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<li class="toctree-l1 current"><a class="current reference internal" href="#">Scalar Functions</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#id">id</a></li>
<li class="toctree-l2"><a class="reference internal" href="#start-id">start_id</a></li>
<li class="toctree-l2"><a class="reference internal" href="#end-id">end_id</a></li>
<li class="toctree-l2"><a class="reference internal" href="#type">type</a></li>
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<li class="toctree-l2"><a class="reference internal" href="#head">head</a></li>
<li class="toctree-l2"><a class="reference internal" href="#last">last</a></li>
<li class="toctree-l2"><a class="reference internal" href="#length">length</a></li>
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<li class="toctree-l2"><a class="reference internal" href="#startnode">startNode</a></li>
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<section id="scalar-functions">
<h1>Scalar Functions<a class="headerlink" href="#scalar-functions" title="Permalink to this heading"></a></h1>
<section id="id">
<h2>id<a class="headerlink" href="#id" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">id()</span></code> returns the id of a vertex or edge.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">id(expression)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">integer</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>expression
</td>
<td>An expression that returns a vertex or edge.
</td>
</tr>
</table>
<p>Considerations:</p>
<p>Query:</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH (a)</span>
<span class="s"> RETURN id(a)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">id</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Results</p>
<table>
<tr>
<td>id
</td>
</tr>
<tr>
<td>0
</td>
</tr>
<tr>
<td>1
</td>
</tr>
<tr>
<td>2
</td>
</tr>
<tr>
<td>3
</td>
</tr>
<tr>
<td>4 row(s) returned
</td>
</tr>
</table>
</section>
<section id="start-id">
<h2>start_id<a class="headerlink" href="#start-id" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">start_id()</span></code> returns the id of the vertex that is the starting vertex for the edge.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">start_id(expression)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">integer</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>expression
</td>
<td>An expression that evaluates to an edge.
</td>
</tr>
</table>
<p>Considerations:</p>
<p>Query:</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH ()-[e]-&gt;()</span>
<span class="s"> RETURN start_id(e)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">start_id</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Results</p>
<table>
<tr>
<td>start_id
</td>
</tr>
<tr>
<td>0
</td>
</tr>
<tr>
<td>1
</td>
</tr>
<tr>
<td>2
</td>
</tr>
<tr>
<td>3
</td>
</tr>
<tr>
<td>4 row(s) returned
</td>
</tr>
</table>
</section>
<section id="end-id">
<h2>end_id<a class="headerlink" href="#end-id" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">end_id()</span></code> returns the id of the vertex that is the ending vertex for the edge.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">end_id(expression)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">integer</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>expression
</td>
<td>An expression that evaluates to an edge.
</td>
</tr>
</table>
<p>Query:</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH ()-[e]-&gt;()</span>
<span class="s"> RETURN end_id(e)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">end_id</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Results</p>
<table>
<tr>
<td>end_id
</td>
</tr>
<tr>
<td>4
</td>
</tr>
<tr>
<td>5
</td>
</tr>
<tr>
<td>6
</td>
</tr>
<tr>
<td>7
</td>
</tr>
<tr>
<td>4 row(s) returned
</td>
</tr>
</table>
</section>
<section id="type">
<h2>type<a class="headerlink" href="#type" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">type()</span></code> returns the string representation of the edge type.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">type(edge)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">string</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>edge
</td>
<td>An expression that evaluates to an edge.
