Crate dbase[−][src]

dbase is rust library meant to read and write dBase / FoxPro files.

Theses files are nowadays generally only found in association with shapefiles.

Reading

The Reader is the struct that you’ll need to use in order to read the content of a dBase file.

Once you have access to the records, you will have to match against the real FieldValue

Examples

use dbase::FieldValue;
let records = dbase::read("tests/data/line.dbf")?;
for record in records {
    for (name, value) in record {
        println!("{} -> {:?}", name, value);
        match value {
            FieldValue::Character(Some(string)) => println!("Got string: {}", string),
            FieldValue::Numeric(value) => println!("Got numeric value of  {:?}", value),
            _ => {}
        }
    }
}

You can also create a Reader and iterate over the records.

let mut reader = dbase::Reader::from_path("tests/data/line.dbf")?;
for record_result in reader.iter_records() {
    let record = record_result?;
    for (name, value) in record {
        println!("name: {}, value: {:?}", name, value);
    }
}

Deserialisation

If you know what kind of data to expect from a particular file you can use implement the ReadbableRecord trait to “deserialize” the record into your custom struct:

use std::io::{Read, Seek};
struct StationRecord {
    name: String,
    marker_col: String,
    marker_sym: String,
    line: String,
}

impl dbase::ReadableRecord for StationRecord {
    fn read_using<T>(field_iterator: &mut dbase::FieldIterator<T>) -> Result<Self, dbase::FieldIOError>
         where T: Read + Seek{
        Ok(Self {
            name: field_iterator.read_next_field_as()?.value,
            marker_col: field_iterator.read_next_field_as()?.value,
            marker_sym: field_iterator.read_next_field_as()?.value,
            line: field_iterator.read_next_field_as()?.value,
        })
    }
}
let mut reader = dbase::Reader::from_path("tests/data/stations.dbf")?;
let stations = reader.read_as::<StationRecord>()?;

assert_eq!(stations[0].name, "Van Dorn Street");
assert_eq!(stations[0].marker_col, "#0000ff");
assert_eq!(stations[0].marker_sym, "rail-metro");
assert_eq!(stations[0].line, "blue");

If you use the serde optional feature and serde_derive crate you can have the ReadbableRecord impletemented for you

extern crate serde_derive;


use std::io::{Read, Seek};
use serde_derive::Deserialize;

#[derive(Deserialize)]
struct StationRecord {
    name: String,
    marker_col: String,
    marker_sym: String,
    line: String,
}

let mut reader = dbase::Reader::from_path("tests/data/stations.dbf")?;
let stations = reader.read_as::<StationRecord>()?;

assert_eq!(stations[0].name, "Van Dorn Street");
assert_eq!(stations[0].marker_col, "#0000ff");
assert_eq!(stations[0].marker_sym, "rail-metro");
assert_eq!(stations[0].line, "blue");

Writing

In order to get a TableWriter you will need to build it using its TableWriterBuilder to specify the fields that constitute a record.

As for reading, you can serialize structs into a dBase file, given that they match the declared fields in when building the TableWriterBuilder by implementing the WritableRecord.

Examples

let mut reader = dbase::Reader::from_path("tests/data/stations.dbf")?;
let mut stations = reader.read()?;

let mut writer = dbase::TableWriterBuilder::from_reader(reader)
    .build_with_file_dest("stations.dbf").unwrap();

stations[0].get_mut("line").and_then(|_old| Some("Red".to_string()));
writer.write_records(&stations)?;

use dbase::{TableWriterBuilder, FieldName, WritableRecord, FieldWriter, FieldIOError};
use std::convert::TryFrom;
use std::io::{Cursor, Write};

struct User {
    nick_name: String,
    age: f64
}

impl WritableRecord for User {
    fn write_using<'a, W: Write>(&self, field_writer: &mut FieldWriter<'a, W>) -> Result<(), FieldIOError> {
        field_writer.write_next_field_value(&self.nick_name)?;
        field_writer.write_next_field_value(&self.age)?;
        Ok(())
    }
}

let mut writer = TableWriterBuilder::new()
    .add_character_field(FieldName::try_from("Nick Name").unwrap(), 50)
    .add_numeric_field(FieldName::try_from("Age").unwrap(), 20, 10)
    .build_with_dest(Cursor::new(Vec::<u8>::new()));


let records = User{
    nick_name: "Yoshi".to_string(),
    age: 32.0,
};

writer.write_record(&records);

If you use the serde optional feature and serde_derive crate you can have the WritableRecord impletemented for you.

extern crate serde_derive;

use serde_derive::Serialize;

use dbase::{TableWriterBuilder, FieldName, WritableRecord, FieldWriter};
use std::convert::TryFrom;
use std::io::{Cursor, Write};

#[derive(Serialize)]
struct User {
    nick_name: String,
    age: f64
}

let writer = TableWriterBuilder::new()
    .add_character_field(FieldName::try_from("Nick Name").unwrap(), 50)
    .add_numeric_field(FieldName::try_from("Age").unwrap(), 20, 10)
    .build_with_dest(Cursor::new(Vec::<u8>::new()));


let records = vec![User{
    nick_name: "Yoshi".to_string(),
    age: 32.0,
}];

    writer.write_records(&records);

Macros

dbase_record

macro to define a struct that implements the ReadableRecord and WritableRecord

Structs

Date	dBase representation of date
DateTime	FoxBase representation of a DateTime
Error	The error type for this crate
FieldIOError
FieldInfo	Struct giving the info for a record field
FieldIterator	Iterator over the fields in a dBase record
FieldName	Wrapping struct to create a FieldName from a String.
FieldWriter	Struct that knows how to write a record
NamedValue	Simple struct to wrap together the value with the name of the field it belongs to
Reader	Struct with the handle to the source .dbf file Responsible for reading the content
Record	Type definition of a generic record. A .dbf file is composed of many records
RecordIterator	Iterator over records contained in the dBase
TableInfo	Structs containing the information allowing to create a new TableWriter which would write file with the same record structure as another dbase file.
TableWriter	Structs that writes dBase records to a destination
TableWriterBuilder	Builder to be used to create a TableWriter.
Time	FoxBase representation of a time

Enums

ErrorKind
FieldConversionError	Errors that can happen when trying to convert a FieldValue into a more concrete type
FieldValue	Enum where each variant stores the record value

Traits

ReadableRecord	Trait to be implemented by structs that represent records read from a dBase file.
WritableRecord	Trait to be implemented by struct that you want to be able to write to (serialize) a dBase file

Functions

read	One liner to read the content of a .dbf file

Crate dbase⎘[−][src]

Crate dbase[−][src]