DBD::SQLite::VirtualTable::FileContent
Section: User Contributed Perl Documentation (3pm)
Updated: 2022-11-26
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NAME
DBD::SQLite::VirtualTable::FileContent -- virtual table for viewing file contents
SYNOPSIS
Within Perl :
$dbh->sqlite_create_module(fcontent => "DBD::SQLite::VirtualTable::FileContent");
Then, within SQL :
CREATE VIRTUAL TABLE tbl USING fcontent(
source = src_table,
content_col = content,
path_col = path,
expose = "path, col1, col2, col3", -- or "*"
root = "/foo/bar"
get_content = Foo::Bar::read_from_file
);
SELECT col1, path, content FROM tbl WHERE ...;
DESCRIPTION
A ``FileContent'' virtual table is bound to some underlying source
table, which has a column containing paths to files. The virtual
table behaves like a database view on the source table, with an added
column which exposes the content from those files.
This is especially useful as an ``external content'' to some
fulltext table (see DBD::SQLite::Fulltext_search) : the index
table stores some metadata about files, and then the fulltext engine
can index both the metadata and the file contents.
PARAMETERS
Parameters for creating a "FileContent" virtual table are
specified within the "CREATE VIRTUAL TABLE" statement, just
like regular column declarations, but with an '=' sign.
Authorized parameters are :
- "source"
-
The name of the source table.
This parameter is mandatory. All other parameters are optional.
- "content_col"
-
The name of the virtual column exposing file contents.
The default is "content".
- "path_col"
-
The name of the column in "source" that contains paths to files.
The default is "path".
- "expose"
-
A comma-separated list (within double quotes) of source column names
to be exposed by the virtual table. The default is "*", which means
all source columns.
- "root"
-
An optional root directory that will be prepended to the path column
when opening files.
- "get_content"
-
Fully qualified name of a Perl function for reading file contents.
The default implementation just slurps the entire file into a string;
but this hook can point to more sophisticated implementations, like for
example a function that would remove html tags. The hooked function is
called like this :
$file_content = $get_content->($path, $root);
AUTHOR
Laurent Dami <dami@cpan.org>
COPYRIGHT AND LICENSE
Copyright Laurent Dami, 2014.
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- PARAMETERS
-
- AUTHOR
-
- COPYRIGHT AND LICENSE
-
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Time: 07:58:45 GMT, April 19, 2024