mentat/mentat_transaction/query/index.html

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<p class='location'>Module query</p><div class="sidebar-elems"><div class="block items"><ul><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#traits">Traits</a></li><li><a href="#functions">Functions</a></li><li><a href="#types">Type Definitions</a></li></ul></div><p class='location'><a href='../index.html'>mentat_transaction</a></p><script>window.sidebarCurrent = {name: 'query', ty: 'mod', relpath: '../'};</script><script defer src="../sidebar-items.js"></script></div>
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<h1 class='fqn'><span class='in-band'>Module <a href='../index.html'>mentat_transaction</a>::<wbr><a class="mod" href=''>query</a></span><span class='out-of-band'><span id='render-detail'>
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[<span class='inner'>&#x2212;</span>]
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</span><a class='srclink' href='../../src/mentat_transaction/query.rs.html#11-466' title='goto source code'>[src]</a></span></h1>
<h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
<table>
<tr class=' module-item'>
<td><a class="struct" href="struct.Keyword.html"
title='struct mentat_transaction::query::Keyword'>Keyword</a></td>
<td class='docblock-short'>
<p>A keyword is a symbol, optionally with a namespace, that prints with a leading colon.
This concept is imported from Clojure, as it features in EDN and the query
syntax that we use.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="struct" href="struct.Known.html"
title='struct mentat_transaction::query::Known'>Known</a></td>
<td class='docblock-short'>
<p>A convenience wrapper around things known in memory: the schema and caches.
We use a trait object here to avoid making dozens of functions generic over the type
of the cache. If performance becomes a concern, we should hard-code specific kinds of
cache right here, and/or eliminate the Option.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="struct" href="struct.PlainSymbol.html"
title='struct mentat_transaction::query::PlainSymbol'>PlainSymbol</a></td>
<td class='docblock-short'>
<p>A simplification of Clojure's Symbol.</p>
</td>
</tr>
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<td><a class="struct" href="struct.QueryInputs.html"
title='struct mentat_transaction::query::QueryInputs'>QueryInputs</a></td>
<td class='docblock-short'>
<p>Define the inputs to a query. This is in two parts: a set of values known now, and a set of
types known now.
The separate map of types is to allow queries to be algebrized without full knowledge of
the bindings that will be used at execution time.
When built correctly, <code>types</code> is guaranteed to contain the types of <code>values</code> -- use
<code>QueryInputs::new</code> or <code>QueryInputs::with_values</code> to construct an instance.</p>
</td>
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<td><a class="struct" href="struct.QueryOutput.html"
title='struct mentat_transaction::query::QueryOutput'>QueryOutput</a></td>
<td class='docblock-short'>
</td>
</tr>
<tr class=' module-item'>
<td><a class="struct" href="struct.QueryPlanStep.html"
title='struct mentat_transaction::query::QueryPlanStep'>QueryPlanStep</a></td>
<td class='docblock-short'>
<p>A single row in the output of SQLite's <code>EXPLAIN QUERY PLAN</code>.
