Thuộc tính loại ADO
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Thuộc tính Type đặt hoặc trả về giá trị DataTypeEnum cho biết kiểu của một đối tượng Parameter, Field hoặc thuộc tính.
Object | Description of the Type Property |
---|---|
Parameter | The Type property has read/write permissions on a Parameter object |
Field | The Type property is read/write, with one exception; for new Field objects that are added to the Fields collection of a Record, this property is read-only before the Value property has been set and before the provider has called the Update method of the Fields collection |
Property | The Type property is read-only for a Property object |
Cú pháp
objectname.Type
Ví dụ - Đối với một đối tượng Trường
<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open "c:/webdata/northwind.mdb"
set rs = Server.CreateObject("ADODB.Recordset")
rs.open "Select * from orders", conn
response.write(rs.Fields(0).Type)
rs.Close
conn.close
%>
Ví dụ - Đối với một đối tượng Tham số
<%
set comm=Server.CreateObject("ADODB.Command")
set para=Server.CreateObject("ADODB.Parameter")
para.Type=adVarChar
para.Size=25
para.Direction=adParamInput
para.Value=varfname
comm.Parameters.Append para
%>
Ví dụ - Đối với một đối tượng Thuộc tính
<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open "c:/webdata/northwind.mdb"
set rs = Server.CreateObject("ADODB.Recordset")
rs.open "Select * from orders", conn
set prop=Server.CreateObject("ADODB.Property")
'Display the property attributes of the Orders Table
for each prop in rs.Properties
response.write("Attr:" & prop.Attributes & "<br>")
response.write("Name:" & prop.Name & "<br>")
response.write("Value:" & prop.Value & "<br>")
next
rs.close
conn.close
set rs=nothing
set conn=nothing
%>
Giá trị DataTypeEnum
Chỉ định kiểu dữ liệu của đối tượng Trường, Tham số hoặc Thuộc tính
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. |
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