Metadata¶

The following attributes are handled by DBI itself and not by DBD::File, thus they all work like expected:

    Active
    ActiveKids
    CachedKids
    CompatMode             (Not used)
    InactiveDestroy
    Kids
    PrintError
    RaiseError
    Warn                   (Not used)

The following DBI attributes are handled by DBD::File:

AutoCommit

Always on

ChopBlanks

Works

NUM_OF_FIELDS

Valid after "$sth-"execute>

NUM_OF_PARAMS

Valid after "$sth-"prepare>

NAME

Valid after "$sth-"execute>; undef for Non-Select statements.

NULLABLE

Not really working, always returns an array ref of one's, as DBD::CSV doesn't verify input data. Valid after "$sth-"execute>; undef for Non-Select statements.

These attributes and methods are not supported:

    bind_param_inout
    CursorName
    LongReadLen
    LongTruncOk

Additional to the DBI attributes, you can use the following dbh attribute:

f_dir

This attribute is used for setting the directory where CSV files are opened. Usually you set it in the dbh, it defaults to the current directory ("."). However, it is overwritable in the statement handles.

f_ext

This attribute is used for setting the file extension where (CSV) files are opened. There are several possibilities.

    DBI:CSV:f_dir=data;f_ext=.csv
    

In this case, DBD::File will open only "table.csv" if both "table.csv" and "table" exist in the datadir. The table will still be named "table". If your datadir has files with extensions, and you do not pass this attribute, your table is named "table.csv", which is probably not what you wanted. The extension is always case-insensitive. The table names are not.

    DBI:CSV:f_dir=data;f_ext=.csv/r
    

In this case the extension is required, and all filenames that do not match are ignored.

f_schema

This will set the schema name. Default is the owner of the folder in which the table file resides. "undef" is allowed.

    my $dbh = DBI->connect ("dbi:CSV:", "", "", {
        f_schema => undef,
        f_dir    => "data",
        f_ext    => ".csv/r",
        }) or die $DBI::errstr;
    

The effect is that when you get table names from DBI, you can force all tables into the same (or no) schema:

    my @tables $dbh->tables ();
    # no f_schema
    "merijn".foo
    "merijn".bar
    # f_schema => "dbi"
    "dbi".foo
    "dbi".bar
    # f_schema => undef
    foo
    bar
    

Driver private methods¶

data_sources

The "data_sources" method returns a list of subdirectories of the current directory in the form "DBI:CSV:f_dir=$dirname".

If you want to read the subdirectories of another directory, use

    my ($drh) = DBI->install_driver ("CSV");
    my (@list) = $drh->data_sources (f_dir => "/usr/local/csv_data" );
    

list_tables

This method returns a list of file names inside $dbh->{f_dir}. Example:

    my ($dbh) = DBI->connect ("DBI:CSV:f_dir=/usr/local/csv_data");
    my (@list) = $dbh->func ("list_tables");
    

Note that the list includes all files contained in the directory, even those that have non-valid table names, from the view of SQL.