好吧，我仔细研究了 DBF 和 FPT 文件结构的 MSDN 规范，结果是一个漂亮的 PHP 类，它可以同时打开一个 DBF 和（可选）一个 FPT 备忘录文件。这个类会给你一个又一个的记录，从而从备忘录文件中获取任何备忘录——如果打开的话。
class Prodigy_DBF {
private $Filename, $DB_Type, $DB_Update, $DB_Records, $DB_FirstData, $DB_RecordLength, $DB_Flags, $DB_CodePageMark, $DB_Fields, $FileHandle, $FileOpened;
private $Memo_Handle, $Memo_Opened, $Memo_BlockSize;
private function Initialize() {
if($this->FileOpened) {
fclose($this->FileHandle);
}
if($this->Memo_Opened) {
fclose($this->Memo_Handle);
}
$this->FileOpened = false;
$this->FileHandle = NULL;
$this->Filename = NULL;
$this->DB_Type = NULL;
$this->DB_Update = NULL;
$this->DB_Records = NULL;
$this->DB_FirstData = NULL;
$this->DB_RecordLength = NULL;
$this->DB_CodePageMark = NULL;
$this->DB_Flags = NULL;
$this->DB_Fields = array();
$this->Memo_Handle = NULL;
$this->Memo_Opened = false;
$this->Memo_BlockSize = NULL;
}
public function __construct($Filename, $MemoFilename = NULL) {
$this->Prodigy_DBF($Filename, $MemoFilename);
}
public function Prodigy_DBF($Filename, $MemoFilename = NULL) {
$this->Initialize();
$this->OpenDatabase($Filename, $MemoFilename);
}
public function OpenDatabase($Filename, $MemoFilename = NULL) {
$Return = false;
$this->Initialize();
$this->FileHandle = fopen($Filename, "r");
if($this->FileHandle) {
// DB Open, reading headers
$this->DB_Type = dechex(ord(fread($this->FileHandle, 1)));
$LUPD = fread($this->FileHandle, 3);
$this->DB_Update = ord($LUPD[0])."/".ord($LUPD[1])."/".ord($LUPD[2]);
$Rec = unpack("V", fread($this->FileHandle, 4));
$this->DB_Records = $Rec[1];
$Pos = fread($this->FileHandle, 2);
$this->DB_FirstData = (ord($Pos[0]) + ord($Pos[1]) * 256);
$Len = fread($this->FileHandle, 2);
$this->DB_RecordLength = (ord($Len[0]) + ord($Len[1]) * 256);
fseek($this->FileHandle, 28); // Ignoring "reserved" bytes, jumping to table flags
$this->DB_Flags = dechex(ord(fread($this->FileHandle, 1)));
$this->DB_CodePageMark = ord(fread($this->FileHandle, 1));
fseek($this->FileHandle, 2, SEEK_CUR); // Ignoring next 2 "reserved" bytes
// Now reading field captions and attributes
while(!feof($this->FileHandle)) {
// Checking for end of header
if(ord(fread($this->FileHandle, 1)) == 13) {
break; // End of header!
