Btrieve GetNextExtended 'UC‘选项只返回一次记录
Btrieve GetNextExtended 'UC‘选项只返回一次记录
提问于 2011-01-19 09:42:37
我正在开发普及的SQL2000i SP4并通过Btrieve访问我的数据。最近，我深入研究了GetNextExtended操作，并使用了“EG”选项，但是第一条记录始终被忽略。为了考虑到第一个记录，我决定切换到'UC‘选项，但这导致相同的记录被反复返回。我生成的数据库不包含“术语”。
任何帮助都将不胜感激。
'Form1 - just a form with one button on it
Option Explicit
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
(Destination As Any, Source As Any, ByVal Length As Long)
Private Sub Command_Click()
GetAllRecords
End Sub
Private Sub GetAllRecords()
Dim boolContinueLoop As Boolean
Dim objBtrvAPI As clsBtrvAPI
Set objBtrvAPI = New clsBtrvAPI
objBtrvAPI.OpenConnection "C:\Pastel09\_Demo\accrecpt.dat"
objBtrvAPI.GetFirst
boolContinueLoop = True
Do
objBtrvAPI.Record = GenerateGetNextExtendedDataBuffer()
objBtrvAPI.GetNextExtended
If (Not objBtrvAPI.EOF) Then
'Read record - not necessary for this test
End If
boolContinueLoop = (Not objBtrvAPI.EOF)
Loop Until Not boolContinueLoop
objBtrvAPI.CloseConnection
Set objBtrvAPI = Nothing
End Sub
Private Function GenerateGetNextExtendedDataBuffer() As Byte()
Dim intRecordImageLength As Integer
Dim bytDataBuffer() As Byte
Dim intDataBufferElementCount As Integer
Dim intNoOfLeadingBytesReturnedByExtendedOp As Integer
intRecordImageLength = 94
ReDim bytDataBuffer(0)
AddIntToByteArray bytDataBuffer, intDataBufferElementCount, 0 'Total data buffer size - placeholder, value will be assigned later
AddStringToByteArray bytDataBuffer, intDataBufferElementCount, "UC" 'Begin with the current record
AddIntToByteArray bytDataBuffer, intDataBufferElementCount, 0 'Max Reject Count
AddIntToByteArray bytDataBuffer, intDataBufferElementCount, 0 'Number Of Terms
AddIntToByteArray bytDataBuffer, intDataBufferElementCount, 1 'Number of records to retrieve
AddIntToByteArray bytDataBuffer, intDataBufferElementCount, 1 'Number of fields to extract
AddIntToByteArray bytDataBuffer, intDataBufferElementCount, intRecordImageLength 'Field length - select the entire record in one field
AddIntToByteArray bytDataBuffer, intDataBufferElementCount, 0 'Field offset/position
'Eight bytes are returned on the GetNextExtended call
'2 bytes - number of records returned - at present only one record is returned at one time
'2 bytes - length of the record image
'4 bytes - a pointer to the record
intNoOfLeadingBytesReturnedByExtendedOp = 8
SetLeadingBytesToIndicateSize bytDataBuffer, intDataBufferElementCount
If (intDataBufferElementCount < intRecordImageLength + intNoOfLeadingBytesReturnedByExtendedOp) Then
MakeSize bytDataBuffer, intDataBufferElementCount, intRecordImageLength + intNoOfLeadingBytesReturnedByExtendedOp
End If
GenerateGetNextExtendedDataBuffer = bytDataBuffer
End Function
Public Sub AddIntToByteArray(ByRef pbytDataBuffer() As Byte, _
ByRef pintElementCount As Integer, _
ByVal pintValue As Integer)
Dim i As Integer
Dim byteValue() As Byte
byteValue = ConvertIntToByteArray(pintValue)
