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<p class='location'>Struct CombinedProjection</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#fields">Fields</a><div class="sidebar-links"><a href="#structfield.sql_projection">sql_projection</a><a href="#structfield.pre_aggregate_projection">pre_aggregate_projection</a><a href="#structfield.datalog_projector">datalog_projector</a><a href="#structfield.distinct">distinct</a><a href="#structfield.group_by_cols">group_by_cols</a></div></div><p class='location'><a href='index.html'>mentat_query_projector</a></p><script>window.sidebarCurrent = {name: 'CombinedProjection', ty: 'struct', relpath: ''};</script><script defer src="sidebar-items.js"></script></div>
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<h1 class='fqn'><span class='in-band'>Struct <a href='index.html'>mentat_query_projector</a>::<wbr><a class="struct" href=''>CombinedProjection</a></span><span class='out-of-band'><span id='render-detail'>
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</span><a class='srclink' href='../src/mentat_query_projector/lib.rs.html#392-416' title='goto source code'>[src]</a></span></h1>
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<pre class='rust struct'>pub struct CombinedProjection {
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pub sql_projection: <a class="enum" href="../mentat_query_sql/enum.Projection.html" title="enum mentat_query_sql::Projection">Projection</a>,
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pub pre_aggregate_projection: <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><<a class="enum" href="../mentat_query_sql/enum.Projection.html" title="enum mentat_query_sql::Projection">Projection</a>>,
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pub datalog_projector: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/boxed/struct.Box.html" title="struct alloc::boxed::Box">Box</a><<a class="trait" href="../mentat_query_projector/trait.Projector.html" title="trait mentat_query_projector::Projector">Projector</a>>,
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pub distinct: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a>,
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pub group_by_cols: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/vec/struct.Vec.html" title="struct alloc::vec::Vec">Vec</a><<a class="enum" href="../mentat_query_sql/enum.GroupBy.html" title="enum mentat_query_sql::GroupBy">GroupBy</a>>,
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}</pre><div class='docblock'><p>Combines the things you need to turn a query into SQL and turn its results into
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<code>QueryResults</code>: SQL-related projection information (<code>DISTINCT</code>, columns, etc.) and
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a Datalog projector that turns SQL into structures.</p>
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</div><h2 id='fields' class='fields small-section-header'>
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Fields<a href='#fields' class='anchor'></a></h2><span id="structfield.sql_projection" class="structfield small-section-header">
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<a href="#structfield.sql_projection" class="anchor field"></a>
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<span id="sql_projection.v" class='invisible'>
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<code>sql_projection: <a class="enum" href="../mentat_query_sql/enum.Projection.html" title="enum mentat_query_sql::Projection">Projection</a></code>
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</span></span><div class='docblock'><p>A SQL projection, mapping columns mentioned in the body of the query to columns in the
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output.</p>
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</div><span id="structfield.pre_aggregate_projection" class="structfield small-section-header">
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<a href="#structfield.pre_aggregate_projection" class="anchor field"></a>
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<span id="pre_aggregate_projection.v" class='invisible'>
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<code>pre_aggregate_projection: <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><<a class="enum" href="../mentat_query_sql/enum.Projection.html" title="enum mentat_query_sql::Projection">Projection</a>></code>
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</span></span><div class='docblock'><p>If a query contains aggregates, we need to generate a nested subquery: an inner query
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that returns our distinct variable bindings (and any <code>:with</code> vars), and an outer query
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that applies aggregation. That's so we can put <code>DISTINCT</code> in the inner query and apply
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aggregation afterwards -- <code>SELECT DISTINCT count(foo)</code> counts <em>then</em> uniques, and we need
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the opposite to implement Datalog distinct semantics.
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If this is the case, <code>sql_projection</code> will be the outer query's projection list, and
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<code>pre_aggregate_projection</code> will be the inner.
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If the query doesn't use aggregation, this field will be <code>None</code>.</p>
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</div><span id="structfield.datalog_projector" class="structfield small-section-header">
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<code>datalog_projector: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/boxed/struct.Box.html" title="struct alloc::boxed::Box">Box</a><<a class="trait" href="../mentat_query_projector/trait.Projector.html" title="trait mentat_query_projector::Projector">Projector</a>></code>
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</span></span><div class='docblock'><p>A Datalog projection. This consumes rows of the appropriate shape (as defined by
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the SQL projection) to yield one of the four kinds of Datalog query result.</p>
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<code>distinct: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code>
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</span></span><div class='docblock'><p>True if this query requires the SQL query to include DISTINCT.</p>
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</div><span id="structfield.group_by_cols" class="structfield small-section-header">
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<code>group_by_cols: <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/vec/struct.Vec.html" title="struct alloc::vec::Vec">Vec</a><<a class="enum" href="../mentat_query_sql/enum.GroupBy.html" title="enum mentat_query_sql::GroupBy">GroupBy</a>></code>
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