1RDF::Query::Compiler::SUQsLe(r3)Contributed Perl DocumenRtDaFt:i:oQnuery::Compiler::SQL(3)
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6 RDF::Query::Compiler::SQL - Compile a SPARQL query directly to SQL.
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9 This document describes RDF::Query::Compiler::SQL version 2.918.
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12 This module's API and functionality should be considered deprecated.
13 If you need functionality that this module provides, please get in
14 touch <http://www.perlrdf.org/>.
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17 "new ( $parse_tree )"
18 Returns a new compiler object.
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20 "compile ()"
21 Returns a SQL query string for the specified parse tree.
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23 "emit_select"
24 Returns a SQL query string representing the query.
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26 "limit_clause"
27 Returns a SQL LIMIT clause, or an empty string if the query does
28 not need limiting.
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30 "order_by_clause"
31 Returns a SQL ORDER BY clause, or an empty string if the query does
32 not use ordering.
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34 "variable_columns ( $var )"
35 Given a variable name, returns the set of column aliases that store
36 the values for the column (values for Literals, URIs, and Blank
37 Nodes).
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39 "add_variable_values_joins"
40 Modifies the query by adding LEFT JOINs to the tables in the
41 database that contain the node values (for literals, resources, and
42 blank nodes).
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44 "patterns2sql ( \@triples, \$level, %args )"
45 Builds the SQL query in instance data from the supplied @triples.
46 $level is used as a unique identifier for recursive calls.
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48 %args may contain callback closures for the following keys:
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50 'where_hook'
51 'from_hook'
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53 When present, these closures are used to add SQL FROM and WHERE
54 clauses to the query instead of adding them directly to the
55 object's instance data.
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57 "expr2sql ( $expression, \$level, %args )"
58 Returns a SQL expression for the supplied query $expression.
59 $level is used as a unique identifier for recursive calls.
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61 %args may contain callback closures for the following keys:
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63 'where_hook'
64 'from_hook'
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66 When present, these closures are used to add necessary SQL FROM and
67 WHERE clauses to the query.
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69 "_mysql_hash ( $data )"
70 Returns a hash value for the supplied $data string. This value is
71 computed using the same algorithm that Redland's mysql storage
72 backend uses.
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74 "_mysql_node_hash ( $node )"
75 Returns a hash value (computed by "_mysql_hash" for the supplied
76 $node. The hash value is based on the string value of the node and
77 the node type.
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79 "qualify_uri ( $uri )"
80 Returns a fully qualified URI from the supplied $uri. $uri may
81 already be a qualified URI, or a parse tree for a qualified URI or
82 QName. If $uri is a QName, the namespaces defined in the query
83 parse tree are used to fully qualify.
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85 "add_function ( $uri, $function )"
86 Associates the custom function $function (a CODE reference) with
87 the specified URI, allowing the function to be called by query
88 FILTERs.
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90 "get_function ( $uri )"
91 If $uri is associated with a query function, returns a CODE
92 reference to the function. Otherwise returns "undef".
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95 Gregory Williams <gwilliams@cpan.org>
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99perl v5.32.0 2020-07-28 RDF::Query::Compiler::SQL(3)