pintElementCount = pintElementCount + 2
ReDim Preserve pbytDataBuffer(pintElementCount - 1)
For i = 1 To 0 Step -1
pbytDataBuffer(pintElementCount - 1 - i) = byteValue(1 - i)
Next i
End Sub
Public Sub AddStringToByteArray(ByRef pbytDataBuffer() As Byte, _
ByRef pintElementCount As Integer, _
ByVal pstrValue As String)
Dim i As Integer
Dim strValueToConvert As String
Dim byteValue() As Byte
pintElementCount = pintElementCount + Len(pstrValue)
ReDim Preserve pbytDataBuffer(pintElementCount - 1)
strValueToConvert = StrReverse(pstrValue)
For i = Len(pstrValue) To 1 Step -1
pbytDataBuffer(pintElementCount - i) = Asc(Mid$(strValueToConvert, i, 1))
Next i
End Sub
Private Sub MakeSize(ByRef pbytDataBuffer() As Byte, _
ByRef pintElementCount As Integer, _
ByVal pintSize As Integer)
pintElementCount = pintSize
ReDim Preserve pbytDataBuffer(pintElementCount - 1)
End Sub
Private Sub SetLeadingBytesToIndicateSize(ByRef pbytDataBuffer() As Byte, _
ByRef pintElementCount As Integer)
Dim i As Integer
Dim byteSize() As Byte
byteSize = ConvertIntToByteArray(pintElementCount)
For i = 0 To UBound(byteSize)
pbytDataBuffer(i) = byteSize(i)
Next i
End Sub
Private Function ConvertIntToByteArray(ByVal pintValue As Integer) As Byte()
Dim byteArray(0 To 1) As Byte
CopyMemory byteArray(0), ByVal VarPtr(pintValue), Len(pintValue)
ConvertIntToByteArray = byteArray
End Function
'clsBtrvAPI
Option Explicit
Private Const KEY_BUFFER_LEN = 255
'Btrieve operations
Private Const B_OPEN = 0
Private Const B_CLOSE = 1
Private Const B_GETFIRST = 12
Private Const B_STAT = 15
Private Const B_GETNEXTEXTENDED = 36
Private Declare Function BTRCALL Lib "wbtrv32.dll" (ByVal OpCode As Integer, PositionBlock As Any, DataBuffer As Any, _
DataLength As Long, KeyBuffer As Any, ByVal KeyLength As Integer, _
ByVal KeyNumber As Integer) As Integer
Private Type TypePositionBlock
PosBlk(128) As Byte
End Type
Private Type TypeOwner
Owner As String * 8
End Type
Private Type TypeKeySpec
KeyPos As Integer
KeyLen As Integer
KeyFlags As Integer
KeyTot As String * 4
KeyType As String * 1
Reserved As String * 5
End Type
Private Type TypeStatFileSpecs
RecLen As Integer
PageSize As Integer
IndexTot As Integer
RecTot As String * 4
FileFlags As Integer
Reserved As String * 2
UnusedPages As Integer
KeyBuf(0 To 119) As TypeKeySpec
End Type
Private m_strDataFilePath As String
Private m_byteFilePosBlk As TypePositionBlock
Private m_boolFileOpen As Boolean
Private m_boolEOF As Boolean
Private m_byteRecordBuffer() As Byte
Private m_intKeyNum As Integer
Private Sub Class_Initialize()
m_strDataFilePath = ""
m_boolFileOpen = False
m_boolEOF = True
m_intKeyNum = 0
End Sub
Private Function GetRecordLen() As Integer
Dim typeStat As TypeStatFileSpecs
Dim strKeyBuffer As String
Dim lngDataBufferLen As Long
Dim intKeyBufferLen As Integer
Dim intStatus As Integer
lngDataBufferLen = Len(typeStat)
