NAME¶
RDF::Query::Compiler::SQL - Compile a SPARQL query directly to SQL.
VERSION¶
This document describes RDF::Query::Compiler::SQL version 2.912.
STATUS¶
This module's API and functionality should be considered deprecated. If you need
functionality that this module provides, please get in touch
<
http://www.perlrdf.org/>.
METHODS¶
- "new ( $parse_tree )"
- Returns a new compiler object.
- "compile ()"
- Returns a SQL query string for the specified parse tree.
- "emit_select"
- Returns a SQL query string representing the query.
- "limit_clause"
- Returns a SQL LIMIT clause, or an empty string if the query does not need
limiting.
- "order_by_clause"
- Returns a SQL ORDER BY clause, or an empty string if the query does not
use ordering.
- "variable_columns ( $var )"
- Given a variable name, returns the set of column aliases that store the
values for the column (values for Literals, URIs, and Blank Nodes).
- "add_variable_values_joins"
- Modifies the query by adding LEFT JOINs to the tables in the database that
contain the node values (for literals, resources, and blank nodes).
- "patterns2sql ( \@triples, \$level, %args )"
- Builds the SQL query in instance data from the supplied @triples. $level
is used as a unique identifier for recursive calls.
%args may contain callback closures for the following keys:
'where_hook'
'from_hook'
When present, these closures are used to add SQL FROM and WHERE clauses to
the query instead of adding them directly to the object's instance
data.
- "expr2sql ( $expression, \$level, %args )"
- Returns a SQL expression for the supplied query $expression. $level is
used as a unique identifier for recursive calls.
%args may contain callback closures for the following keys:
'where_hook'
'from_hook'
When present, these closures are used to add necessary SQL FROM and WHERE
clauses to the query.
- "_mysql_hash ( $data )"
- Returns a hash value for the supplied $data string. This value is computed
using the same algorithm that Redland's mysql storage backend uses.
- "_mysql_node_hash ( $node )"
- Returns a hash value (computed by "_mysql_hash" for the supplied
$node. The hash value is based on the string value of the node and the
node type.
- "qualify_uri ( $uri )"
- Returns a fully qualified URI from the supplied $uri. $uri may already be
a qualified URI, or a parse tree for a qualified URI or QName. If $uri is
a QName, the namespaces defined in the query parse tree are used to fully
qualify.
- "add_function ( $uri, $function )"
- Associates the custom function $function (a CODE reference) with the
specified URI, allowing the function to be called by query FILTERs.
- "get_function ( $uri )"
- If $uri is associated with a query function, returns a CODE reference to
the function. Otherwise returns "undef".
AUTHOR¶
Gregory Williams <gwilliams@cpan.org>