Fix Postgres array syntax for UPDATE (#644)

Author: raxod502

pypika/queries.py

@@ -1110,7 +1110,9 @@ def minus(self, other: "QueryBuilder") -> _SetOperation:
     @builder
     def set(self, field: Union[Field, str], value: Any) -> None:
         field = Field(field) if not isinstance(field, Field) else field
-        self._updates.append((field, self._wrapper_cls(value)))
+        if not isinstance(value, Term):
+            value = self.wrap_constant(value, wrapper_cls=self._wrapper_cls)
+        self._updates.append((field, value))
 
     def __add__(self, other: "QueryBuilder") -> _SetOperation:
         return self.union(other)

pypika/terms.py

@@ -586,7 +586,7 @@ def get_sql(self, **kwargs: Any) -> str:
 
 class NullValue(LiteralValue):
     def __init__(self, alias: Optional[str] = None) -> None:
-        super().__init__("NULL", alias)
+        super().__init__("null", alias)
 
 
 class SystemTimeValue(LiteralValue):

pypika/tests/dialects/test_postgresql.py

@@ -20,6 +20,15 @@ def test_array_keyword(self):
         self.assertEqual("INSERT INTO \"abc\" VALUES (1,ARRAY[1,'a',true])", str(q))
 
 
+class UpdateTests(unittest.TestCase):
+    table_abc = Table("abc")
+
+    def test_postgresquery(self):
+        q = PostgreSQLQuery.update(self.table_abc).set(1, [1, "a", True])
+
+        self.assertEqual("UPDATE \"abc\" SET \"1\"=ARRAY[1,'a',true]", str(q))
+
+
 class JSONObjectTests(unittest.TestCase):
     def test_alias_set_correctly(self):
         table = Table('jsonb_table')

pypika/tests/test_inserts.py

@@ -149,7 +149,7 @@ def test_insert_ignore(self):
     def test_insert_null(self):
         query = Query.into(self.table_abc).insert(None)
 
-        self.assertEqual('INSERT INTO "abc" VALUES (NULL)', str(query))
+        self.assertEqual('INSERT INTO "abc" VALUES (null)', str(query))
 
     def test_insert_column_using_table_alias(self):
         q = self.table_abc.insert(1)
@@ -541,7 +541,7 @@ def test_insert_all_columns_single_element_arrays(self):
     def test_insert_returning_null(self):
         query = PostgreSQLQuery.into(self.table_abc).insert(1).returning(None)
 
-        self.assertEqual('INSERT INTO "abc" VALUES (1) RETURNING NULL', str(query))
+        self.assertEqual('INSERT INTO "abc" VALUES (1) RETURNING null', str(query))
 
     def test_insert_returning_tuple(self):
         query = PostgreSQLQuery.into(self.table_abc).insert(1).returning((1, 2, 3))

pypika/tests/test_selects.py

@@ -1167,7 +1167,7 @@ def test_table_with_schema_and_alias(self):
     def test_null_value_with_alias(self):
         q = Query.select(NullValue().as_("abcdef"))
 
-        self.assertEqual('SELECT NULL "abcdef"', str(q))
+        self.assertEqual('SELECT null "abcdef"', str(q))
 
 
 class SubqueryTests(unittest.TestCase):