} else {
// Go back
fseek($this->FileHandle, -1, SEEK_CUR);
}
$Field["Name"] = trim(fread($this->FileHandle, 11));
$Field["Type"] = fread($this->FileHandle, 1);
fseek($this->FileHandle, 4, SEEK_CUR); // Skipping attribute "displacement"
$Field["Size"] = ord(fread($this->FileHandle, 1));
fseek($this->FileHandle, 15, SEEK_CUR); // Skipping any remaining attributes
$this->DB_Fields[] = $Field;
}
// Setting file pointer to the first record
fseek($this->FileHandle, $this->DB_FirstData);
$this->FileOpened = true;
// Open memo file, if exists
if(!empty($MemoFilename) and file_exists($MemoFilename) and preg_match("%^(.+).fpt$%i", $MemoFilename)) {
$this->Memo_Handle = fopen($MemoFilename, "r");
if($this->Memo_Handle) {
$this->Memo_Opened = true;
// Getting block size
fseek($this->Memo_Handle, 6);
$Data = unpack("n", fread($this->Memo_Handle, 2));
$this->Memo_BlockSize = $Data[1];
}
}
}
return $Return;
}
public function GetNextRecord($FieldCaptions = false) {
$Return = NULL;
$Record = array();
if(!$this->FileOpened) {
$Return = false;
} elseif(feof($this->FileHandle)) {
$Return = NULL;
} else {
// File open and not EOF
fseek($this->FileHandle, 1, SEEK_CUR); // Ignoring DELETE flag
foreach($this->DB_Fields as $Field) {
$RawData = fread($this->FileHandle, $Field["Size"]);
// Checking for memo reference
if($Field["Type"] == "M" and $Field["Size"] == 4 and !empty($RawData)) {
// Binary Memo reference
$Memo_BO = unpack("V", $RawData);
if($this->Memo_Opened and $Memo_BO != 0) {
fseek($this->Memo_Handle, $Memo_BO[1] * $this->Memo_BlockSize);
$Type = unpack("N", fread($this->Memo_Handle, 4));
if($Type[1] == "1") {
$Len = unpack("N", fread($this->Memo_Handle, 4));
$Value = trim(fread($this->Memo_Handle, $Len[1]));
} else {
// Pictures will not be shown
$Value = "{BINARY_PICTURE}";
}
} else {
$Value = "{NO_MEMO_FILE_OPEN}";
}
} else {
$Value = trim($RawData);
}
if($FieldCaptions) {
$Record[$Field["Name"]] = $Value;
} else {
$Record[] = $Value;
}
}
$Return = $Record;
}
return $Return;
}
function __destruct() {
// Cleanly close any open files before destruction
$this->Initialize();
}
}
该类可以这样使用：
$Test = new Prodigy_DBF("customer.DBF", "customer.FPT");
while(($Record = $Test->GetNextRecord(true)) and !empty($Record)) {
print_r($Record);
}
这可能不是一个完美的课程，但它对我有用。随意使用此代码，但请注意，该类非常宽容 - 它不关心 fread() 和 fseek() 是否返回 true 或其他任何内容 - 因此您可能希望在使用之前对其进行一些改进。
另请注意，目前没有使用许多私有变量，例如记录数、记录大小等。
我替换了这段代码：
fseek($this->Memo_Handle, (trim($RawData) * $this->Memo_BlockSize)+8);
$Value = trim(fread($this->Memo_Handle, $this->Memo_BlockSize));
使用此代码：
fseek($this->Memo_Handle, (trim($RawData) * $this->Memo_BlockSize)+4);
$Len = unpack("N", fread($this->Memo_Handle, 4));
$Value = trim(fread($this->Memo_Handle, $Len[1] ));
这对我有帮助
虽然不是 PHP，但 VFP 是从 1 开始的引用，我认为 PHP 是从零开始的引用，因此您必须相应地进行解密和调整，但这很有效，希望您能够在完成后发布您的这部分版本。
VFP 中的 FILETOSTR() 将打开一个文件，并将整个内容作为字符串读取到单个内存变量中——所有转义键、高字节字符等都完好无损。您可能需要依赖 FOPEN()、FSEEK()、FCLOSE() 等。
MemoTest.FPT 是我的示例备忘录表/文件 fpt1 = FILETOSTR( "MEMOTEST.FPT" )
首先，您必须检测创建文件时使用的 MEMO BLOCK SIZE。通常这将是 64 字节，但根据您在帖子中的链接。
标头位置 6-7 标识大小（VFP，位置 7 和 8）。第一个字节是高位
nBlockSize = ASC( SUBSTR( fpt1, 7, 1 )) * 256 + ASC( SUBSTR( fpt1, 8, 1 ))
现在，在您的个人记录中。无论您的 DBF 结构中哪里有备注 FIELD（并且每个记录结构可以有多个），都会有 4 个字节。在记录字段中，它标识了备忘录文件中存储内容的“块”。
MemoBytes = 您确定的字段位置的 4 个字节。这些将存储为 0-255 的 ASCII。该字段以第一个字节作为低位存储，第 4 个字节作为 256^3 = 16777216 存储。第一个使用的“块”将从头占用的备忘录 .fpt 文件规范的 512 位置偏移开始位置 0-511。
因此，如果您的第一个备注字段的内容为“8000”，其中 8 是实际的 0x08，而不是数字“8”，即 0x38，零是 0x00。
YourMemoField = "8000" （实际上使用 ascii，但为了便于阅读，显示十六进制预期值）
First Byte is ASCII value * 1 ( 256 ^ 0 )
Second Byte is ASCII value * 256 (256 ^ 1)
Third Byte is ASCII value * 65536 (256 ^ 2)
Fourth Byte is ASCII value * 16777216 (256 ^ 3)
nMemoBlock = byte1 + ( byte2 * 256 ) + ( byte3 * 65536 ) + ( byte4 * 16777216 )
现在，您需要 FSEEK() 到
FSEEK( handle, nMemoBlock * nBlockSize +1 )
对于您要查找的块的第一个字节。这将指向 BLOCK 标头。在这种情况下，根据规范，前 4 个字节标识块签名，后 4 个字节是内容的长度。对于这两个，字节首先以 HIGH-BYTE 存储。
从您的 FSEEK() 中，它与上面的 nMemoBlock 的高字节相反。这里的“Byte1-4”来自您的 FSEEK() 位置
nSignature = ( byte1 * 16777216 ) + ( byte2 * 65536 ) + ( byte3 * 256 ) + byte4
nMemoLength = ( byte5 * 16777216 ) + ( byte6 * 65536 ) + ( byte7 * 256 ) + byte8
现在，FSEEK() 到第 9 个字节（在您刚刚读取的标头的 8 个字节之后的数据的第一个实际字符，用于签名和备忘录长度）。这是您数据的开始。
现在，阅读其余内容...