See https://www.sqlite.org/eqp.html for an explanation of each field.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="struct" href="struct.RelResult.html"
title='struct mentat_transaction::query::RelResult'>RelResult</a></td>
<td class='docblock-short'>
<p>The result you get from a 'rel' query, like:</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="struct" href="struct.Variable.html"
title='struct mentat_transaction::query::Variable'>Variable</a></td>
<td class='docblock-short'>
</td>
</tr></table><h2 id='enums' class='section-header'><a href="#enums">Enums</a></h2>
<table>
<tr class=' module-item'>
<td><a class="enum" href="enum.PreparedQuery.html"
title='enum mentat_transaction::query::PreparedQuery'>PreparedQuery</a></td>
<td class='docblock-short'>
</td>
</tr>
<tr class=' module-item'>
<td><a class="enum" href="enum.QueryExplanation.html"
title='enum mentat_transaction::query::QueryExplanation'>QueryExplanation</a></td>
<td class='docblock-short'>
<p>A struct describing information about how Mentat would execute a query.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="enum" href="enum.QueryResults.html"
title='enum mentat_transaction::query::QueryResults'>QueryResults</a></td>
<td class='docblock-short'>
</td>
</tr></table><h2 id='traits' class='section-header'><a href="#traits">Traits</a></h2>
<table>
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<td><a class="trait" href="trait.IntoResult.html"
title='trait mentat_transaction::query::IntoResult'>IntoResult</a></td>
<td class='docblock-short'>
</td>
</tr></table><h2 id='functions' class='section-header'><a href="#functions">Functions</a></h2>
<table>
<tr class=' module-item'>
<td><a class="fn" href="fn.lookup_value.html"
title='fn mentat_transaction::query::lookup_value'>lookup_value</a></td>
<td class='docblock-short'>
<p>Return a single value for the provided entity and attribute.
If the attribute is multi-valued, an arbitrary value is returned.
If no value is present for that entity, <code>None</code> is returned.
If <code>attribute</code> isn't an attribute, <code>None</code> is returned.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="fn" href="fn.lookup_value_for_attribute.html"
title='fn mentat_transaction::query::lookup_value_for_attribute'>lookup_value_for_attribute</a></td>
<td class='docblock-short'>
<p>Return a single value for the provided entity and attribute.
If the attribute is multi-valued, an arbitrary value is returned.
If no value is present for that entity, <code>None</code> is returned.
If <code>attribute</code> doesn't name an attribute, an error is returned.</p>
</td>
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<td><a class="fn" href="fn.lookup_values.html"
title='fn mentat_transaction::query::lookup_values'>lookup_values</a></td>
<td class='docblock-short'>
</td>
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<tr class=' module-item'>
<td><a class="fn" href="fn.lookup_values_for_attribute.html"
title='fn mentat_transaction::query::lookup_values_for_attribute'>lookup_values_for_attribute</a></td>
<td class='docblock-short'>
</td>
</tr>
<tr class=' module-item'>
<td><a class="fn" href="fn.q_explain.html"
title='fn mentat_transaction::query::q_explain'>q_explain</a></td>
<td class='docblock-short'>
</td>
</tr>
<tr class=' module-item'>
<td><a class="fn" href="fn.q_once.html"
title='fn mentat_transaction::query::q_once'>q_once</a></td>
<td class='docblock-short'>
<p>Take an EDN query string, a reference to an open SQLite connection, a Mentat schema, and an
optional collection of input bindings (which should be keyed by <code>&quot;?varname&quot;</code>), and execute the
query immediately, blocking the current thread.
Returns a structure that corresponds to the kind of input query, populated with <code>TypedValue</code>
instances.
The caller is responsible for ensuring that the SQLite connection has an open transaction if
isolation is required.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="fn" href="fn.q_prepare.html"
title='fn mentat_transaction::query::q_prepare'>q_prepare</a></td>
<td class='docblock-short'>
</td>
</tr>
<tr class=' module-item'>
<td><a class="fn" href="fn.q_uncached.html"
title='fn mentat_transaction::query::q_uncached'>q_uncached</a></td>
<td class='docblock-short'>
<p>Just like <code>q_once</code>, but doesn't use any cached values.</p>
</td>
</tr></table><h2 id='types' class='section-header'><a href="#types">Type Definitions</a></h2>
<table>
<tr class=' module-item'>
<td><a class="type" href="type.PreparedResult.html"
title='type mentat_transaction::query::PreparedResult'>PreparedResult</a></td>
<td class='docblock-short'>
</td>
</tr>
<tr class=' module-item'>
<td><a class="type" href="type.QueryExecutionResult.html"
title='type mentat_transaction::query::QueryExecutionResult'>QueryExecutionResult</a></td>
<td class='docblock-short'>
</td>
</tr></table></section>
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