strKeyBuffer = Space$(KEY_BUFFER_LEN)
intKeyBufferLen = KEY_BUFFER_LEN
intStatus = BTRCALL(B_STAT, m_byteFilePosBlk, typeStat, lngDataBufferLen, _
ByVal strKeyBuffer, KEY_BUFFER_LEN, 0)
If (intStatus = 0) Then
'Successfull
GetRecordLen = typeStat.RecLen
End If
End Function
Public Sub CloseConnection()
Dim intStatus As Integer
intStatus = BTRCALL(B_CLOSE, m_byteFilePosBlk, "", 0, 0, 0, 0)
If (intStatus = 0) Then
m_boolFileOpen = False
End If
End Sub
Public Sub GetFirst(Optional ByVal pintKey As Integer = 0)
Dim lngDataBufferLen As Long
Dim strKeyBuffer As String
Dim intKeyBufferLen As Integer
Dim intStatus As Integer
If (m_boolFileOpen) Then
lngDataBufferLen = UBound(m_byteRecordBuffer)
strKeyBuffer = Space$(KEY_BUFFER_LEN)
intKeyBufferLen = KEY_BUFFER_LEN
intStatus = BTRCALL(B_GETFIRST, m_byteFilePosBlk, m_byteRecordBuffer(1), lngDataBufferLen, _
ByVal strKeyBuffer, intKeyBufferLen, pintKey)
If (intStatus = 0) Then
m_intKeyNum = pintKey
m_boolEOF = False
End If
End If
End Sub
Public Sub GetNextExtended()
Dim lngDataBufferLen As Long
Dim strKeyBuffer As String
Dim intStatus As Integer
If (m_boolFileOpen) Then
lngDataBufferLen = UBound(m_byteRecordBuffer) + 1
strKeyBuffer = Space$(KEY_BUFFER_LEN)
intStatus = BTRCALL(B_GETNEXTEXTENDED, m_byteFilePosBlk, m_byteRecordBuffer(0), lngDataBufferLen, _
ByVal strKeyBuffer, Len(strKeyBuffer), m_intKeyNum)
If (intStatus = 9 Or intStatus = 64) Then
m_boolEOF = True
Else
If (intStatus = 0) Then
m_boolEOF = False
Else
Debug.Assert False
End If
End If
End If
End Sub
Public Sub OpenConnection(Optional ByVal pstrDataFilePath As String)
Dim typeDataBuffer As TypeOwner
Dim strKeyBuffer As String
Dim lngDataBufferLen As Long
Dim intStatus As Integer
typeDataBuffer.Owner = ""
m_strDataFilePath = pstrDataFilePath
lngDataBufferLen = Len(typeDataBuffer)
strKeyBuffer = Chr(34) & m_strDataFilePath & Chr(34)
intStatus = BTRCALL(B_OPEN, _
m_byteFilePosBlk, _
typeDataBuffer, _
lngDataBufferLen, _
ByVal strKeyBuffer, _
KEY_BUFFER_LEN, _
0)
If (intStatus = 0) Then
m_boolFileOpen = True
ReDim m_byteRecordBuffer(1 To GetRecordLen)
End If
End Sub
Public Property Get DataFilePath() As String
DataFilePath = m_strDataFilePath
End Property
Public Property Let DataFilePath(ByVal pstrValue As String)
m_strDataFilePath = pstrValue
End Property
Public Property Get EOF() As Boolean
EOF = m_boolEOF
End Property
Public Property Get Record() As Byte()
Record = m_byteRecordBuffer
End Property
Public Property Let Record(ByRef pbytValue() As Byte)
m_byteRecordBuffer = pbytValue
End Property下面是MKDE跟踪日志的摘录，其中使用了“UC”选项，结果是重复返回相同的记录：
MicroKernel Database Engine [Workstation Edition] for Windows NT/95/98
trace file
Created : 24 January 2011 16:04:28
<In> 0001 Opcode : 0026 Crs ID : 0xffffffff Db Length : 00005
Keynum : ff Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d19 Time : Mon Jan 24 16:04:28 2011
DBuf: 00 00 00 00 00 - .....
