HOWTO: Append Records from Any Delimited File with Memo Data
ID: Q140294
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The information in this article applies to:
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Microsoft Visual FoxPro for Windows, versions 3.0, 6.0
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Microsoft FoxPro for Windows, versions 2.5, 2.5a, 2.5b, 2.6, 2.6a
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Microsoft FoxPro for MS-DOS, versions 2.5, 2.5a, 2.5b, 2.6, 2.6a
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Microsoft FoxPro for Macintosh, versions 2.5b, 2.5c, 2.6a
SUMMARY
This article shows by example how to append records from any delimited
ASCII text file into a predefined FoxPro table or .dbf file.
The intent of the program listed in this article is twofold. The first is
to address the inability of the APPEND command to read data into a memo
field. The second is to provide a wider range of support for source file
formats that the APPEND command does not support.
MORE INFORMATION
Here's an excerpt from the Visual FoxPro APPEND FROM Help Topic:
"A delimited file is an ASCII text file in which each record ends with a
carriage return and linefeed. Field contents are by default assumed to
be separated from each other by commas, and character
field values to be additionally delimited by double quotation marks."
The program listed in this article does not require linefeeds after the
carriage return, nor does it require that character data be delimited by
double quotation marks. Also, files do not have to be terminated with an
end-of-file marker (^Z), but the program will work fine if the end-of-file
marker is present. This flexibility is necessary because many applications
do not export their data in a format suitable for FoxPro's APPEND FROM
command.
Numeric, Float, Double, Integer, Currency, Date, and Memo fields from
delimited files can be imported if the data is in proper format. The date
format defaults to mm/dd/yy. Including the century portion of a date is
optional. FoxPro will import a date, such as 12/25/95, that doesn't include
the century assuming the date is in the twentieth century.
Date delimiters can be any non-numeric character except the delimiter that
separates the fields in the delimited file. Dates in other formats can be
imported if their format matches a date format available in SET DATE. To
import dates that are not in the default format, issue SET DATE with the
proper date format before using the program listed in this article
(Appendm.prg). To test if a date format can be successfully imported, use
it with CTOD(). If the date is acceptable to CTOD(), the date will import
properly.
Character strings with a length in excess of 10,000 characters have been
tested and work fine when imported into a memo field.
NOTE: Do not use a delimiting character that appears in the actual data.
Sample Code
Appendm.prg
Purpose:
* Append records from any delimited ASCII text file into a
* predefined FoxPro table or .dbf file. The intent of this program
* is twofold. The first is to address the inability of the
* APPEND command to read in data into a memo field. The second
* is to provide a wider range of support for source file formats.
Syntax:
DO AppendM [WITH <expC1>, <expC2&>[, <expC3>[, <expC4>]]]
Parameters:
<expC1>
* Specify the full name of the ASCII text file to append from
* with extension. If this parameter is used, then <expC2> and
* optionally <expC3> must be specified also. If this
* parameter is not specified, the user will be prompted for the
* file.
<expC2>
* Specify the field-delimiting character. This parameter must
* be used if <expC1> is specified. If <expC1> is not
* specified, this parameter is ignored.
Samples: ',' = COMMA
CHR(9) = TAB
<expC3>
* Specify the character field delimiting character. Use the
* null string ("") for none. This parameter is optional if
* <expC1> is specified. If <expC1> is not specified, this
* parameter is ignored.
<expC4>
* Specify the name of the table or .dbf file to append to. If the
* extension is not specified, .dbf is assumed. If a table or .dbf
* file is open in the current work area, this parameter will be
* ignored and the open table will be used.
Examples:
* For full prompting:
DO AppendM
* For a source file with comma-delimited fields and double-quotation-
* mark delimited character fields:
DO AppendM WITH 'SRCFILE.TXT', ',', '"'
* For a source file with tab-delimited fields and no character
* field delimiter:
DO AppendM WITH 'SRCFILE.TXT', CHR(9)
* For a source file with comma-delimited fields and double-quotation-
* mark delimited character fields with the current work area unused:
DO AppendM WITH 'SRCFILE.TXT', ',', '"', 'DESTFILE.DBF'
Notes:
* Before using this program, ensure that the target table or
* .dbf file is structured to accept the data from the source
* file, and ensure that the source file is in ASCII file format.
