20 ASP items that beginners should remember

Author：Eve Cole Update Time：2025-02-23 10:48:02

1. How to use ASP to determine the virtual physical path of your website

Answer: Use the Mappath method

The Physical path to this virtual website is:

< %= Server.MapPath(/)% >

2. How do I know the browser the user is using?

Answer: Use the Request object method

strBrowser=Request.ServerVariables(HTTP_USER_AGENT)

If Instr(strBrowser,MSIE) < > 0 Then

Response.redirect(ForMSIEOnly.htm)

Else

Response.redirect(ForAll.htm)

End If

3. How to calculate the average number of repeat visitors per day

Answer: Solution

< % startdate=DateDiff(d,Now,01/01/1990)

if strdate< 0 then startdate=startdate*-1

avgvpd=Int((usercnt)/startdate) % >

Show results

< % response.write(avgvpd) % >

that is it.this page has been viewed since November 10,1998

4. How to display random images

< % dim p,ppic,dpic

ppic=12

randomize

p=Int((ppic*rnd)+1)

dpic=graphix/randompics/&p&.gif

show

< img src=< %=dpic% > >

5.How to return to the previous page

Answer: < a href=< %=request.serverVariables(Http_REFERER)% > >preivous page< /a >

Or use a picture such as: < img src=arrowback.gif target='_blank'> If the server is running, if a dialog box can be displayed on the server, then you have to wait until someone clicks OK before your program can continue to execute. Generally, The server will not be guarded, so Microsoft has to ban this function and randomly tell you (:) haha) that you have no permission. However, the combination of ASP and client script can display a dialog box, as follows:

< % yourVar=Test Dialog % >

< % script language='javascript' >

alert(< %=yourvar% >)

</script>

11. Is there any way to protect your source code from being seen by others?

Answer: You can download a Microsoft Windows Script Encoder, which can encrypt asp scripts and client-side javascript/vbscript scripts. . . However, after the client is encrypted, only ie5 can execute it. After the server-side script is encrypted, it can only be executed if script engine 5 is installed on the server (just install an ie5).

12.How can I transfer query string from one asp file to another?

Answer: Add the following sentence to the former file: Response.Redirect(second.asp? & Request.ServerVariables(QUERY_STRING))

13.global.asa file always doesn’t work?

Answer: Global.asa is only valid if the web directory is set to web application, and global.asa is valid in the root directory of a web application. IIS4 can use Internet Service Manager to set application settings. How can I make the htm file execute script code like an asp file?

14. How can I make the htm file to execute script code like the asp file?

Answer: Internet Services Manager -> select default web site -> right mouse button -> menu properties -> home directory -> application settings (Application Setting) -> click button configuration -> app mapping -> click button Add -> executable Browse select /WINNT YSTEM32/INETSRV/ASP.DLL EXTENSION, enter htm method exclusions, enter PUT.DELETE, and confirm everything. However, it is worth noting that the htm will also be processed by asp.dll, and the efficiency will be reduced.

15.How to register components

Answer: There are two methods.

The first method: Manually register the DLL. This method has been used from IIs 3.0 to IIs 4.0 and other Web Servers. It requires you to execute it from the command line, enter the directory containing the DLL, and enter: regsvr32 component_name.dll, for example, c:/temp egsvr32 AspEmail.dll. It will register the specific information of the dll into the registry on the server. The component can then be used on the server, but there is a flaw in this approach. After the component is registered using this method, the component must set the NT anonymous account accordingly to have permission to execute the dll. In particular, some components need to read the registry, so this method of registering components is only used when there is no MTS on the server. To unregister the dll, use: regsvr32 /u aspobject.dll example c:/temp egsvr32 / uaneiodbc.dll

Second method: Use MTS (Microsoft Transaction Server) MTS is a new feature of IIS 4, but it provides huge improvements. MTS allows you to specify that only privileged users can access components, greatly improving the security settings on the website server. The steps to register a component on MTS are as follows:

1) Open the IIS management console.

2) Expand transaction server, right-click pkgs installed and select new package.

3) Click create an empty package.

4) Name the package.

5) Specify the administrator account or use interactive (if the server is often logged in using the administrator).

6) Now right-click on the expanded components under the package you just created. Select new then component.

7) Select install new component [b].

8) Find your .dll file and select next to finish.

To delete this object, just select its icon and then select delete.

Note: Pay special attention to the second method, it is the best way to debug the components you write without having to restart the machine every time.

16. ASP and Access database connection:

17. ASP and SQL database connection:

Create a recordset object:

set rs=server.createobject(adodb.recordset)

rs.open SQL statement,conn,3,2

18. How to use common SQL commands:

(1) Data record screening:

sql=select * from data table where field name = field value order by field name [desc]

sql=select * from data table where field name like '%field value%' order by field name [desc]

sql=select top 10 * from data table where field name order by field name [desc]

sql=select * from data table where field name in ('value 1', 'value 2', 'value 3')

sql=select * from data table where field name between value 1 and value 2

(2) Update data record:

sql=update data table set field name=field value where conditional expression

sql=update data table set field 1=value 1, field 2=value 2...field n=value n where conditional expression

(3) Delete data records:

sql=delete from data table where conditional expression

sql=delete from data table (delete all records in the data table)

(4) Add data record:

sql=insert into data table (field 1, field 2, field 3...) values (value 1, value 2, value 3...)

sql=insert into target data table select * from source data table (add records from the source data table to the target data table)

(5) Data recording statistical function:

AVG(field name) derives a table column average

COUNT(*|field name) counts the number of data rows or counts the number of data rows with a value in a certain column

MAX (field name) gets the maximum value of a table column

MIN (field name) gets the minimum value of a table column

SUM (field name) adds the values of the data columns

How to reference the above function:

sql=select sum(field name) as alias from data table where conditional expression

set rs=conn.excute(sql)

Use rs (alias) to obtain statistical values, and use the same methods as above for other functions.