KBuf: ?? - .
<Out>0001 Status : 0000 Crs ID : 0xffffffff Db Length : 00005
Keynum : ff Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d19 Time : Mon Jan 24 16:04:28 2011
DBuf: 07 00 5a 00 39 - ..Z.9
KBuf: ?? - .
---------------------------------------------------------------------
<In> 0002 Opcode : 0000 Crs ID : 0xffffffff Db Length : 00008
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1a Time : Mon Jan 24 16:04:28 2011
DBuf: 4e 4f 54 53 48 4f 57 4e - 00 NOTSHOWN.
KBuf: 43 3a 5c 50 61 73 74 65 - 6c 30 39 5c 5f 44 65 6d C:\Pastel09\_Dem
6f 5c 61 63 63 72 65 63 - 70 74 2e 64 61 74 00 00 o\accrecpt.dat..
00 00 00 0c bd 06 d4 84 - 6b 3e 3a 47 ac 10 5e 78 ....½.Ô„k>:G¬.^x
File: "C:\Pastel09\_Demo\accrecpt.dat"
<Out>0002 Status : 0000 Crs ID : 0x00010000 Db Length : 00008
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1d Time : Mon Jan 24 16:04:28 2011
DBuf: 4e 4f 54 53 48 4f 57 4e - 00 NOTSHOWN.
KBuf: 43 3a 5c 50 61 73 74 65 - 6c 30 39 5c 5f 44 65 6d C:\Pastel09\_Dem
6f 5c 61 63 63 72 65 63 - 70 74 2e 64 61 74 00 00 o\accrecpt.dat..
00 00 00 0c 43 4f 4d 50 - 32 5c 50 69 65 74 69 65 ....COMP2\Pietie
---------------------------------------------------------------------
<In> 0003 Opcode : 0015 Crs ID : 0x00010000 Db Length : 00028
Keynum : fe Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1d Time : Mon Jan 24 16:04:28 2011
DBuf: 00 00 d3 01 fe ff ff ff - 1e 23 9e 77 30 00 b0 01 ..Ó.þÿÿÿ.#žw0.°.
e8 cc 01 66 00 00 00 00 - 88 fe e9 05 èÌ.f.....þé.
KBuf: 00 00 00 00 00 00 01 00 - 88 fe e9 05 1c 00 00 00 .........þé.....
60 fe e9 05 00 00 b0 01 - 22 00 c9 01 00 00 00 00 `þé...°.".É.....
a4 03 00 00 b8 fe e9 01 - 68 00 b0 01 ff ff ff ff ¤...¸þé.h.°.ÿÿÿÿ
00 00 1a 00 08 00 00 00 - 00 07 db 4a 4d 81 4d 51 ..........ÛJM.MQ
00 00 00 00 ff ff ff ff - 00 00 00 00 00 00 00 00 ....ÿÿÿÿ........
00 00 f4 0c 57 52 f4 0c - ff 00 00 00 00 00 00 00 ..ô.WRô.ÿ.......
8c 5e 9d 77 9c 17 bb 75 - 9c 03 00 00 00 00 00 00 Œ^.wœ.»uœ.......
c4 17 bb 75 72 59 c5 fb - 00 00 00 00 00 00 00 00 Ä.»urYÅû........
<Out>0003 Status : 0000 Crs ID : 0x00010000 Db Length : 00013
Keynum : fe Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1d Time : Mon Jan 24 16:04:28 2011
DBuf: 09 00 80 03 09 0d 10 08 - 0c 0c 0c 01 0a .............
KBuf: 00 00 00 00 00 00 01 00 - 88 fe e9 05 0d 00 00 00 .........þé.....