</td>
</tr>
</table>
<p>Considerations:</p>
<p>Query:</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH ()-[e]-&gt;()</span>
<span class="s"> RETURN type(e)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="k">type</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Results</p>
<table>
<tr>
<td>type
</td>
</tr>
<tr>
<td>“KNOWS”
</td>
</tr>
<tr>
<td>“KNOWS”
</td>
</tr>
<tr>
<td>2 row(s) returned
</td>
</tr>
</table>
</section>
<section id="properties">
<h2>properties<a class="headerlink" href="#properties" title="Permalink to this heading"></a></h2>
<p>Returns an agtype map containing all the properties of a vertex or edge. If the argument is already a map, it is returned unchanged.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">properties(expression)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="nb">map</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>Expression
</td>
<td>An expression that returns a vertex, an edge, or an agtype map.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">properties(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
</ul>
<p>Query:</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> CREATE (p:Person {name: &#39;Stefan&#39;, city: &#39;Berlin&#39;})</span>
<span class="s"> RETURN properties(p)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="k">type</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Results:</p>
<table>
<tr>
<td><strong>properties</strong>
</td>
</tr>
<tr>
<td>{name: "Stefan"; city: "Berlin"}
</td>
</tr>
<tr>
<td>1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="head">
<h2>head<a class="headerlink" href="#head" title="Permalink to this heading"></a></h2>
<p>returns the first element in an agtype list.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">head(list)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">The</span> <span class="nb">type</span> <span class="n">of</span> <span class="n">the</span> <span class="n">value</span> <span class="n">returned</span> <span class="n">will</span> <span class="n">be</span> <span class="n">that</span> <span class="n">of</span> <span class="n">the</span> <span class="n">first</span> <span class="n">element</span> <span class="n">of</span> <span class="n">the</span> <span class="nb">list</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>List
</td>
<td>An expression that returns a list
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">head(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
<li><p>If the first element in the list is <code class="docutils literal notranslate"><span class="pre">null</span></code>, <code class="docutils literal notranslate"><span class="pre">head(list)</span></code> will return <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH (a)</span>
<span class="s"> WHERE a.name = &#39;Eskil&#39;</span>
<span class="s"> RETURN a.array, head(a.array)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">lst</span><span class="w"> </span><span class="n">agtype</span><span class="p">,</span><span class="w"> </span><span class="n">lst_head</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>The first element in the list is returned.</p>
<p>Result:</p>
<table>
<tr>
<td>lst
</td>
<td>lst_head
</td>
</tr>
<tr>
<td>["one","two","three"]
</td>
<td>"one"
</td>
</tr>
<tr>
<td colspan="2" >1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="last">
<h2>last<a class="headerlink" href="#last" title="Permalink to this heading"></a></h2>
<p>returns the last element in an agtype list.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">last(list)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">The</span> <span class="nb">type</span> <span class="n">of</span> <span class="n">the</span> <span class="n">value</span> <span class="n">returned</span> <span class="n">will</span> <span class="n">be</span> <span class="n">that</span> <span class="n">of</span> <span class="n">the</span> <span class="n">last</span> <span class="n">element</span> <span class="n">of</span> <span class="n">the</span> <span class="nb">list</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>List
</td>
<td>An expression that returns a list
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">tail(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
<li><p>If the last element in the list is <code class="docutils literal notranslate"><span class="pre">null</span></code>, <code class="docutils literal notranslate"><span class="pre">last(list)</span></code> will return <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s">MATCH (a)</span>
<span class="s">WHERE a.name = &#39;Eskil&#39;</span>
<span class="s">RETURN a.array, last(a.array)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">lst</span><span class="w"> </span><span class="n">agtype</span><span class="p">,</span><span class="w"> </span><span class="n">lst_tail</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>The first element in the list is returned.</p>
<p>Result:</p>
<table>
<tr>
<td>lst
</td>
<td>lst_tail
</td>
</tr>
<tr>
<td>["one","two","three"]
</td>
<td>"three"
</td>
</tr>
<tr>
<td colspan="2" >1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="length">
<h2>length<a class="headerlink" href="#length" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">length()</span></code> returns the length of a path.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">length(path)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">integer</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>path
</td>
<td>An expression that returns a path.
