Loading Fixed Cols File Formats

This command instructs pgloader to load data from a text file containing columns arranged in a fixed size manner. Here’s an example:

LOAD FIXED
     FROM inline
          (
           a from  0 for 10,
           b from 10 for  8,
           c from 18 for  8,
           d from 26 for 17 [null if blanks, trim right whitespace]
          )
     INTO postgresql:///pgloader
   TARGET TABLE fixed
          (
             a, b,
             c time using (time-with-no-separator c),
             d
          )

     WITH truncate

      SET work_mem to '14MB',
          standard_conforming_strings to 'on'

BEFORE LOAD DO
     $$ drop table if exists fixed; $$,
     $$ create table fixed (
         a integer,
         b date,
         c time,
         d text
        );
     $$;

 01234567892008052011431250firstline
    01234562008052115182300left blank-padded
 12345678902008052208231560another line
  2345609872014092914371500
  2345678902014092914371520

The fixed format command accepts the following clauses and options.

Fixed File Format Source Specification: FROM

Filename where to load the data from. Accepts an ENCODING option. Use the –list-encodings option to know which encoding names are supported.

The filename may be enclosed by single quotes, and could be one of the following special values:

  • inline

    The data is found after the end of the parsed commands. Any number of empty lines between the end of the commands and the beginning of the data is accepted.

  • stdin

    Reads the data from the standard input stream.

  • FILENAMES MATCHING

    The whole matching clause must follow the following rule:

    [ ALL FILENAMES | [ FIRST ] FILENAME ]
    MATCHING regexp
    [ IN DIRECTORY '...' ]
    

    The matching clause applies given regular expression (see above for exact syntax, several options can be used here) to filenames. It’s then possible to load data from only the first match of all of them.

    The optional IN DIRECTORY clause allows specifying which directory to walk for finding the data files, and can be either relative to where the command file is read from, or absolute. The given directory must exists.

Fields Specifications

The FROM option also supports an optional comma separated list of field names describing what is expected in the FIXED data file.

Each field name is composed of the field name followed with specific reader options for that field. Supported per-field reader options are the following, where only start and length are required.

  • start

    Position in the line where to start reading that field’s value. Can be entered with decimal digits or 0x then hexadecimal digits.

  • length

    How many bytes to read from the start position to read that field’s value. Same format as start.

Those optional parameters must be enclosed in square brackets and comma-separated:

  • terminated by

    See the description of field terminated by below.

    The processing of this option is not currently implemented.

  • date format

    When the field is expected of the date type, then this option allows to specify the date format used in the file.

    Date format string are template strings modeled against the PostgreSQL to_char template strings support, limited to the following patterns:

    • YYYY, YYY, YY for the year part
    • MM for the numeric month part
    • DD for the numeric day part
    • HH, HH12, HH24 for the hour part
    • am, AM, a.m., A.M.
    • pm, PM, p.m., P.M.
    • MI for the minutes part
    • SS for the seconds part
    • MS for the milliseconds part (4 digits)
    • US for the microseconds part (6 digits)
    • unparsed punctuation signs: - . * # @ T / and space

    Here’s an example of a date format specification:

    column-name [date format 'YYYY-MM-DD HH24-MI-SS.US']
    
  • null if

    This option takes an argument which is either the keyword blanks or a double-quoted string.

    When blanks is used and the field value that is read contains only space characters, then it’s automatically converted to an SQL NULL value.

    When a double-quoted string is used and that string is read as the field value, then the field value is automatically converted to an SQL NULL value.

  • trim both whitespace, trim left whitespace, trim right whitespace

    This option allows to trim whitespaces in the read data, either from both sides of the data, or only the whitespace characters found on the left of the streaing, or only those on the right of the string.

Fixed File Format Loading Options: WITH

When loading from a FIXED file, the following options are supported:

  • truncate

    When this option is listed, pgloader issues a TRUNCATE command against the PostgreSQL target table before reading the data file.

  • disable triggers

    When this option is listed, pgloader issues an ALTER TABLE … DISABLE TRIGGER ALL command against the PostgreSQL target table before copying the data, then the command ALTER TABLE … ENABLE TRIGGER ALL once the COPY is done.

    This option allows loading data into a pre-existing table ignoring the foreign key constraints and user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use with care.

  • skip header

    Takes a numeric value as argument. Instruct pgloader to skip that many lines at the beginning of the input file.