60 fe e9 05 00 00 b0 01 - 22 00 c9 01 00 00 00 00 `þé...°.".É.....
a4 03 00 00 b8 fe e9 01 - 68 00 b0 01 ff ff ff ff ¤...¸þé.h.°.ÿÿÿÿ
00 00 1a 00 08 00 00 00 - 00 07 db 4a 4d 81 4d 51 ..........ÛJM.MQ
00 00 00 00 ff ff ff ff - 00 00 00 00 00 00 00 00 ....ÿÿÿÿ........
00 00 f4 0c 57 52 f4 0c - ff 00 00 00 00 00 00 00 ..ô.WRô.ÿ.......
8c 5e 9d 77 9c 17 bb 75 - 9c 03 00 00 00 00 00 00 Œ^.wœ.»uœ.......
c4 17 bb 75 72 59 c5 fb - 00 00 00 00 00 00 00 00 Ä.»urYÅû........
---------------------------------------------------------------------
<In> 0004 Opcode : 0015 Crs ID : 0x00010000 Db Length : 01936
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1e Time : Mon Jan 24 16:04:28 2011
DBuf: 33 00 cb ff ff ff ff ff - ff ff ff ff ff ff ff 00 3.Ëÿÿÿÿÿÿÿÿÿÿÿÿ.
00 00 00 00 00 00 00 00 - 00 80 03 09 0d 10 08 0c ................
0c 0c 01 0a 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 20 20 20 20 20 - 00 00 00 00 00 00 00 00 ... ........
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
KBuf: -
<Out>0004 Status : 0000 Crs ID : 0x00010000 Db Length : 00352
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1e Time : Mon Jan 24 16:04:28 2011
DBuf: 80 03 00 04 09 00 04 00 - 00 00 00 03 03 00 00 00 ................
05 00 08 00 13 01 04 00 - 00 00 00 00 00 00 00 00 ................
0d 00 01 00 03 01 04 00 - 00 00 00 00 00 00 00 00 ................
0d 00 01 00 13 01 04 00 - 00 00 00 00 00 00 01 00 ................
01 00 04 00 13 01 04 00 - 00 00 01 00 00 00 01 00 ................
05 00 08 00 03 01 04 00 - 00 00 00 00 00 00 01 00 ................
05 00 08 00 13 01 04 00 - 00 00 00 00 00 00 02 00 ................
14 00 01 00 13 01 04 00 - 00 00 00 00 00 00 02 00 ................
15 00 07 00 03 01 04 00 - 00 00 00 00 00 00 02 00 ................
14 00 01 00 13 01 04 00 - 00 00 00 00 00 00 03 00 ................
15 00 07 00 03 01 04 00 - 00 00 00 00 00 00 03 00 ................
01 00 04 00 13 01 04 00 - 00 00 01 00 00 00 04 00 ................
05 00 08 00 03 01 04 00 - 00 00 00 00 00 00 04 00 ................
14 00 01 00 13 01 04 00 - 00 00 00 00 00 00 05 00 ................
15 00 07 00 13 01 04 00 - 00 00 00 00 00 00 05 00 ................
01 00 04 00 03 01 04 00 - 00 00 01 00 00 00 05 00 ................
KBuf: -
---------------------------------------------------------------------
<In> 0005 Opcode : 0012 Crs ID : 0x00010000 Db Length : 00896
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1f Time : Mon Jan 24 16:04:28 2011
DBuf: 80 03 00 04 09 00 04 00 - 00 00 00 03 03 00 00 00 ................
05 00 08 00 13 01 04 00 - 00 00 00 00 00 00 00 00 ................
0d 00 01 00 03 01 04 00 - 00 00 00 00 00 00 00 00 ................
0d 00 01 00 13 01 04 00 - 00 00 00 00 00 00 01 00 ................
01 00 04 00 13 01 04 00 - 00 00 01 00 00 00 01 00 ................
05 00 08 00 03 01 04 00 - 00 00 00 00 00 00 01 00 ................
05 00 08 00 13 01 04 00 - 00 00 00 00 00 00 02 00 ................
