN needs of a large number of errors caught, As the RDC is not as good as using the wrong RDO easy to control.5Concluding remarksThe data access interface DAO system suitable for single applications or small-scale use of the local distribution, RDO which has been proved to be many SQL Server, Oracle and other major database developers often choose the best interface. ADO DAO / RDO the successor product. ADO 2.0 functional and RDO more similar, but generally speaking, In this model between the two species have a similar relationship mapping. ADO "expansion" of the DAO and RDO by the use of the object model, which means that it contains fewer targets, more attributes, methods and parameters, and the incident.Database Interface is the latest ADO, it is more than DAO and RDO more simple, more flexible object model. For new projects, it should be used as ADO data access interface.However, the ADO is not automatic, and the existing data access application code compatible. When ADO Packaging DAO and RDO the function of the need to change many of the elements of language syntax ADO. In some cases, this will mean that some of the existing code of a function of a simple conversion. In other cases, the best approach might be the use of new functional ADO rewriting the application. Also notethat the current ADO DAO does not support all the functions. ADO include RDO style functionality, and to OLE DB data source interaction, It also includes long-range, and DHTML technologies.Generally speaking, in ADO 1984, Most immediately put DAO application ADO transplant may be premature ADO because the current data do not support the definition (DDL), users, groups. However, if only DAO for client / server applications, and is not dependent on the Jet database engine or not to use DDL, then it could be transplanted to ADO.VB与数据库1 VB访问数据库的方法VB访问数据库的方法很多，一般情况下分成两大类，而每一类又有很多方法。

在专业的数据库软件开发中，为了确保数据库中信息的安全，往往要求对数据库文件进行加密，以防止非法用户通过其它的常规手段将其打开。

那么，在Visual Basic中如何建立与加密的数据库的连接呢？笔者在日常工作中，总结了一些方法和技巧，现写出来与同行们交流。

一、连接加密的Access数据库,假设要连接的数据库为hg.mdb，密码为“123”在Visual Basic 6.0中，要建立与数据库的连接，可采用的技术手段很多，如：数据控件、数据对象、数据环境设计器等。

1、使用控件① Data控件Data控件是Visual Basic 6.0中的一个内置数据控件，可以通过设置Data控件的connect、DatabaseName、RecordSource属性实现对数据库的连接和访问。

通过Data控件连接加密的数据库的方法有两种：一种方法是在设计状态时，在“属性窗口”中将Data控件的connect属性的缺省值”Access”改为”; pwd=123”即可，其它属性的设置方法与没有加密的Access数据库的连接相同。

另一种方法是在运行时，通过代码对connect属性赋值来实现。

如：Data1.connect=”; pwd=123”Data1.DatabaseName=APP.path + “\hg.mdb”其中，”123”为Access数据库文件hg.mdb的密码，下同。

②Adodc控件Adodc控件是一个ActiveX控件，它使用Microsoft ActiveX Data Objects(ADO)创建到数据库的连接。

使用Adodc控件之前，要先将Adodc控件添加到控件工具箱中。

方法如下：在VB 6.0种选择“工程”菜单，再点击“部件”菜单项，在弹出的“部件”对话框中选中“Microsoft ADO Data Control 6.0(OLEDB)”选项即可。

通过Adodc控件连接加密的数据库的方法也有两种：一种方法是在设计状态时，在“属性窗口”中，对Adodc控件的ConnectionString属性设置一个有效的连接字符串，并在连接字符串后增加上”; Jet OLEDB: DataBase password=123”，再设置Adodc控件的CommandType、RecordSource的属性就可以创建到加密的数据库的连接了。