</td>
</tr>
</table>
<p>Considerations: <code class="docutils literal notranslate"><span class="pre">length(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH p = (a)-[]-&gt;(b)-[]-&gt;(c)</span>
<span class="s"> WHERE a.name = &#39;Alice&#39;</span>
<span class="s"> RETURN length(p)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">length_of_path</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>The length of the path <code class="docutils literal notranslate"><span class="pre">p</span></code> is returned.</p>
<p>Results:</p>
<table>
<tr>
<td>length_of_path
</td>
</tr>
<tr>
<td>2
</td>
</tr>
<tr>
<td>2
</td>
</tr>
<tr>
<td>2
</td>
</tr>
<tr>
<td>3 row(s) returned
</td>
</tr>
</table>
</section>
<section id="size">
<h2>size<a class="headerlink" href="#size" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">size()</span></code> returns the length of a list.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">size(list)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">integer</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>list
</td>
<td>An expression that returns a list.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">size(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> RETURN size([&#39;Alice&#39;, &#39;Bob&#39;])</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">size_of_list</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>The length of the path <code class="docutils literal notranslate"><span class="pre">p</span></code> is returned.</p>
<p>Results:</p>
<table>
<tr>
<td>size_of_list
</td>
</tr>
<tr>
<td>2
</td>
</tr>
<tr>
<td>1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="startnode">
<h2>startNode<a class="headerlink" href="#startnode" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">startNode()</span></code> returns the start node of an edge.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">startNode(edge)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">A</span> <span class="n">vertex</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>edge
</td>
<td>An expression that returns an edge.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">startNode(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH (x:Developer)-[r]-()</span>
<span class="s"> RETURN startNode(r)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">v</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Result</p>
<table>
<tr>
<td>v
</td>
</tr>
<tr>
<td>Node[0]{name:"Alice",age:38,eyes:"brown"}
</td>
</tr>
<tr>
<td>Node[0]{name:"Alice",age:38,eyes:"brown"}
</td>
</tr>
<tr>
<td>2 row(s) returned
</td>
</tr>
</table>
</section>
<section id="endnode">
<h2>endNode<a class="headerlink" href="#endnode" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">endNode()</span></code> returns the start node of an edge.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">endNode(edge)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">A</span> <span class="n">vertex</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>edge
</td>
<td>An expression that returns an edge.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">endNode(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> MATCH (x:Developer)-[r]-()</span>
<span class="s"> RETURN endNode(r)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">v</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Result</p>
<table>
<tr>
<td>v
</td>
</tr>
<tr>
<td>Node[2]{name:"Charlie",age:53,eyes:"green"}
</td>
</tr>
<tr>
<td>Node[1]{name:"Bob",age:25,eyes:"blue"}
</td>
</tr>
<tr>
<td>2 row(s) returned
</td>
</tr>
</table>
</section>
<section id="timestamp">
<h2>timestamp<a class="headerlink" href="#timestamp" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">timestamp()</span></code> returns the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">timestamp()</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">integer</span><span class="o">.</span>
</pre></div>
</div>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">timestamp()</span></code> will return the same value during one entire query, even for long-running queries.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> RETURN timestamp()</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">t</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>The time in milliseconds is returned.</p>
<p>Results:</p>
<table>
<tr>
<td><strong>t</strong>
</td>
</tr>
<tr>
<td>1613496720760
</td>
</tr>
<tr>
<td>1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="toboolean">
<h2>toBoolean<a class="headerlink" href="#toboolean" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">toBoolean()</span></code> converts a string value to a boolean value.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">toBoolean(expression)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">boolean</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td><strong>Name</strong>
</td>
<td><strong>Description</strong>
</td>
</tr>
<tr>
<td>expression
</td>
<td>An expression that returns a boolean or string value.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">toBoolean(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
<li><p>If expression is a boolean value, it will be returned unchanged.</p></li>
<li><p>If the parsing fails, <code class="docutils literal notranslate"><span class="pre">null</span></code> will be returned.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> RETURN toBoolean(&#39;TRUE&#39;), toBoolean(&#39;not a boolean&#39;)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">a_bool</span><span class="w"> </span><span class="n">agtype</span><span class="p">,</span><span class="w"> </span><span class="n">not_a_bool</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Result:</p>
<table>
<tr>
<td><strong>a_bool</strong>
</td>
<td><strong>not_a_bool</strong>
</td>
</tr>