14 00 01 00 13 01 04 00 - 00 00 00 00 00 00 02 00 ................
15 00 07 00 03 01 04 00 - 00 00 00 00 00 00 02 00 ................
14 00 01 00 13 01 04 00 - 00 00 00 00 00 00 03 00 ................
15 00 07 00 03 01 04 00 - 00 00 00 00 00 00 03 00 ................
01 00 04 00 13 01 04 00 - 00 00 01 00 00 00 04 00 ................
05 00 08 00 03 01 04 00 - 00 00 00 00 00 00 04 00 ................
14 00 01 00 13 01 04 00 - 00 00 00 00 00 00 05 00 ................
15 00 07 00 13 01 04 00 - 00 00 00 00 00 00 05 00 ................
01 00 04 00 03 01 04 00 - 00 00 01 00 00 00 05 00 ................
KBuf: 00 00 00 00 00 00 00 00 - 00 .........
<Out>0005 Status : 0000 Crs ID : 0x00010000 Db Length : 00896
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 00009d1f Time : Mon Jan 24 16:04:28 2011
DBuf: 01 00 00 00 52 43 31 30 - 30 30 30 31 01 05 41 42 ....RC100001..AB
43 44 45 44 41 41 41 41 - 41 41 41 67 00 1b 05 d8 CDEDAAAAAAAg...Ø
07 00 46 69 72 73 74 20 - 45 6e 74 72 79 20 20 20 ..First Entry
20 20 20 20 20 20 20 20 - 20 20 20 20 20 20 20 20
20 20 20 20 20 20 20 20 - 20 20 00 00 00 00 00 00 ......
00 00 59 40 00 00 00 00 - 00 00 24 40 00 00 00 00 ..Y@......$@....
00 c0 72 40 00 00 00 00 - 00 00 00 00 00 00 00 00 .Àr@............
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 41 6c 62 6f ............Albo
74 74 20 4c 69 6d 69 74 - 65 64 20 20 20 20 20 20 tt Limited
20 20 20 20 20 20 20 20 - 20 20 20 20 20 20 20 20
20 20 20 20 31 34 2f 33 - 33 20 4f 66 66 69 63 65 14/33 Office
20 43 72 65 73 63 65 6e - 74 20 20 20 20 20 20 20 Crescent
KBuf: 52 43 31 30 30 30 30 31 - 01 RC100001.
---------------------------------------------------------------------
<In> 0006 Opcode : 0036 Crs ID : 0x00010000 Db Length : 00102
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 0000ad9b Time : Mon Jan 24 16:04:32 2011
DBuf: 10 00 55 43 00 00 00 00 - 01 00 01 00 5e 00 00 00 ..UC........^...
41 41 67 00 1b 05 d8 07 - 00 46 69 72 73 74 20 45 AAg...Ø..First E
6e 74 72 79 20 20 20 20 - 20 20 20 20 20 20 20 20 ntry
20 20 20 20 20 20 20 20 - 20 20 20 20 20 20 20 20
20 00 00 00 00 00 00 00 - 00 59 40 00 00 00 00 00 ........Y@.....
00 24 40 00 00 00 00 00 - c0 72 40 00 00 00 00 00 .$@.....Àr@.....
00 00 00 00 00 00 - ......
KBuf: 20 20 20 20 20 20 20 20 - 20
<Out>0006 Status : 0000 Crs ID : 0x00010000 Db Length : 00102
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 0000ad9c Time : Mon Jan 24 16:04:32 2011
DBuf: 01 00 5e 00 00 0b 00 00 - 01 00 00 00 52 43 31 30 ..^.........RC10
30 30 30 31 01 05 41 42 - 43 44 45 44 41 41 41 41 0001..ABCDEDAAAA
41 41 41 67 00 1b 05 d8 - 07 00 46 69 72 73 74 20 AAAg...Ø..First
45 6e 74 72 79 20 20 20 - 20 20 20 20 20 20 20 20 Entry
20 20 20 20 20 20 20 20 - 20 20 20 20 20 20 20 20
20 20 00 00 00 00 00 00 - 00 00 59 40 00 00 00 00 ........Y@....
