ActiveX Data Objects

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????? ActiveX Data Objects

• ???17 ?, ?????Borland Database Engine (??BDE)
  ????????, ???ActiveX Data Objects(????ADO)????????
  ???????????Borland ???Delphi ?CBuilder ??????,
  ?????ADO ?????????????ADO ???????, ?????,
  ??ADOTable ?ADOQuery ????BDE ?Table ?Query ??????
• ADO???????
• ????????
• ????
• ?????

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ADO ?BDE ???

• ???16 ?, ?????BCB ?????????4 ?, ???BDE ?ADO
  ?dbExpress ?InterBase, ??????????, ??BDE
  ?ADO?dbExpress ?InterBase ????????
• ?BDE ???, ???????Table ?Query ?QuickRep
  ??????????????????????????????????ADO??,
  ???????????????????, ????, ???????, ???ADO
  ?????????????, ???BDE ??????ADO ?????????,
  ?????????

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2 1 -1 ADO ???????

• ???17-1 ?, ?????BDE ??????????, ???ADO??, ????BDE
  ???Table ???ADO ???ADOTable ??????, ?????????

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??21-1a

• ??ADOTable ???????????, ??school.mdb ?stugrade
  ????

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2 1 - 2 ????????

• ?BDE ???, ????????Table ?Query ??, ?ADO ??,
  ??ADOTable ?ADOQuery ?????

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• ADOTable
• ADOTable ?Table ????????????????, ????????,
  ??????????, ??????????????????????????????????????
  ??????????
• ???
• ADOTable ???????????,??FieldByName
  ?Fields??????????????
• ADOTable1-FieldValues" ????"
• ADOTable1-FieldByName(" ????")-??????
• ADOTable1-Fields-Fields????-??????

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• ??????,????????AsVariant ?AsString ?AsInteger
  ?AsFloat ?AsCurrency ?AsDateTime ?AsBoolean
  ???????????Text1 ??,????AsString ,??????String
  ?????,???????????0 ?Name ????Edit1 ???
• Edit1-Text ADOTable1-FieldValues"Name"
• Edit1-Text ADOTable1-FieldByName("Name")-AsSt
  ring
• Edit1-Text ADOTable1-Fields-Fields0-AsStri
  ng
• ??????????????,?????????????????????,???????Name
  ???????
• ADOTable1Name-Value // ??????
• ADOTable1Name-AsString

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• ????
• ?????ADOTable ????????, ???????, ??????????????,
  ???????????, ?????????????, ???????????,
  ??????????????????, ??????

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(No Transcript)
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??21-2a

• ???????????????????

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??????

• ??????????????, ??????????, ??????????????????????
  ??ADOTable1name ?ADOTable1chi ?ADOTable1eng
  ?????????, ???????????????????,
  ??????ADOTable1name ??????Edit1???
• Edit1-TextADOTable1name-AsString

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??21-2b

• ?????????????

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?????

• ????????????, ??????Insert ?Post ??, ??Insert
  ?????????????Post ????????????????????????????,
  ????FieldByName (" ????") ?????,
  ??????????????????????????, ??????????????????????
  ??

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• // ?????????????AsStr ing ?AsInteger
• ADOTable1-Insert()
• // ??1 ????String
• ADOTable1-FieldByName(" ????1")-AsString
• Edit1-Text
• // ??2 ????Integer
• ADOTable1-FieldByName(" ????2")-AsInteger
• StrToInt(Edit2-Text)
• ADOTable1-Post()
• ??????, ??Test1.mdb ?grade ??????????
• // ?????????????AsStr ing ?AsInteger
• ADOTable1-Insert()
• ADOTable1-FieldByName("Name")-AsString "???"
  
• ADOTable1-FieldByName("Chi")-AsInteger 92
• ADOTable1-FieldByName("Eng")-AsInteger 88
• ADOTable1-Post()

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??21-2c

• ???????(????test1.mdb ?grade ???)?

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?????

• ????????Delete ??????
• ADOTab le 1.De le te
• ???????????????????????????, ???????

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??21-2d

• ???????(???????????)

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?????