FSEEK() +9 characters to new position
cFinalMemoData = FREAD( handle, nMemoLength )
我知道这并不完美，PHP 脚本也不完美，但它的伪代码足以说明事物的存储方式，并希望让您顺利上路。
同样，请在逐步完成调试过程时考虑到确保 0 或 1 个偏移量基础。为了帮助简化和测试这一点，我创建了一个带有 2 个字段的简单 .DBF……一个字符字段和一个备注字段，添加了一些记录和一些基本内容以确认所有内容、位置等。
<?
class Prodigy_DBF {
private $Filename, $DB_Type, $DB_Update, $DB_Records, $DB_FirstData, $DB_RecordLength, $DB_Flags, $DB_CodePageMark, $DB_Fields, $FileHandle, $FileOpened;
private $Memo_Handle, $Memo_Opened, $Memo_BlockSize;
private function Initialize() {
if($this->FileOpened) {
fclose($this->FileHandle);
}
if($this->Memo_Opened) {
fclose($this->Memo_Handle);
}
$this->FileOpened = false;
$this->FileHandle = NULL;
$this->Filename = NULL;
$this->DB_Type = NULL;
$this->DB_Update = NULL;
$this->DB_Records = NULL;
$this->DB_FirstData = NULL;
$this->DB_RecordLength = NULL;
$this->DB_CodePageMark = NULL;
$this->DB_Flags = NULL;
$this->DB_Fields = array();
$this->Memo_Handle = NULL;
$this->Memo_Opened = false;
$this->Memo_BlockSize = NULL;
}
public function __construct($Filename, $MemoFilename = NULL) {
$this->Prodigy_DBF($Filename, $MemoFilename);
}
public function Prodigy_DBF($Filename, $MemoFilename = NULL) {
$this->Initialize();
$this->OpenDatabase($Filename, $MemoFilename);
}
public function OpenDatabase($Filename, $MemoFilename = NULL) {
$Return = false;
$this->Initialize();
$this->FileHandle = fopen($Filename, "r");
if($this->FileHandle) {
// DB Open, reading headers
$this->DB_Type = dechex(ord(fread($this->FileHandle, 1)));
$LUPD = fread($this->FileHandle, 3);
$this->DB_Update = ord($LUPD[0])."/".ord($LUPD[1])."/".ord($LUPD[2]);
$Rec = unpack("V", fread($this->FileHandle, 4));
$this->DB_Records = $Rec[1];
$Pos = fread($this->FileHandle, 2);
$this->DB_FirstData = (ord($Pos[0]) + ord($Pos[1]) * 256);
$Len = fread($this->FileHandle, 2);
$this->DB_RecordLength = (ord($Len[0]) + ord($Len[1]) * 256);
fseek($this->FileHandle, 28); // Ignoring "reserved" bytes, jumping to table flags
$this->DB_Flags = dechex(ord(fread($this->FileHandle, 1)));
$this->DB_CodePageMark = ord(fread($this->FileHandle, 1));
fseek($this->FileHandle, 2, SEEK_CUR); // Ignoring next 2 "reserved" bytes
// Now reading field captions and attributes
while(!feof($this->FileHandle)) {
// Checking for end of header
if(ord(fread($this->FileHandle, 1)) == 13) {
break; // End of header!
