Description
Inserts data into a DataWindow control or DataStore from a file. The data can be tab-separated text, comma-separated text, XML, or dBase format 2 or 3.
Applies to
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DataWindow type |
Method applies to |
|---|---|
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PowerBuilder |
DataWindow control, DataWindowChild object, DataStore object |
Syntax
PowerBuilder
long dwcontrol.ImportFile ( {saveastype importtype}, string filename {, long startrow {, long endrow {, long startcolumn {, long endcolumn {, long dwstartcolumn } } } } } )
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Argument |
Description |
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|---|---|---|---|---|---|---|
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dwcontrol |
A reference to a DataWindow control or DataStore |
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importtype (optional for PowerBuilder) |
An enumerated value of the SaveAsType DataWindow constant or a number representing that value (see SaveAsType). If this argument is specified, the filename argument can be specified without an extension. Valid type arguments for ImportFile are:
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filename |
A string whose value is the name of the file from which you want to copy data. The file must be an ASCII, tab-separated file (TXT) or a comma-separated file (CSV), Extensible Markup Language file (XML), or dBase format 2 or 3 file (DBF). Specify the file's full name. If the optional importtype is not specified, the name must end in the appropriate extension. If filename is an empty string, or if it is null, ImportFile displays the File Open dialog box and allows the user to select a file. The remaining arguments are ignored. |
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startrow (optional for PowerBuilder) |
The number of the first detail row in the file that you want to copy. The default is 1. For default XML import, if startrow is supplied, the first N (startrow -1) elements are skipped, where N is the DataWindow row size. For template XML import, if startrow is supplied, the first (startrow -1) occurrences of the repetitive row mapping defined in the template are skipped. |
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endrow (optional for PowerBuilder) |
The number of the last detail row in the file that you want to copy. The default is the rest of the rows. For default XML import, if endrow is supplied, import stops when N * endrow elements have been imported, where N is the DataWindow row size. For template XML import, if endrow is supplied, import stops after endrow occurrences of the repetitive row mapping defined in the template have been imported. |
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startcolumn (optional for PowerBuilder) |
The number of the first column in the file that you want to copy. The default is 1. For default XML import, if startcolumn is supplied, import skips the first (startcolumn - 1) elements in each row. This argument has no effect on template XML import. |
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endcolumn (optional for PowerBuilder) |
The number of the last column in the file that you want to copy. The default is the rest of the columns. For default XML import, if endcolumn is supplied and is smaller than N, where N is the DataWindow row size, import skips the last (N - endcolumn) elements in each row. This argument has no effect on template XML import. |
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dwstartcolumn (optional for PowerBuilder) |
The number of the first column in the DataWindow control or DataStore that should receive data. The default is 1. This argument is supported for default and template XML import. |
Events
ImportFile may trigger an ItemError event.
Return value
Long. Returns the number of rows that were imported if it succeeds and one of the following negative integers if an error occurs:
-1 -- No rows or startrow value supplied is greater than the number of rows in the file
-2 -- Empty file
-3 -- Invalid argument
-4 -- Invalid input
-5 -- Could not open the file
-6 -- Could not close the file
-7 -- Error reading the text
-8 -- Unsupported file name suffix (must be *.txt, *.csv, *.dbf or *.xml)
-10 -- Unsupported dBase file format (not version 2 or 3)
-11 -- XML Parsing Error; XML parser libraries not found or XML not well formed
-12 -- XML Template does not exist or does not match the DataWindow
-13 -- Unsupported DataWindow style for import
-14 -- Error resolving DataWindow nesting
-15 -- File size exceeds limit
Usage
The format of the file can be indicated by specifying the optional importtype parameter, or by including the appropriate file extension.
The file should consist of rows of data. If the file includes column headings or row labels, set the startrow and startcolumn arguments to skip them. The datatypes and order of the DataWindow object's columns must match the columns of data in the file.
The startcolumn and endcolumn arguments control the number of columns imported from the file and the number of columns in the DataWindow that are affected. The dwstartcolumn argument specifies the first DataWindow column to be affected. The following formula calculates the last DataWindow to be affected.
dwstartcolumn + (endcolumn - startcolumn)
To let users select the file to import, specify a null string for filename. PowerBuilder displays the Select Import File dialog box. A drop-down list lets the user select the type of file to import.
Specifying a null string for filename
If you specify a null string for filename, the remaining arguments are ignored. All the rows and columns in the file are imported.
Double quotes
The location and number of double quote marks in a field in a tab-separated file affect how they are handled when the file is imported. If a string is enclosed in one pair of double quotes, the quotes are discarded. If it is enclosed in three pairs of double quotes, one pair is retained when the string is imported. If the string is enclosed in two pairs of double quotes, the first pair is considered to enclose a null string, and the rest of the string is discarded.
When there is a double quote at the beginning of a string, any characters after the second double quote are discarded. If there is no second double quote, the tab or comma character delimiting the fields is not recognized as a field separator and all characters up to the next occurrence of a double quote, including a carriage return, are considered to be part of the string. A validation error is generated if the combined strings exceed the length of the first string.
Double quotes after the first character in the string are rendered literally. Here are some examples of how tab-separated strings are imported into a two-column DataWindow:
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Text in file |
Result |
|---|---|
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"Joe" TAB "Donaldson" |
Joe Donaldson |
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Bernice TAB """Ramakrishnan""" |
Bernice "Ramakrishnan" |
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""Mary"" TAB ""Li"" |
Empty cells |
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"Mich"ael TAB """Mariam""" |
Mich "Mariam" |
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"Amy TAB Doherty" |
Amy<TAB>Doherty in first cell, second cell empty |
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3""" TAB 4" |
3""" 4" |
If an XML or CSV column contains a leading double quote, it is assumed to be part of the column value. A leading double quote has to be closed to mark the end of an item.
ImportFile does not support Crosstab DataWindow objects.
Examples
This statement inserts all the data in the file D:\TMP\EMPLOYEE.CSV into dw_employee starting at the first column:
dw_employee.ImportFile("D:\TMP\EMPLOYEE.CSV")This statement inserts all the data in the file D:\TMP\EMPLOYEE.XML into dw_employee starting at the first column:
dw_employee.ImportFile(XML!,"D:\TMP\EMPLOYEE")
The following statements are equivalent. Both import the contents of the XML file named myxmldata:
dw_control.ImportFile("myxmldata.xml")
dw_control.ImportFile(XML!, "myxmldata")This statement imports rows 1 to 200 of employee.xml, ignoring any template mappings before column 5:
dw_employee.ImportFile(XML!,"D:\TMP\EMPLOYEE.XML", 1, 200, 0, 0, 5)
This statement inserts the data from the file D:\TMP\EMPLOYEE.TXT into the DataWindow dw_employee. It copies rows 2 through 30 and columns 3 through 8 in the file to the DataWindow beginning in column 5. The result is 29 rows added to the DataWindow with data in columns 5 through 10:
dw_employee.ImportFile("D:\TMP\EMPLOYEE.TXT", &
2, 30, 3, 8, 5)See also