• ????????Edit ?Post ???, ?????
• ADOTable1-Edit()
• ADOTable1-FieldByName(" ????1")-AsString
• Edit1-Text
• ADOTable1-FieldByName(" ????2")-AsInteger
• StrToInt(Edit2-Text)
• / / ??????
• ADOTable1-Post()
• ???????????????????(??, DBEdi t),?????????????????
  ,??????????????????????
• ADOTable1-Post()
• ?????????grade ?????????????
• ADOTable1-Edit()
• ADOTable1-FieldByName("Name")-AsString "???"
  
• ADOTable1-FieldByName("Chi")-AsInteger 22
• ADOTable1-FieldByName("Eng")-AsInteger 33
• ADOTable1-Post()

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??21-2e

• ???????(???????)?
• 1. ??????????????, ??????????" ???" ????,
  ?????DBEdit ???????????, ?????" ???" ????

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• 2. ??????" ?????????", ???????????, ?
• ?????, ??????
• / / - - - - - - - - - - - - - - - - - - - - - - -
  - - - - - - - - - - - - - - - - - - - - - - - - -
  - - - - -
• / / ??????
• void _ _fastcall TForm1btnEdit1Click(TObject
  Sender)
• ADOTable1-Edit()
• ADOTable1-FieldByName("Name")-AsString "???"
  
• ADOTable1-FieldByName("Chi")-AsInteger 92
• ADOTable1-FieldByName("Eng")-AsInteger 88
• ADOTable1-Post()
• / / - - - - - - - - - - - - - - - - - - - - - - -
  - - - - - - - - - - - - - - - - - - - - - - - - -
  - - - - -

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• 3. ???????" ??????" ???, ???????????,?????????DBTe
  xt ?????????
• / / ?????????????
• void _ _fastcall TForm1btnEdit2Click(TObject
  Sender)
• ADOTable1-Post()

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• 4. ???????" ??????????" ???, ??????????
• void _ _fastcall TForm1btnEdit3Click(TObject
  Sender)
• ADOTable1-First()
• while (! ADOTable1-Eof)
• ADOTable1-Edit()
• ADOTable1-FieldByName("Chi")-AsInteger
• ADOTable1-FieldByName("Chi")-AsInteger 1.1
  
• ADOTable1-Post()
• ADOTable1-Next()

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?????

• ADO ????????, ????Locate ?Filter, ??????
• Locate
• Locate ?????
• virtual bool _ _fastcall Locate(const AnsiString
  KeyFields,
• const SystemVariant KeyValues,
• TLocateOptions Options)
• ????????
• KeyFields ?????????
• KeyValues ????????
• Options ?????????TlocateOptions ?????, ????,
  ??loCaseInsensitive ???????????, loPartialKey
  ?????????, ????" ??", ??" ?????" ?" ????????",
  ????????
• enum TLocateOption loCaseInsensitive,
  loPartialKey
• ??????, Locate ????true, ??????????????????
  ???false, ??????????

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??21-2f

• ????????

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Filter

• ?????Locate ?????????, ???????, ??"chi60"
  ?"chi??????Filter?Filter ?????
• ADOTable1-Filter " ??????????????"
• ADOTable1-Filteredtrue

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??21-2g

• ??Filter ??????

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??

• ADOTable ????Sort ??????, Sort ??????, ??????ASC,
  ??????, ASC ?DESC ??????????
• ADOTable1-Sort " ????"

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??21-2h

• ??Sort ??????

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ADOQuery

• ?BDE ???, ???Query ????SQL ??, ??ADO
  ??????ADOQuery ???SQL ???, ??????17-4 ??19 ???,
  ????ADOQuery ?????Query ??, ??????????ADOQuery
  ??test1.mdb ?grade ????

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??21-2i

• ??ADOQuery ???(????DBGrid ??test1.mdb ?grade ????

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21 - 3 ????
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ADOConnection

• ???ADOTable ?ADOQuery ?????????????,
  ??????????????????, ???????ADOTable
  ?ADOQuery?????, ??????ConnectionString,
  ???????????????????????, ?????????????,
  ????ADOConnection ???
• ???????????ADOConnection ?????????, ??????????

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??21-3a

• ????????, ??????test1.mdb ?stuname, ??????stugrd ?

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21 - 4 ?????

• ADO ??????BDE ???????????, ?????????ADO
  ????????????????test1.mdb ?grade ?????ADO ????,
  ????????18 ??

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??21-4a

• ????????(?????test1.mdb ?grade ????)