00 00 24 40 00 00 - ..$@..
KBuf: 52 43 31 30 30 30 30 31 - 01 RC100001.
---------------------------------------------------------------------
<In> 0007 Opcode : 0036 Crs ID : 0x00010000 Db Length : 00102
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 0000b345 Time : Mon Jan 24 16:04:34 2011
DBuf: 10 00 55 43 00 00 00 00 - 01 00 01 00 5e 00 00 00 ..UC........^...
30 30 30 31 01 05 41 42 - 43 44 45 44 41 41 41 41 0001..ABCDEDAAAA
41 41 41 67 00 1b 05 d8 - 07 00 46 69 72 73 74 20 AAAg...Ø..First
45 6e 74 72 79 20 20 20 - 20 20 20 20 20 20 20 20 Entry
20 20 20 20 20 20 20 20 - 20 20 20 20 20 20 20 20
20 20 00 00 00 00 00 00 - 00 00 59 40 00 00 00 00 ........Y@....
00 00 24 40 00 00 - ..$@..
KBuf: 20 20 20 20 20 20 20 20 - 20
<Out>0007 Status : 0000 Crs ID : 0x00010000 Db Length : 00102
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 0000b345 Time : Mon Jan 24 16:04:34 2011
DBuf: 01 00 5e 00 00 0b 00 00 - 01 00 00 00 52 43 31 30 ..^.........RC10
30 30 30 31 01 05 41 42 - 43 44 45 44 41 41 41 41 0001..ABCDEDAAAA
41 41 41 67 00 1b 05 d8 - 07 00 46 69 72 73 74 20 AAAg...Ø..First
45 6e 74 72 79 20 20 20 - 20 20 20 20 20 20 20 20 Entry
20 20 20 20 20 20 20 20 - 20 20 20 20 20 20 20 20
20 20 00 00 00 00 00 00 - 00 00 59 40 00 00 00 00 ........Y@....
00 00 24 40 00 00 - ..$@..
KBuf: 52 43 31 30 30 30 30 31 - 01 RC100001.
---------------------------------------------------------------------
<In> 0012 Opcode : 0001 Crs ID : 0x00010000 Db Length : 00000
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 0000d735 Time : Mon Jan 24 16:04:43 2011
DBuf: ?? - .
KBuf: ?? - .
<Out>0012 Status : 0000 Crs ID : 0x00000000 Db Length : 00000
Keynum : 00 Clnt ID : 00 00 00 00 00 00 00 00 00 00 F4 0C 57 52 F4 0C
Clock : 0000d737 Time : Mon Jan 24 16:04:43 2011
DBuf: ?? - .
KBuf: ?? - .
---------------------------------------------------------------------只是跟踪日志上的一个注释，从事务0008到0011，所有数据都与0007完全相同，因此为了一些非常需要的简洁性，这些条目被忽略了。在0011之后，我手动停止了循环，因为它会一直无限期地返回相同的记录。
回答 1
Stack Overflow用户
回答已采纳
发布于 2011-01-24 17:25:14
好吧，现在我看到问题了。由于要返回的记录数设置为1，因此只能得到1条记录。因为您将它设置为"UC"，它将从当前记录开始并返回一条记录.同样的记录，不管你运行了多少次代码。
在GetNextExtended中没有神奇的“返回表中的所有记录”。您需要将“要返回的记录数量”设置为适合大约62K的记录数量。最大值实际上是64K减去一些开销。实际上，PSQL文档中有一个公式。此外，"UC“选项只应在第一次调用GNE时使用。在此之后，将其切换到"EG“，这样它就会继续记录下去。您将继续进行is调用，直到返回状态9(文件结束)为止。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/4733721
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