最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。
Recordset object ¶
ADO Recordset object is used to hold a recordset from a database table.one Recordset the object consists of records and columns (fields).
In ADO, this object is the most important and most commonly used object to manipulate the data of the database. When you first open a In ADO, different cursor (pointer) types in 4 are defined: Dynamic cursor-allows you to view additions, changes, and deletions made by other users Keyset cursors-similar to dynamic cursors, except that you cannot view additions made by other users, and it prevents you from accessing records that have been deleted by other users. Data changes made by other users are still visible. Static cursor-provides a static copy of the recordset that can be used to find data or generate reports. In addition, additions, changes, and deletions made by other users will not be visible. When you open a client Forward cursor only-only allowed in Can be passed through Note: not all providers supports ProgID ¶
set objRecordset=Server.CreateObject("ADODB.recordset")
Recordset , the current record pointer points to the first record, while BOF and EOF the property is False . If there is no record, the BOF and EOF properties are True . Recordset object can support two types of updates: Recordset object, this is the only cursor type that is allowed. Recordset scroll forward in the. Inaddition, additions, changes, and deletions made by other users will not bevisible. CursorType property or Open in the method CursorType parameter to set the type of cursor. Recordset all methods and properties of the.
Attribute ¶
Attribute | Description |
|---|---|
| Sets or returns a specified |
| Sets or returns a value that specifies |
| Return and |
| If the connection is closed, set or return the definition of the connection,and if the connection is open, set or return the current |
| If the current record location is before the first record, return |
| Sets or returns a bookmark. The location where this bookmark saves the current record. |
| Sets or returns the number of records that can be cached. |
| Sets or returns the location of the cursor service. |
| Set or return the cursor type of a |
| Set or return the name of the data member to be retrieved from the object referenced by the |
| Specify an object that contains data to be represented as a |
| Returns the editing status of the current record. |
| If the location of the current record is after the last record, return |
| Returns a target for |
| Set or return |
| Set or return when editing |
| Sets or returns a value that specifies which records are returned to the server. |
| Sets or returns the return from a query |
| Returns the number of data pages in a |
| Set or return |
| Returns a |
| Sets or returns one or more as |
| Set a string value, or a |
| Returns a value that describes whether |
| Returns the status of the current record about batch updates or other numerous operations. |
| Sets or returns whether the reference to the child record changes when the location of the parent record changes. |
Method ¶
Method | Description |
|---|---|
| Create a new record. |
| Revoke an execution. |
| Undo a batch update. |
| Undo the right |
| Create a copy of the existing |
| Close |
| Compare the two bookmarks. |
| Delete a record or group of records. |
| Search for a record in a |
| Change multiple records from one |
| Set |
| In |
| Move the record pointer to the first record. |
| Move the record pointer to the last record. |
| Move the record pointer to the next record. |
| Move the record pointer to the previous record. |
| Clear the current by executing a series of commands |
| Open a database element that provides access to table records, query results, or saved ‘Recordset’. |
| Update by re-executing the query on which the object is based |
| Refresh the current from the original database |
| Put |
| Search |
| Returns a Boolean value that defines |
| Save all changes made to a single record in the Recordset object. |
| Save all changes in the |
Event ¶
Note: you cannot use VBScript or JScript processing (only Visual Basic, Visual blocking, and Visual Junction + languages are allowed to handle events).
Event | Description |
|---|---|
| Triggered when attempting to move to a line beyond the end of |
| Triggered when all records in the asynchronous operation are read. |
| It is triggered periodically during an asynchronous operation to report how many records have been read. |
| The value change of the `` Field` object is triggered. |
|
|
| A record is triggered after a change. |
| Triggered after the |
| Triggered before the value of the |
| Triggered before a record changes. |
| Triggered before making changes to the |
| Triggered before the current position in the |
Set ¶
Set | Description |
|---|---|
| Indicates the number of |
| Contains all |
Properties of the Fields collection ¶
Attribute | Description |
|---|---|
| Returns the number of items in the Example: countfields = rs.Fields.Count |
| Return Example: itemfields = rs.Fields.Item(1) 或者 itemfields = rs.Fields.Item("Name") |
Properties of the Properties collection ¶
Attribute | Description |
|---|---|
| Returns the number of items in the Example: countprop = rs.Properties.Count Item(named_item/number) 返回 properties 集合中某个指定的项目。 |
| Returns a specified item in the itemprop = rs.Properties.Item(1) 或者 itemprop = rs.Properties.Item("Name") |