طريقة ADO CreateParameter
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تقوم طريقة CreateParameter بإنشاء وإرجاع كائن معلمة يحتوي على الخصائص المحددة مثل الاسم والنوع والاتجاه والحجم والقيمة.
ملاحظة: لا تضيف هذه الطريقة المعامل الجديد تلقائيًا إلى المجموعة. لإضافة المعلمة إلى مجموعة المعلمات ، استخدم خاصية إلحاق.
بناء الجملة
Set objparameter=objcommand.CreateParameter
(name,type,direction,size,value)
| Parameter | Description |
|---|---|
| name | Optional. The name of the Parameter object. |
| type | Optional. One of the DataTypeEnum constants that specifies the data type for the Parameter object. Default is adEmpty. If you choose a variable-length data type, you will also need to specify the Size parameter or the Size property. If you specify adDecimal or adNumeric data type, you must also set the NumericScale and the Precision properties of the Parameter object. |
| direction | Optional. One of the ParameterDirectionEnum constants that defines the direction of the Parameter object. Default is adParamInput. |
| size | Optional. Specifies the length of a variable-length data type, if such a type was declared in the Type parameter. Default is zero. |
| value | Optional. The value of the Parameter object |
قيم DataTypeEnum
يحدد نوع البيانات لكائن حقل أو معلمة أو خاصية
| Constant | Value | Description |
|---|---|---|
| adEmpty | 0 | No value |
| adSmallInt | 2 | A 2-byte signed integer. |
| adInteger | 3 | A 4-byte signed integer. |
| adSingle | 4 | A single-precision floating-point value. |
| adDouble | 5 | A double-precision floating-point value. |
| adCurrency | 6 | A currency value |
| adDate | 7 | The number of days since December 30, 1899 + the fraction of a day. |
| adBSTR | 8 | A null-terminated character string. |
| adIDispatch | 9 | A pointer to an IDispatch interface on a COM object. Note: Currently not supported by ADO. |
| adError | 10 | A 32-bit error code |
| adBoolean | 11 | A boolean value. |
| adVariant | 12 | An Automation Variant. Note: Currently not supported by ADO. |
| adIUnknown | 13 | A pointer to an IUnknown interface on a COM object. Note: Currently not supported by ADO. |
| adDecimal | 14 | An exact numeric value with a fixed precision and scale. |
| adTinyInt | 16 | A 1-byte signed integer. |
| adUnsignedTinyInt | 17 | A 1-byte unsigned integer. |
| adUnsignedSmallInt | 18 | A 2-byte unsigned integer. |
| adUnsignedInt | 19 | A 4-byte unsigned integer. |
| adBigInt | 20 | An 8-byte signed integer. |
| adUnsignedBigInt | 21 | An 8-byte unsigned integer. |
| adFileTime | 64 | The number of 100-nanosecond intervals since January 1,1601 |
| adGUID | 72 | A globally unique identifier (GUID) |
| adBinary | 128 | A binary value. |
| adChar | 129 | A string value. |
| adWChar | 130 | A null-terminated Unicode character string. |
| adNumeric | 131 | An exact numeric value with a fixed precision and scale. |
| adUserDefined | 132 | A user-defined variable. |
| adDBDate | 133 | A date value (yyyymmdd). |
| adDBTime | 134 | A time value (hhmmss). |
| adDBTimeStamp | 135 | A date/time stamp (yyyymmddhhmmss plus a fraction in billionths). |
| adChapter | 136 | A 4-byte chapter value that identifies rows in a child rowset |
| adPropVariant | 138 | An Automation PROPVARIANT. |
| adVarNumeric | 139 | A numeric value (Parameter object only). |
| adVarChar | 200 | A string value (Parameter object only). |
| adLongVarChar | 201 | A long string value. |
| adVarWChar | 202 | A null-terminated Unicode character string. |
| adLongVarWChar | 203 | A long null-terminated Unicode string value. |
| adVarBinary | 204 | A binary value (Parameter object only). |
| adLongVarBinary | 205 | A long binary value. |
| AdArray | 0x2000 | A flag value combined with another data type constant. Indicates an array of that other data type. |
ParameterDirectionEnum القيم
يحدد ما إذا كانت المعلمة تمثل معلمة إدخال ، أو معلمة إخراج ، أو معلمة إدخال ومخرجات ، أو قيمة الإرجاع من إجراء مخزن.
| Constant | Value | Description |
|---|---|---|
| adParamUnknown | 0 | Direction is unknown |
| adParamInput | 1 | Input parameter |
| adParamOutput | 2 | Output parameter |
| adParamInputOutput | 3 | Both input and output parameter |
| adParamReturnValue | 4 | Return value |
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