arangodb/Documentation/Examples/ensureUniqueConstraint.generated

arangosh&gt; db.test.ensureIndex({ <span class="hljs-attr">type</span>: <span class="hljs-string">"hash"</span>, <span class="hljs-attr">fields</span>: [ <span class="hljs-string">"a"</span>, <span class="hljs-string">"b.c"</span> ], <span class="hljs-attr">unique</span>: <span class="hljs-literal">true</span> });
{ 
  <span class="hljs-string">"deduplicate"</span> : <span class="hljs-literal">true</span>, 
  <span class="hljs-string">"fields"</span> : [ 
    <span class="hljs-string">"a"</span>, 
    <span class="hljs-string">"b.c"</span> 
  ], 
  <span class="hljs-string">"id"</span> : <span class="hljs-string">"test/17536"</span>, 
  <span class="hljs-string">"isNewlyCreated"</span> : <span class="hljs-literal">true</span>, 
  <span class="hljs-string">"selectivityEstimate"</span> : <span class="hljs-number">1</span>, 
  <span class="hljs-string">"sparse"</span> : <span class="hljs-literal">false</span>, 
  <span class="hljs-string">"type"</span> : <span class="hljs-string">"hash"</span>, 
  <span class="hljs-string">"unique"</span> : <span class="hljs-literal">true</span>, 
  <span class="hljs-string">"code"</span> : <span class="hljs-number">201</span> 
}
arangosh&gt; db.test.save({ <span class="hljs-attr">a</span> : <span class="hljs-number">1</span>, <span class="hljs-attr">b</span> : { <span class="hljs-attr">c</span> : <span class="hljs-number">1</span> } });
{ 
  <span class="hljs-string">"_id"</span> : <span class="hljs-string">"test/17539"</span>, 
  <span class="hljs-string">"_key"</span> : <span class="hljs-string">"17539"</span>, 
  <span class="hljs-string">"_rev"</span> : <span class="hljs-string">"_VvTSF2y---"</span> 
}
arangosh&gt; db.test.save({ <span class="hljs-attr">a</span> : <span class="hljs-number">1</span>, <span class="hljs-attr">b</span> : { <span class="hljs-attr">c</span> : <span class="hljs-number">1</span> } });
[ArangoError <span class="hljs-number">1210</span>: unique constraint violated - <span class="hljs-keyword">in</span> index <span class="hljs-number">17536</span> <span class="hljs-keyword">of</span> type hash over [<span class="hljs-string">"a"</span>,<span class="hljs-string">"b.c"</span>]]
arangosh&gt; db.test.save({ <span class="hljs-attr">a</span> : <span class="hljs-number">1</span>, <span class="hljs-attr">b</span> : { <span class="hljs-attr">c</span> : <span class="hljs-literal">null</span> } });
{ 
  <span class="hljs-string">"_id"</span> : <span class="hljs-string">"test/17545"</span>, 
  <span class="hljs-string">"_key"</span> : <span class="hljs-string">"17545"</span>, 
  <span class="hljs-string">"_rev"</span> : <span class="hljs-string">"_VvTSF22---"</span> 
}
arangosh&gt; db.test.save({ <span class="hljs-attr">a</span> : <span class="hljs-number">1</span> });
[ArangoError <span class="hljs-number">1210</span>: unique constraint violated - <span class="hljs-keyword">in</span> index <span class="hljs-number">17536</span> <span class="hljs-keyword">of</span> type hash over [<span class="hljs-string">"a"</span>,<span class="hljs-string">"b.c"</span>]]