Phương pháp thực thi ADO
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Phương thức Execute thực thi truy vấn, câu lệnh SQL hoặc thủ tục được chỉ định trong thuộc tính CommandText của đối tượng Command.
Kết quả được lưu trữ trong một đối tượng Recordset mới nếu nó là một truy vấn trả về hàng. Một đối tượng Recordset đã đóng sẽ được trả về nếu nó không phải là một truy vấn trả về hàng.
Cú pháp trả về hàng
Set rs=objcommand.Execute(ra,parameters,options)
Cú pháp không trả về hàng
objcommand.Execute ra,parameters,options
| Parameter | Description |
|---|---|
| ra | Optional. Returns the number of records affected by a query. For a row-returning query, use the RecordCount property of the Recordset object to count of how many records are in the object. |
| parameters | Optional. Parameter values passed with an SQL statement. Used to change, update, or insert new parameter values into the Parameters Collection. |
| options | Optional. Sets how the provider should evaluate the CommandText property. Can be one or more CommandTypeEnum or ExecuteOptionEnum values. Default is adCmdUnspecified. |
Thí dụ
<%
Set objcommand.CommandText="SELECT * FROM Customers"
objCommand.Execute
%>
or
<%
Set objcommand.CommandText="Customers"
objCommand.Execute(,,adCmdTableDirect)
%>
Giá trị CommandTypeEnum
| Constant | Value | Description |
|---|---|---|
| adCmdUnspecified | -1 | Does not specify the command type argument. |
| adCmdText | 1 | Evaluates CommandText as a textual definition of a command or stored procedure call. |
| adCmdTable | 2 | Evaluates CommandText as a table name whose columns are all returned by an internally generated SQL query. |
| adCmdStoredProc | 4 | Evaluates CommandText as a stored procedure name. |
| adCmdUnknown | 8 | Indicates that the type of command in the CommandText property is not known. |
| adCmdFile | 256 | Evaluates CommandText as the file name of a persistently stored Recordset. Used with Recordset.Open or Requery only. |
| adCmdTableDirect | 512 | Evaluates CommandText as a table name whose columns are all returned. Used with Recordset.Open or Requery only. To use the Seek method, the Recordset must be opened with adCmdTableDirect. This value cannot be combined with the ExecuteOptionEnum value adAsyncExecute. |
Giá trị ExecuteOptionEnum
| Constant | Value | Description |
|---|---|---|
| adOptionUnspecified | -1 | Indicates that the command is unspecified. |
| adAsyncExecute | Indicates that the command should execute asynchronously. This value cannot be combined with the CommandTypeEnum value adCmdTableDirect. | |
| adAsyncFetch | Indicates that the remaining rows after the initial quantity specified in the CacheSize property should be retrieved asynchronously. | |
| adAsyncFetchNonBlocking | Indicates that the main thread never blocks while retrieving. If the requested row has not been retrieved, the current row automatically moves to the end of the file. If you open a Recordset from a Stream containing a persistently stored Recordset, adAsyncFetchNonBlocking will not have an effect; the operation will be synchronous and blocking. adAsynchFetchNonBlocking has no effect when the adCmdTableDirect option is used to open the Recordset. | |
| adExecuteNoRecords | Indicates that the command text is a command or stored procedure that does not return rows (for example, a command that only inserts data). If any rows are retrieved, they are discarded and not returned. adExecuteNoRecords can only be passed as an optional parameter to the Command or Connection Execute method. | |
| adExecuteStream | Indicates that the results of a command execution should be returned as a stream. adExecuteStream can only be passed as an optional parameter to the Command Execute method. | |
| adExecuteRecord | Indicates that the CommandText is a command or stored procedure that returns a single row which should be returned as a Record object. |
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