Merging upstream version 21.0.1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 14 insertions, 12 deletions

diff --git a/sqlglot/optimizer/simplify.py b/sqlglot/optimizer/simplify.py
index d5b9119..90357dd 100644
--- a/sqlglot/optimizer/simplify.py
+++ b/sqlglot/optimizer/simplify.py
@@ -104,7 +104,6 @@ def simplify(
 
         if root:
             expression.replace(node)
-
         return node
 
     expression = while_changing(expression, _simplify)
@@ -174,16 +173,20 @@ def simplify_not(expression):
         if isinstance(this, exp.Paren):
             condition = this.unnest()
             if isinstance(condition, exp.And):
-                return exp.or_(
-                    exp.not_(condition.left, copy=False),
-                    exp.not_(condition.right, copy=False),
-                    copy=False,
+                return exp.paren(
+                    exp.or_(
+                        exp.not_(condition.left, copy=False),
+                        exp.not_(condition.right, copy=False),
+                        copy=False,
+                    )
                 )
             if isinstance(condition, exp.Or):
-                return exp.and_(
-                    exp.not_(condition.left, copy=False),
-                    exp.not_(condition.right, copy=False),
-                    copy=False,
+                return exp.paren(
+                    exp.and_(
+                        exp.not_(condition.left, copy=False),
+                        exp.not_(condition.right, copy=False),
+                        copy=False,
+                    )
                 )
             if is_null(condition):
                 return exp.null()
@@ -490,7 +493,7 @@ def simplify_equality(expression: exp.Expression) -> exp.Expression:
     if isinstance(expression, COMPARISONS):
         l, r = expression.left, expression.right
 
-        if not l.__class__ in INVERSE_OPS:
+        if l.__class__ not in INVERSE_OPS:
             return expression
 
         if r.is_number:
@@ -714,8 +717,7 @@ def simplify_concat(expression):
     """Reduces all groups that contain string literals by concatenating them."""
     if not isinstance(expression, CONCATS) or (
         # We can't reduce a CONCAT_WS call if we don't statically know the separator
-        isinstance(expression, exp.ConcatWs)
-        and not expression.expressions[0].is_string
+        isinstance(expression, exp.ConcatWs) and not expression.expressions[0].is_string
     ):
         return expression