* Each record in the source file must be terminated with a
* carriage return (CR). Linefeeds (LF) following a CR are
* also supported. The program will address text files with
* any field delimiters. Character data fields may optionally be
* delimited. An end-of-file marker (^Z) is supported but not
* required.
PARAMETERS cTextFile, cFieldDelim, cChrFldDelim, cTableFile
IF TYPE( "cTextFile" ) = 'L'
cTextFile = ''
ENDIF
IF TYPE( "cFieldDelim" ) = 'L'
cFieldDelim = ''
ENDIF
IF TYPE( "cChrFldDelim" ) = 'L'
cChrFldDelim = ''
ENDIF
IF TYPE( "cTableFile" ) = 'L'
cTableFile = ''
ENDIF
* Attempt to get and/or open the table or .dbf file
* If successful, continue; otherwise, Return
IF USED()
cDBF_File = ALIAS()
ELSE
IF EMPTY( cTableFile )
cDBF_File = GETFILE( 'DBF', 'Append to:')
ELSE
IF !FILE( cTableFile ) AND !FILE( cTableFile + '.DBF' )
cDBF_File = GETFILE( 'DBF', 'Append to:')
ELSE
cDBF_File = cTableFile
ENDIF
ENDIF
IF !EMPTY( cDBF_File )
USE (cDBF_File)
ELSE
?? CHR(7)
WAIT WINDOW "No Table/DBF Selected to Append To!"
RETURN
ENDIF
ENDIF
* Attempt to get ASCII text file
* If successful, continue; otherwise, Return
IF EMPTY( cTextFile )
cTXT_File = GETFILE( 'TXT', 'Source:')
ELSE
IF !FILE( cTextFile )
cTXT_File = GETFILE( 'TXT', 'Source:')
ELSE
cTXT_File = cTextFile
ENDIF
ENDIF
IF EMPTY( cTXT_File )
?? CHR(7)
WAIT WINDOW "No Text File Selected to Append From!"
RETURN
ENDIF
* Verify Delimiting Characters. If successful,
* continue; otherwise, Return
IF EMPTY( cTextFile )
DEFINE WINDOW wGetDelims ;
FROM 1,1 TO 15,60 ;
TITLE "Delimiters" ;
NOCLOSE NOFLOAT NOGROW NOMDI NOMINIMIZE NOSHADOW NOZOOM
MOVE WINDOW wGetDelims CENTER
ACTIVATE WINDOW wGetDelims NOSHOW
CLEAR
@3,10 SAY "Press the Field Delimiting Character"
@5,10 SAY "ie.. COMMA = <,> or TAB = <TAB KEY>"
@7,29 say "" COLOR I
ACTIVATE WINDOW wGetDelims
nFieldDelim = INKEY(0,'S')
IF nFieldDelim = 9 or nFieldDelim > 32 and nFieldDelim < 127
cFieldDelim = CHR( nFieldDelim )
ENDIF
@3,5 SAY "Press the Character Field Delimiting Character"
@5,6 SAY "Typically DOUBLE-QUOTE, Press ENTER for None"
@7,29 say "" COLOR I
nChrFldDelim = INKEY(0,'S')
CLEAR
IF nChrFldDelim > 32 and nChrFldDelim < 127
cChrFldDelim =CHR( nChrFldDelim )
ELSE
cChrFldDelim = "" && No delimiter
ENDIF
DEACTIVATE WINDOW wGetDelims NOSHOW
RELEASE WINDOW wGetDelims
ENDIF
IF LEN( cFieldDelim ) = 0
?? CHR(7)
WAIT WINDOW "No Field Delimiting character Specified!"
RETURN
ENDIF
* Attempt to open text file with low-level handle.
* If the test is successful, continue; otherwise,
* report reason for failure.
nFileHandle = FOPEN( cTXT_File )
IF nFileHandle < 0
DO ErrHand WITH FERROR(), cTXT_File
RETURN .F.
ENDIF
* Create an array of database structure.
* Determine number of records in array for
* loop counting.
