feat(ESCatalog): Add support for pushing down null predicates to elastic

kuseman · Sep 12, 2024 · 3addd21 · 3addd21
1 parent b50d99b
commit 3addd21
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diff --git a/payloadbuilder-api/src/test/java/se/kuseman/payloadbuilder/test/IPredicateMock.java b/payloadbuilder-api/src/test/java/se/kuseman/payloadbuilder/test/IPredicateMock.java
@@ -23,6 +23,7 @@
 import se.kuseman.payloadbuilder.api.expression.IFunctionCallExpression;
 import se.kuseman.payloadbuilder.api.expression.IInExpression;
 import se.kuseman.payloadbuilder.api.expression.ILikeExpression;
+import se.kuseman.payloadbuilder.api.expression.INullPredicateExpression;
 
 /** Helper class for mocking {@link IAnalyzePair}'s */
 public class IPredicateMock
@@ -81,6 +82,19 @@ public static IPredicate notIn(String column, List<Object> values)
         return inPair(column, true, values);
     }
 
+    public static IPredicate _null(String column, boolean not)
+    {
+        IPredicate pair = mock(IPredicate.class);
+        when(pair.getQualifiedColumn()).thenReturn(QualifiedName.of(column));
+        when(pair.getType()).thenReturn(IPredicate.Type.NULL);
+
+        INullPredicateExpression expression = mock(INullPredicateExpression.class);
+
+        when(pair.getNullPredicateExpression()).thenReturn(expression);
+        when(expression.isNot()).thenReturn(not);
+        return pair;
+    }
+
     /** Mock an IN pair */
     public static IPredicate inPair(String column, boolean not, List<Object> values)
     {

diff --git a/...builder-catalog/src/main/java/se/kuseman/payloadbuilder/catalog/es/PropertyPredicate.java b/...builder-catalog/src/main/java/se/kuseman/payloadbuilder/catalog/es/PropertyPredicate.java
@@ -25,6 +25,7 @@
 import se.kuseman.payloadbuilder.api.expression.IFunctionCallExpression;
 import se.kuseman.payloadbuilder.api.expression.IInExpression;
 import se.kuseman.payloadbuilder.api.expression.ILikeExpression;
+import se.kuseman.payloadbuilder.api.expression.INullPredicateExpression;
 
 /** Predicate for a property */
 @SuppressWarnings("deprecation")
@@ -160,6 +161,48 @@ else if (predicate.getType() == IPredicate.Type.LIKE)
                     .append("}}}");
             appendNested(sb);
         }
+        else if (predicate.getType() == Type.NULL)
+        {
+            INullPredicateExpression nullExpression = predicate.getNullPredicateExpression();
+
+            //@formatter:off
+            // Elasticsearch ignore null values and these cannot be searched/filtered which means
+            // that we can use exists for null predicate. If a field exists in a document that field cannot be null
+            // which in turn means that if a field does not exists on a document it must be null
+            // IS NULL
+            //
+            // "bool": {
+            //    "must_not": [
+            //      {
+            //        "exists": {
+            //          "field": <field>
+            //        }
+            //      }
+            //    ]
+            // }
+            //
+            // IS NOT NULL
+            // "bool": {
+            //    "filter": [
+            //      {
+            //        "exists": {
+            //          "field": <field>
+            //        }
+            //      }
+            //    ]
+            // }
+            //@formatter:on
+
+            // NOTE!
+            // IS NOT NULL -> must
+            // IS NULL -> must_not
+            StringBuilder sb = nullExpression.isNot() ? filterMust
+                    : filterMustNot;
+
+            sb.append("{\"exists\":{\"field\":\"")
+                    .append(property)
+                    .append("\"}}");
+        }
         else if (fullTextPredicate)
         {
             appendFullTextOperator(describe, context, predicate.getFunctionCallExpression(), filterMust);
@@ -294,6 +337,7 @@ static boolean isSupported(IPredicate predicate, String catalogAlias)
     {
         IPredicate.Type type = predicate.getType();
         return type == Type.COMPARISION
+                || type == Type.NULL
                 || (type == Type.FUNCTION_CALL
                         && isFullTextSearchPredicate(predicate.getFunctionCallExpression(), catalogAlias))
                 || type == Type.IN

diff --git a/...dbuilder-catalog/src/test/java/se/kuseman/payloadbuilder/catalog/es/ESQueryUtilsTest.java b/...dbuilder-catalog/src/test/java/se/kuseman/payloadbuilder/catalog/es/ESQueryUtilsTest.java
@@ -220,6 +220,13 @@ public void test_search_body_singleType()
                 ESQueryUtils.getSearchBody(false, new GenericStrategy(), emptyList(), pairs.stream()
                         .map(p -> new PropertyPredicate("", p, true))
                         .collect(toList()), null, null, false, context));
+
+        pairs = asList(IPredicateMock._null("field1", false), IPredicateMock._null("field2", true));
+        assertEquals("{\"sort\":[\"_doc\"],\"query\":{\"bool\":{\"filter\":[{\"exists\":{\"field\":\"field2\"}}],\"must_not\":[{\"exists\":{\"field\":\"field1\"}}]}}}",
+                ESQueryUtils.getSearchBody(false, new GenericStrategy(), emptyList(), pairs.stream()
+                        .map(p -> new PropertyPredicate(p.getQualifiedColumn()
+                                .toString(), p, false))
+                        .collect(toList()), null, null, false, context));
     }
 
     @Test
@@ -318,6 +325,13 @@ public void test_search_body()
                 ESQueryUtils.getSearchBody(false, new Elastic1XStrategy(), emptyList(), pairs.stream()
                         .map(p -> new PropertyPredicate("", p, true))
                         .collect(toList()), null, null, false, context));
+
+        pairs = asList(IPredicateMock._null("field1", false), IPredicateMock._null("field2", true));
+        assertEquals("{\"sort\":[\"_doc\"],\"filter\":{\"bool\":{\"must\":[{\"exists\":{\"field\":\"field2\"}}],\"must_not\":[{\"exists\":{\"field\":\"field1\"}}]}}}",
+                ESQueryUtils.getSearchBody(false, new Elastic1XStrategy(), emptyList(), pairs.stream()
+                        .map(p -> new PropertyPredicate(p.getQualifiedColumn()
+                                .toString(), p, false))
+                        .collect(toList()), null, null, false, context));
     }
 
     private List<IPredicate> getMockPairs()