(5) Creation and deletion of data tables:

CREATE TABLE data table name (field 1 type 1 (length), field 2 type 2 (length)...)

Example: CREATE TABLE tab01(name varchar(50),datetime default now())

DROP TABLE data table name (permanently delete a data table)

19. Methods of recordset object:

rs.movenext moves the record pointer down one line from the current position

rs.moveprevious moves the record pointer up one line from the current position

rs.movefirst moves the record pointer to the first row of the data table

rs.movelast moves the record pointer to the last row of the data table

rs.absoluteposition=N moves the record pointer to row N of the data table

rs.absolutepage=N moves the record pointer to the first row of page N

rs.pagesize=N sets each page to N records

rs.pagecount returns the total number of pages according to the settings of pagesize

rs.recordcount returns the total number of records

rs.bof returns whether the record pointer exceeds the beginning of the data table, true means yes, false means no

rs.eof returns whether the record pointer exceeds the end of the data table, true means yes, false means no

rs.delete deletes the current record, but the record pointer does not move downwards

rs.addnew adds records to the end of the data table

rs.update updates data table records

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20 Recordset object methods

Open method

recordset.Open Source,ActiveConnection,CursorType,LockType,Options

Source

The Recordset object can be connected to the Command object through the Source property. The Source parameter can be a Command object name, a SQL command, a specified data table name or a Stored Procedure. If this parameter is omitted, the system uses the Source property of the Recordset object.

ActiveConnection

Recordset objects can connect to Connection objects through the ActiveConnection property. The ActiveConnection here can be a Connection object or a string of string parameters containing database connection information (ConnectionString).

CursorType

The CursorType parameter of the Open method of the Recordset object indicates what type of cursor the data will be started with, including adOpenForwardOnly, adOpenKeyset, adOpenDynamic and adOpenStatic, as described below:

-------------------------------------------------- ----------

Constant value description

-------------------------------------------------- ----------

adOpenForwardOnly 0 Default value, starts a cursor that can only move forward (Forward Only).

adOpenKeyset 1 starts a Keyset type cursor.

adOpenDynamic 2 starts a Dynamic type cursor.

adOpenStatic 3 starts a Static type cursor.

-------------------------------------------------- ----------

The above cursor types will directly affect all properties and methods of the Recordset object. The following list illustrates the differences between them.

-------------------------------------------------- ----------

Recordset properties adOpenForwardOnly adOpenKeyset adOpenDynamic adOpenStatic

-------------------------------------------------- ----------

AbsolutePage does not support reading and writing.

AbsolutePosition is not supported. Not supported. Readable and writable. Readable and writable.

ActiveConnection read-write read-write read-write read-write

BOF read only read only read only read only

Bookmark is not supported. It is not supported. It can be read and written. It can be read and written.

CacheSize Readable and writable Readable and writable Readable and writable Readable and writable

CursorLocation Readable and writable Readable and writable Readable and writable Readable and writable

CursorType Read and write Read and write Read and write Read and write

EditMode read-only read-only read-only read-only

EOF read only read only read only read only

Filter Readable and writable Readable and writable Readable and writable Readable and writable

LockType Read and write Read and write Read and write Read and write

MarshalOptions Readable and writable Readable and writable Readable and writable Readable and writable

MaxRecords Readable and writable Readable and writable Readable and writable Readable and writable

PageCount does not support read-only read-only

PageSize Readable and writable Readable and writable Readable and writable Readable and writable

RecordCount does not support read-only read-only

Source Readable and writable Readable and writable Readable and writable Readable and writable

State read only read only read only read only

Status read only read only read only read only

AddNew Support Support Support Support

CancelBatch support support support support

CancelUpdate support support support support

Clone is not supported. Not supported.

Close support support support support

Delete support support support support

GetRows support support support support

Move is not supported, supported, supported.

MoveFirst support support support support

MoveLast not supported supported supported supported

MoveNext support support support support

MovePrevious Not supportedSupportedSupported

NextRecordset support support support support

Open support support support support

Requery support support support support

Resync Not supported Not supported Supported Supported

Supports

Update Support Support Support Support

UpdateBatch support support support support

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The NextRecordset method does not apply to Microsoft Access databases.

LockType

The LockType parameter of the Open method of the Recordset object indicates the Lock type to be used. If this parameter is ignored, the system will use the LockType property of the Recordset object as the default value. LockType parameters include adLockReadOnly, adLockPrssimistic, adLockOptimistic and adLockBatchOptimistic, etc., which are described as follows:

-------------------------------------------------- ----------

Constant constant value description

-------------------------------------------------- ----------

adLockReadOnly 1 Default value, Recordset object starts in read-only mode, cannot run AddNew, Update, Delete and other methods

adLockPrssimistic 2 When the data source is being updated, the system will temporarily lock other users' actions to maintain data consistency.

adLockOptimistic 3 When the data source is being updated, the system will not lock other users' actions, and other users can add, delete, and modify data.

adLockBatchOptimistic 4 When the data source is being updated, other users must change the CursorLocation attribute to adUdeClientBatch to add, delete, or modify data.