fix(DatabaseController): Do not match any entry when searching for null in relation field (#3924)

src/Adapters/Storage/Postgres/PostgresStorageAdapter.js

@@ -188,7 +188,7 @@ const buildWhereClause = ({ schema, query, index }) => {
     // nothingin the schema, it's gonna blow up
     if (!schema.fields[fieldName]) {
       // as it won't exist
-      if (fieldValue.$exists === false) {
+      if (fieldValue && fieldValue.$exists === false) {
         continue;
       }
     }
@@ -202,7 +202,16 @@ const buildWhereClause = ({ schema, query, index }) => {
       });
       let name = components.slice(0, components.length - 1).join('->');
       name += '->>' + components[components.length - 1];
-      patterns.push(`${name} = '${fieldValue}'`);
+      if (fieldValue === null) {
+        patterns.push(`${name} IS NULL`);
+      } else {
+        patterns.push(`${name} = '${fieldValue}'`);
+      }
+    } else if (fieldValue === null) {
+      patterns.push(`$${index}:name IS NULL`);
+      values.push(fieldName);
+      index += 1;
+      continue;
     } else if (typeof fieldValue === 'string') {
       patterns.push(`$${index}:name = $${index + 1}`);
       values.push(fieldName, fieldValue);
@@ -231,13 +240,16 @@ const buildWhereClause = ({ schema, query, index }) => {
       values.push(...clauseValues);
     }
 
-    if (fieldValue.$ne) {
+    if (fieldValue.$ne !== undefined) {
       if (isArrayField) {
         fieldValue.$ne = JSON.stringify([fieldValue.$ne]);
         patterns.push(`NOT array_contains($${index}:name, $${index + 1})`);
       } else {
         if (fieldValue.$ne === null) {
-          patterns.push(`$${index}:name <> $${index + 1}`);
+          patterns.push(`$${index}:name IS NOT NULL`);
+          values.push(fieldName);
+          index += 1;
+          continue;
         } else {
           // if not null, we need to manually exclude null
           patterns.push(`($${index}:name <> $${index + 1} OR $${index}:name IS NULL)`);
@@ -764,6 +776,9 @@ export class PostgresStorageAdapter {
     validateKeys(object);
 
     Object.keys(object).forEach(fieldName => {
+      if (object[fieldName] === null) {
+        return;
+      }
       var authDataMatch = fieldName.match(/^_auth_data_([a-zA-Z0-9_]+)$/);
       if (authDataMatch) {
         var provider = authDataMatch[1];

src/Controllers/DatabaseController.js

@@ -616,13 +616,14 @@ DatabaseController.prototype.reduceInRelation = function(className, query, schem
   }
 
   const promises = Object.keys(query).map((key) => {
+    const t = schema.getExpectedType(className, key);
+    if (!t || t.type !== 'Relation') {
+      return Promise.resolve(query);
+    }
+    let queries = null;
     if (query[key] && (query[key]['$in'] || query[key]['$ne'] || query[key]['$nin'] || query[key].__type == 'Pointer')) {
-      const t = schema.getExpectedType(className, key);
-      if (!t || t.type !== 'Relation') {
-        return Promise.resolve(query);
-      }
       // Build the list of queries
-      const queries = Object.keys(query[key]).map((constraintKey) => {
+      queries = Object.keys(query[key]).map((constraintKey) => {
         let relatedIds;
         let isNegation = false;
         if (constraintKey === 'objectId') {
@@ -643,31 +644,32 @@ DatabaseController.prototype.reduceInRelation = function(className, query, schem
           relatedIds
         }
       });
-
-      // remove the current queryKey as we don,t need it anymore
-      delete query[key];
-      // execute each query independnently to build the list of
-      // $in / $nin
-      const promises = queries.map((q) => {
-        if (!q) {
-          return Promise.resolve();
-        }
-        return this.owningIds(className, key, q.relatedIds).then((ids) => {
-          if (q.isNegation) {
-            this.addNotInObjectIdsIds(ids, query);
-          } else {
-            this.addInObjectIdsIds(ids, query);
-          }
-          return Promise.resolve();
-        });
-      });
-
-      return Promise.all(promises).then(() => {
-        return Promise.resolve();
-      })
-
+    } else {
+      queries = [{isNegation: false, relatedIds: []}];
     }
-    return Promise.resolve();
+
+    // remove the current queryKey as we don,t need it anymore
+    delete query[key];
+    // execute each query independnently to build the list of
+    // $in / $nin
+    const promises = queries.map((q) => {
+      if (!q) {
+        return Promise.resolve();
+      }
+      return this.owningIds(className, key, q.relatedIds).then((ids) => {
+        if (q.isNegation) {
+          this.addNotInObjectIdsIds(ids, query);
+        } else {
+          this.addInObjectIdsIds(ids, query);
+        }
+        return Promise.resolve();
+      });
+    });
+
+    return Promise.all(promises).then(() => {
+      return Promise.resolve();
+    })
+
   })
 
   return Promise.all(promises).then(() => {