=AFIELDS( aStructure )
nRows = ALEN( aStructure, 1 )
* Begin DO WHILE loop and continue until end of
* file marker is reached in text file.
nFileSize = FSEEK( nFileHandle, 0, 2 )
= FSEEK( nFileHandle, 0, 0 )
nBytesRead = 0
RecsApnd = 0
lChrFldDelimFlag = LEN(cChrFldDelim ) # 0
WAIT WINDOW ' Records Appended: ' + LTRIM( STR( RecsApnd )) + ;
CHR(13) + ' Percent Completed: ' + ;
LTRIM( STR( nBytesRead/nFileSize 100)) NOWAIT
DO WHILE !FEOF( nFileHandle )
APPEND BLANK
FOR i = 1 TO nRows
cFieldData = ReadField( cFieldDelim, cChrFldDelim )
DO CASE
CASE aStructure[i,2] $ "NY"
REPLACE &aStructure[i,1] WITH VAL( cFieldData )
CASE aStructure[i,2] = "D"
REPLACE &aStructure[i,1] WITH CTOD( cFieldData )
OTHERWISE
REPLACE &aStructure[i,1] WITH cFieldData
ENDCASE
WAIT WINDOW ' Records Appended: ' + LTRIM( STR( RecsApnd )) + ;
CHR(13) + ' Percent Completed: ' +;
LTRIM( STR( nBytesRead/nFileSize 100 )) NOWAIT
ENDFOR
RecsApnd = RecsApnd + 1
ENDDO
=FCLOSE( nFileHandle )
WAIT WINDOW ' Records Appended: ' + LTRIM( STR( RecsApnd )) + ;
CHR(13) + ' Percent Completed: ' + ;
LTRIM( STR( nBytesRead/nFileSize 100)) NOWAIT
RETURN
FUNCTION ReadField
PARAMETER cFieldDelim, cChrFldDelim
cAccumText = ""
lFldDelimFlag = .F.
DO WHILE !lFldDelimFlag AND !FEOF( nFileHandle )
cSingle = FREAD( nFileHandle, 1 )
nBytesRead = nBytesRead + 1
IF cSingle = cFieldDelim OR cSingle = CHR(13) OR ;
IIF( lChrFldDelimFlag, cSingle = cChrFldDelim, .F. )
IF cSingle = CHR(13)
cSingle = FREAD( nFileHandle, 1 )
nBytesRead = nBytesRead + 1
IF cSingle = CHR(10)
cSingle = FREAD( nFileHandle, 1 )
nBytesRead = nBytesRead + 1
IF !(cSingle = CHR(26) OR ASC(cSingle) = 0)
=FSEEK( nFileHandle, -1, 1 )
nBytesRead = nBytesRead - 1
ENDIF
ELSE
IF !(cSingle = CHR(26) OR ASC(cSingle) = 0)
=FSEEK( nFileHandle, -1, 1 )
nBytesRead = nBytesRead - 1
ENDIF
ENDIF
lFldDelimFlag = .T.
ENDIF
IF cSingle = cFieldDelim
lFldDelimFlag = .T.
ENDIF
cSingle = ""
ELSE
cAccumText = cAccumText + cSingle
ENDIF
ENDDO
RETURN cAccumText
PROCEDURE ErrHand
PARAMETERS nError, cFileName
DO CASE
CASE nError = 2
cReason = "File not found: " + cFileName
CASE nError = 4
cReason = "Unable to open ' + cFileName + '. Too many files open"
CASE nError = 5
cReason = "File access denied: " + cFileName
CASE nError = 6
cReason = "Error: Invalid file handle given"
CASE nError = 8
cReason = "Error: Out of memory"
CASE nError = 25
cReason = "Seek error (can't seek before start of file)"
CASE nError = 29
cReason = "Error: Disk is full"
CASE nError = 31
cReason = "Error opening file: " + cFileName
ENDCASE
?? CHR(7)
WAIT WINDOW cReason
RETURN
EOF Appendm.prg
Additional query words:
Keywords : kbcode kbVFp kbVFp600 FoxDos FoxWin FxtoolGeneral
Version : MACINTOSH:2.5b,2.5c,2.6a; MS-DOS:2.5,2.5a,2.5b,2.6,2.6a; WINDOWS:2.5,2.5a,2.5b,2.6,2.6a,3.0,6.0
Platform : MACINTOSH MS-DOS WINDOWS
Issue type : kbhowto
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