| 1 |
# Copyright (c) 2001, 2002 by Intevation GmbH |
# Copyright (c) 2001, 2002, 2003 by Intevation GmbH |
| 2 |
# Authors: |
# Authors: |
| 3 |
# Bernhard Herzog <[email protected]> |
# Bernhard Herzog <[email protected]> |
| 4 |
# |
# |
| 32 |
Currently this is basically just a wrapper around dbflib. |
Currently this is basically just a wrapper around dbflib. |
| 33 |
""" |
""" |
| 34 |
|
|
| 35 |
|
# Implementation strategy regarding writing to a DBF file: |
| 36 |
|
# |
| 37 |
|
# Most of the time Thuban only needs to read from a table and it is |
| 38 |
|
# important that Thuban can work with read-only files. Therefore the |
| 39 |
|
# DBF file is opened only for reading initially. Only when |
| 40 |
|
# write_record is called we try to open the DBF file for writing as |
| 41 |
|
# well. If that succeeds the read/write DBF file will be used for |
| 42 |
|
# all IO afterwards. |
| 43 |
|
# |
| 44 |
|
# It's important to use the same DBF file object for both reading |
| 45 |
|
# and writing to make sure that reading a records after writing |
| 46 |
|
# returns the new values. With two separate objects this wouldn't |
| 47 |
|
# work because a DBF file object buffers some data |
| 48 |
|
|
| 49 |
def __init__(self, filename): |
def __init__(self, filename): |
| 50 |
self.filename = filename |
self.filename = filename |
| 51 |
self.dbf = dbflib.DBFFile(filename) |
self.dbf = dbflib.DBFFile(filename) |
| 52 |
|
|
| 53 |
|
# If true, self.dbf is open for writing. |
| 54 |
|
self._writable = 0 |
| 55 |
|
|
| 56 |
def Destroy(self): |
def Destroy(self): |
| 57 |
self.dbf.close() |
self.dbf.close() |
| 58 |
self.dbf = None |
self.dbf = None |
| 75 |
type = dbflib_fieldtypes[type] |
type = dbflib_fieldtypes[type] |
| 76 |
return type, name, width, prec |
return type, name, width, prec |
| 77 |
|
|
| 78 |
|
def field_info_by_name(self, fieldName): |
| 79 |
|
count = self.field_count() |
| 80 |
|
|
| 81 |
|
for i in range(count): |
| 82 |
|
info = self.field_info(i) |
| 83 |
|
if info[1] == fieldName: |
| 84 |
|
return info |
| 85 |
|
|
| 86 |
|
return None |
| 87 |
|
|
| 88 |
def read_record(self, record): |
def read_record(self, record): |
| 89 |
"""Return the record no. record as a dict mapping field names to values |
"""Return the record no. record as a dict mapping field names to values |
| 90 |
""" |
""" |
| 91 |
return self.dbf.read_record(record) |
return self.dbf.read_record(record) |
| 92 |
|
|
| 93 |
|
def write_record(self, record, values): |
| 94 |
|
"""Write the values into the record |
| 95 |
|
|
| 96 |
|
The values parameter may either be a dictionary or a sequence. |
| 97 |
|
|
| 98 |
|
If it's a dictionary the keys must be the names of the fields |
| 99 |
|
and their value must have a suitable type. Only the fields |
| 100 |
|
actually contained in the dictionary are written. Fields for |
| 101 |
|
which there's no item in the dict are not modified. |
| 102 |
|
|
| 103 |
|
If it's a sequence, all fields must be present in the right |
| 104 |
|
order. |
| 105 |
|
""" |
| 106 |
|
if not self._writable: |
| 107 |
|
new_dbf = dbflib.DBFFile(self.filename, "r+b") |
| 108 |
|
self.dbf.close() |
| 109 |
|
self.dbf = new_dbf |
| 110 |
|
self._writable = 1 |
| 111 |
|
self.dbf.write_record(record, values) |
| 112 |
|
self.dbf.commit() |
| 113 |
|
|
Parent Directory
| 
Revision Log
| 
Patch