Data.DB.TParam.GetDataSize
Delphi
function GetDataSize: Integer;
C++
int __fastcall GetDataSize();
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| function | public | Data.DB.pas Data.DB.hpp |
Data.DB | TParam |
Description
Returns the number of bytes needed to hold the parameter's value in the format used by the corresponding type of database field.
Call GetDataSize to determine the number of bytes used to represent the parameter's value. GetDataSize indicates the buffer size needed before calling the GetData method. The value returned by GetDataSize depends on the Value of the parameter. For some values of DataType, this is always the same:
| DataType | Value of DataSize |
|---|---|
|
ftBoolean |
2 |
|
ftSmallint |
2 |
|
ftWord |
2 |
|
ftAutoInc |
4 |
|
ftDate |
4 |
|
ftInteger |
4 |
|
ftTime |
4 |
|
ftCurrency |
8 |
|
ftDateTime |
8 |
|
ftFloat |
8 |
|
ftTimeStamp |
16 |
|
ftBCD |
34 |
|
ftString |
length of the string + 1 |
|
ftFixedChar |
length of the string + 1 |
|
ftVarBytes |
If the value is a Variant array, the number of elements in the array, else 0 |
|
ftBytes |
If the value is a Variant array, the number of elements in the array, else 0 |
|
ftBlob |
number of bytes of blob data |
|
ftFmtMemo |
number of bytes of blob data |
|
ftGraphic |
number of bytes of blob data |
|
ftMemo |
length of memo string + 1 |
|
ftDBaseOle |
number of bytes of blob data |
|
ftParadoxOle |
number of bytes of blob data |
|
ftOraBlob |
number of bytes of blob data |
|
ftOraClob |
number of bytes of blob data |
|
ftTypedBinary |
number of bytes of data |
|
ftADT |
0 |
|
ftArray |
0 |
|
ftDataSet |
0 |
|
ftReference |
0 |
|
ftCursor |
0 |
|
ftUnknown |
raises an EDatabaseError exception |
Note: The size returned by GetDataSize is the size required for the physical database representation of the Value. The field object that corresponds to that physical database field may store its data in another format requiring a different number of bytes.