<tr>
<td>true
</td>
<td>NULL
</td>
</tr>
<tr>
<td colspan="2" >1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="tofloat">
<h2>toFloat<a class="headerlink" href="#tofloat" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">toFloat()</span></code> converts an integer or string value to a floating point number.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">toFloat(expression)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">A</span> <span class="nb">float</span><span class="o">.</span>
</pre></div>
</div>
<table>
<tr>
<td><strong>Name</strong>
</td>
<td><strong>Description</strong>
</td>
</tr>
<tr>
<td>expression
</td>
<td>An expression that returns an agtype number or agtype string value.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">toFloat(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
<li><p>If expression is a floating point number, it will be returned unchanged.</p></li>
<li><p>If the parsing fails, <code class="docutils literal notranslate"><span class="pre">null</span></code> will be returned.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> RETURN toFloat(&#39;11.5&#39;), toFloat(&#39;not a number&#39;)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">a_float</span><span class="w"> </span><span class="n">agtype</span><span class="p">,</span><span class="w"> </span><span class="n">not_a_float</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Result:</p>
<table>
<tr>
<td>a_float
</td>
<td>not_a_float
</td>
</tr>
<tr>
<td>11.5
</td>
<td>NULL
</td>
</tr>
<tr>
<td colspan="2" >1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="tointeger">
<h2>toInteger<a class="headerlink" href="#tointeger" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">toInteger()</span></code> converts a floating point or string value to an integer value.</p>
<p>Syntax: <code class="docutils literal notranslate"><span class="pre">toInteger(expression)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">An</span> <span class="n">agtype</span> <span class="n">integer</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments</p>
<table>
<tr>
<td><strong>Name</strong>
</td>
<td><strong>Description</strong>
</td>
</tr>
<tr>
<td>expression
</td>
<td>An expression that returns an agtype number or agtype string value.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">toInteger(null)</span></code> returns <code class="docutils literal notranslate"><span class="pre">null</span></code>.</p></li>
<li><p>If expression is an integer value, it will be returned unchanged.</p></li>
<li><p>If the parsing fails, <code class="docutils literal notranslate"><span class="pre">null</span></code> will be returned.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s"> RETURN toInteger(&#39;42&#39;), toInteger(&#39;not a number&#39;)</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">an_integer</span><span class="w"> </span><span class="n">agtype</span><span class="p">,</span><span class="w"> </span><span class="n">not_an_integer</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Result:</p>
<table>
<tr>
<td>an_integer
</td>
<td>not_an_integer
</td>
</tr>
<tr>
<td>42
</td>
<td>NULL
</td>
</tr>
<tr>
<td colspan="2" >1 row(s) returned
</td>
</tr>
</table>
</section>
<section id="coalesce">
<h2>coalesce<a class="headerlink" href="#coalesce" title="Permalink to this heading"></a></h2>
<p><code class="docutils literal notranslate"><span class="pre">coalesce()</span></code> returns the first non-null value in the given list of expressions.</p>
<p>Syntax:<code class="docutils literal notranslate"><span class="pre">coalesce(expression</span> <span class="pre">[,</span> <span class="pre">expression]*)</span></code></p>
<p>Returns:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">The</span> <span class="nb">type</span> <span class="n">of</span> <span class="n">the</span> <span class="n">value</span> <span class="n">returned</span> <span class="n">will</span> <span class="n">be</span> <span class="n">that</span> <span class="n">of</span> <span class="n">the</span> <span class="n">first</span> <span class="n">non</span><span class="o">-</span><span class="n">null</span> <span class="n">expression</span><span class="o">.</span>
</pre></div>
</div>
<p>Arguments:</p>
<table>
<tr>
<td>Name
</td>
<td>Description
</td>
</tr>
<tr>
<td>expression
</td>
<td>An expression which may return null.
</td>
</tr>
</table>
<p>Considerations:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">null</span></code> will be returned if all the arguments are null.</p></li>
</ul>
<p>Query</p>
<div class="highlight-postgresql notranslate"><div class="highlight"><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span>
<span class="k">FROM</span><span class="w"> </span><span class="n">cypher</span><span class="p">(</span><span class="s1">&#39;graph_name&#39;</span><span class="p">,</span><span class="w"> </span><span class="s">$$</span>
<span class="s">MATCH (a)</span>
<span class="s">WHERE a.name = &#39;Alice&#39;</span>
<span class="s">RETURN coalesce(a.hairColor, a.eyes), a.hair_color, a.eyes</span>
<span class="s">$$</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="p">(</span><span class="n">color</span><span class="w"> </span><span class="n">agtype</span><span class="p">,</span><span class="w"> </span><span class="n">hair_color</span><span class="w"> </span><span class="n">agtype</span><span class="p">,</span><span class="w"> </span><span class="n">eyes</span><span class="w"> </span><span class="n">agtype</span><span class="p">);</span>
</pre></div>
</div>
<p>Result</p>
<table>
<tr>
<td>color
</td>
<td>hair_color
</td>
<td>eyes
</td>
</tr>
<tr>
<td>“brown”
</td>
<td>NULL
</td>
<td>“Brown”
</td>
</tr>
<tr>
<td colspan="3" >1 row(s) returned
</td>
</tr>
</table>
</section>
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