delphi 的数据集
TFieldType = (ftUnknown, ftString, ftSmallint, ftInteger, ftWord,
ftBoolean, ftFloat, ftCurrency, ftBCD, ftDate, ftTime, ftDateTime,
ftBytes, ftVarBytes, ftAutoInc, ftBlob, ftMemo, ftGraphic, ftFmtMemo,
ftParadoxOle, ftDBaseOle, ftTypedBinary, ftCursor, ftFixedChar, ftWideString,
ftLargeint, ftADT, ftArray, ftReference, ftDataSet, ftOraBlob, ftOraClob,
ftVariant, ftInterface, ftIDispatch, ftGuid, ftTimeStamp, ftFMTBcd);
哪位好心人能从前到后解答一下吗,能给出是多少字节的更感谢!
特别是FTBCD是什么?希望哪位能给出占内存多少字节ftUnknown:未知数据类型
ftString:字符串
ftSmallint:短整型,不知是多少字节
ftInteger:整型
ftWord:这个经常用,可是不知道
ftBoolean:逻辑
ftFloat:浮点
ftCurrency 请问这个是货币类型吗,与FTbcd有什么区别?
ftBCD:
ftDate:日期
ftTime:时间
ftDateTime:日期时间型
ftBytes:是字节吗?
ftVarBytes:
ftAutoInc:
ftBlob:
ftMemo:
ftGraphic:
ftFmtMemo:
ftParadoxOle:
ftDBaseOle:
ftTypedBinary:
ftCursor:
ftFixedChar:
ftWideString:
ftLargeint:
ftADT:
ftArray:
ftReference:
ftDataSet:这个是数据集类型了吧,是指针吗?
ftOraBlob:
ftOraClob,
ftVariant:
ftInterface:
ftIDispatch:
ftGuid:
ftTimeStamp:
ftFMTBcd:
TFieldType = (ftUnknown, ftString, ftSmallint, ftInteger, ftWord,
ftBoolean, ftFloat, ftCurrency, ftBCD, ftDate, ftTime, ftDateTime,
ftBytes, ftVarBytes, ftAutoInc, ftBlob, ftMemo, ftGraphic, ftFmtMemo,
ftParadoxOle, ftDBaseOle, ftTypedBinary, ftCursor, ftFixedChar, ftWideString,
ftLargeint, ftADT, ftArray, ftReference, ftDataSet, ftOraBlob, ftOraClob,
ftVariant, ftInterface, ftIDispatch, ftGuid, ftTimeStamp, ftFMTBcd);
哪位好心人能从前到后解答一下吗,能给出是多少字节的更感谢!
特别是FTBCD是什么?希望哪位能给出占内存多少字节ftUnknown:未知数据类型
ftString:字符串
ftSmallint:短整型,不知是多少字节
ftInteger:整型
ftWord:这个经常用,可是不知道
ftBoolean:逻辑
ftFloat:浮点
ftCurrency 请问这个是货币类型吗,与FTbcd有什么区别?
ftBCD:
ftDate:日期
ftTime:时间
ftDateTime:日期时间型
ftBytes:是字节吗?
ftVarBytes:
ftAutoInc:
ftBlob:
ftMemo:
ftGraphic:
ftFmtMemo:
ftParadoxOle:
ftDBaseOle:
ftTypedBinary:
ftCursor:
ftFixedChar:
ftWideString:
ftLargeint:
ftADT:
ftArray:
ftReference:
ftDataSet:这个是数据集类型了吧,是指针吗?
ftOraBlob:
ftOraClob,
ftVariant:
ftInterface:
ftIDispatch:
ftGuid:
ftTimeStamp:
ftFMTBcd:
字段类型列表:
--------------------------------------------------------------------------------
TStringField { ftString ; String }
TWideStringField { ftWideString ; WideString }
TNumericField { }
TIntegerField { ftInteger ; Integer }
TLongWordField { ftLongWord ; LongWord }
TSmallintField { ftSmallint ; Smallint }
TShortintField { ftShortint ; Shortint }
TByteField { ftByte ; Byte }
TLargeintField { ftLargeint ; Int64 }
TWordField { ftWord ; Word }
TAutoIncField { ftAutoInc ; Integer }
TUnsignedAutoIncField { ftAutoInc ; Cardinal }
TFloatField { ftFloat ; Double }
TSingleField { ftSingle ; Single }
TCurrencyField { ftCurrency ; Currency }
TExtendedField { ftExtended ; Extended }
TBooleanField { ftBoolean ; WordBool }
TDateTimeField { ftDateTime ; DateTime }
TSQLTimeStampField { ftTimeStamp ; TSQLTimeStamp }
TSQLTimeStampField { ftTimeStampOffset; TSQLTimeStampOffset }
TDateField { ftDate ; Integer }
TTimeField { ftTime ; Integer }
TBinaryField { }
TBytesField { ftBytes ; * }
TVarBytesField { ftVarBytes ; * }
TBCDField { ftBCD ; * }
TFMTBCDField { ftFMTBCD ; * }
TBlobField { ftBlob ; * }
TMemoField { ftMemo ; * }
TWideMemoField { ftWideMemo ; * }
TGraphicField { ftGraphic ; * }
TObjectField { }
TADTField { ftADT ; * }
TArrayField { ftArray ; * }
TDataSetField { ftDataSet ; TDataSet }
TReferenceField { ftReference ; * }
TVariantField { ftVariant ; OleVariant }
TInterfaceField { ftInterface ; IUnknown }
TIDispatchField { ftIDispatch ; IDispatch }
TGuidField { ftGuid ; TGUID }
TAggregateField { ftUnknown ; * }http://www.cnblogs.com/del/archive/2010/01/27/1657349.html
----------------------------------
ftUnknown Unknown or undetermined
ftString Character or string field
ftSmallint 16-bit integer field
ftInteger 32-bit integer field
ftWord 16-bit unsigned integer field
ftBoolean Boolean field
ftFloat Floating-point numeric field
ftCurrency Money field
ftBCD Binary-Coded Decimal field that can be converted to Currency type without a loss of precision.
ftDate Date field
ftTime Time field
ftDateTime Date and time field
ftBytes Fixed number of bytes (binary storage)ftVarBytes Variable number of bytes (binary storage)
ftAutoInc Auto-incrementing 32-bit integer counter field
ftBlob Binary Large OBject field
ftMemo Text memo field
ftGraphic Bitmap field
ftFmtMemo Formatted text memo field
ftParadoxOle Paradox OLE field
ftDBaseOle dBASE OLE field
ftTypedBinary Typed binary field
ftCursor Output cursor from an Oracle stored procedure (TParam only)
ftFixedChar Fixed character field
ftWideString Wide string field
ftLargeint Large integer fieldftADT Abstract Data Type field
ftArray Array field
ftReference REF field
ftDataSet DataSet field
ftOraBlob BLOB fields in Oracle 8 tables
ftOraClob CLOB fields in Oracle 8 tables
ftVariant Data of unknown or undetermined type
ftInterface References to interfaces (IUnknown)
ftIDispatch References to IDispatch interfaces
ftGuid globally unique identifier (GUID) values
ftTimeStamp Date and time field accessed through dbExpress
ftFMTBcd Binary-Coded Decimal field that is too large for ftBCD.
至于长度就是1个字节,因为没有那么多枚举元素。
我一般在使用的时候,需要数值比对,都是integer强制转换。