} else {
// Go back
fseek($this->FileHandle, -1, SEEK_CUR);
}
$Field["Name"] = trim(fread($this->FileHandle, 11));
$Field["Type"] = fread($this->FileHandle, 1);
fseek($this->FileHandle, 4, SEEK_CUR); // Skipping attribute "displacement"
$Field["Size"] = ord(fread($this->FileHandle, 1));
fseek($this->FileHandle, 15, SEEK_CUR); // Skipping any remaining attributes
$this->DB_Fields[] = $Field;
}
// Setting file pointer to the first record
fseek($this->FileHandle, $this->DB_FirstData);
$this->FileOpened = true;
// Open memo file, if exists
if(!empty($MemoFilename) and file_exists($MemoFilename) and preg_match("%^(.+).fpt$%i", $MemoFilename)) {
$this->Memo_Handle = fopen($MemoFilename, "r");
if($this->Memo_Handle) {
$this->Memo_Opened = true;
// Getting block size
fseek($this->Memo_Handle, 6);
$Data = unpack("n", fread($this->Memo_Handle, 2));
$this->Memo_BlockSize = $Data[1];
}
}
}
return $Return;
}
public function GetNextRecord($FieldCaptions = false) {
$Return = NULL;
$Record = array();
if(!$this->FileOpened) {
$Return = false;
} elseif(feof($this->FileHandle)) {
$Return = NULL;
} else {
// File open and not EOF
fseek($this->FileHandle, 1, SEEK_CUR); // Ignoring DELETE flag
foreach($this->DB_Fields as $Field) {
$RawData = fread($this->FileHandle, $Field["Size"]);
// Checking for memo reference
if($Field["Type"] == "M" and $Field["Size"] == 4 and !empty($RawData)) {
// Binary Memo reference
$Memo_BO = unpack("V", $RawData);
if($this->Memo_Opened and $Memo_BO != 0) {
fseek($this->Memo_Handle, $Memo_BO[1] * $this->Memo_BlockSize);
$Type = unpack("N", fread($this->Memo_Handle, 4));
if($Type[1] == "1") {
$Len = unpack("N", fread($this->Memo_Handle, 4));
$Value = trim(fread($this->Memo_Handle, $Len[1]));
} else {
// Pictures will not be shown
$Value = "{BINARY_PICTURE}";
}
} else {
$Value = "{NO_MEMO_FILE_OPEN}";
}
} else {
if($Field["Type"] == "M"){
if(trim($RawData) > 0) {
fseek($this->Memo_Handle, (trim($RawData) * $this->Memo_BlockSize)+8);
$Value = trim(fread($this->Memo_Handle, $this->Memo_BlockSize));
}
}else{
$Value = trim($RawData);
}
}
if($FieldCaptions) {
$Record[$Field["Name"]] = $Value;
} else {
$Record[] = $Value;
}
}
$Return = $Record;
}
return $Return;
}
function __destruct() {
// Cleanly close any open files before destruction
$this->Initialize();
}
}
?>
我认为 PHP 中不太可能有 FoxPro 库。
您可能必须从头开始编写代码。对于字节读取，见fopen() fread() 和同事。
编辑：似乎有一个Visual FoxPro ODBC driver。您可能能够通过 PDO 和该连接器连接到 FoxPro 数据库。我不知道成功的机会有多大，需要做多少工作。
FPT 文件包含备忘录数据。在 DBF 中有 memo 类型的列，该列中的信息是指向 FPT 文件中条目的指针。
如果您从表中查询数据，您只需引用备注列即可获取数据。您不需要单独解析 FPT 文件中的数据。OLE DB 驱动程序（或 ODBC 驱动程序，如果您的文件是 VFP 6 或更早版本）应该只为您提供此信息。
有一个工具可以自动将您的 Visual FoxPro 数据迁移到 MySQL。您可能想检查一下是否可以节省一些时间：
并搜索“Stru2MySQL_2”以获取迁移数据结构的工具，并搜索“VFP2MySQL 数据上传程序”以获取帮助迁移的工具。
里克·舒默 VFP MVP
您可能还想检查 PHP dbase 库。它们与 DBF 文件配合得很好。