Coral-Schema: Return nullable schema for inner RelDataType (#369)

linkedin · Mar 17, 2023 · 806b18e · 806b18e
1 parent 37f827e
commit 806b18e
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Showing 3 changed files with 4 additions and 8 deletions.
diff --git a/coral-schema/src/main/java/com/linkedin/coral/schema/avro/RelDataTypeToAvroType.java b/coral-schema/src/main/java/com/linkedin/coral/schema/avro/RelDataTypeToAvroType.java
@@ -6,7 +6,6 @@
 package com.linkedin.coral.schema.avro;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 
 import javax.annotation.Nonnull;
@@ -79,10 +78,7 @@ static Schema relDataTypeToAvroTypeNonNullable(@Nonnull RelDataType relDataType,
 
   private static Schema relDataTypeToAvroType(RelDataType relDataType, String recordName) {
     final Schema avroSchema = relDataTypeToAvroTypeNonNullable(relDataType, recordName);
-    if (relDataType.isNullable() && avroSchema.getType() != Schema.Type.NULL) {
-      return Schema.createUnion(Arrays.asList(Schema.create(Schema.Type.NULL), avroSchema));
-    }
-    return avroSchema;
+    return SchemaUtilities.makeNullable(avroSchema, false);
   }
 
   private static Schema basicSqlTypeToAvroType(BasicSqlType relDataType) {

diff --git a/...chema/src/test/resources/testCaseCallWithNullBranchAndComplexDataTypeBranch-expected.avsc b/...chema/src/test/resources/testCaseCallWithNullBranchAndComplexDataTypeBranch-expected.avsc
@@ -6,7 +6,7 @@
     "name" : "col1",
     "type" : [ "null", {
       "type" : "array",
-      "items" : "string"
+      "items" : [ "null", "string" ]
     } ],
     "doc" : "Field created in view by applying operator 'CASE' with argument(s): true, value with type VARCHAR(65535) ARRAY, value with type VARCHAR(65535) ARRAY"
   } ]

diff --git a/coral-schema/src/test/resources/testProjectUdfReturnedStruct-expected.avsc b/coral-schema/src/test/resources/testProjectUdfReturnedStruct-expected.avsc
@@ -13,10 +13,10 @@
       "namespace" : "default.foo_udf_return_struct.foo_udf_return_struct",
       "fields" : [ {
         "name" : "isEven",
-        "type" : "boolean"
+        "type" : [ "null", "boolean" ]
       }, {
         "name" : "number",
-        "type" : "int"
+        "type" : [ "null", "int" ]
       } ]
     },
     "doc" : "Field created in view by applying UDF 'com.linkedin.coral.hive.hive2rel.CoralTestUDFReturnStruct' with argument(s): coral.schema.avro.base.complex.basecomplex.Id"