From 0a75f1cea65eaab96f09fe5bce342597e907e680 Mon Sep 17 00:00:00 2001
From: Tony Locke <tlocke@tlocke.org.uk>
Date: Sat, 17 Aug 2024 14:48:46 +0100
Subject: [PATCH] Simplify identifier() by always quoting.

Previously we only quoted when it had to be.
---
 README.md                |  2 +-
 src/pg8000/converters.py | 23 ++++-------------------
 test/test_converters.py  |  8 ++++----
 3 files changed, 9 insertions(+), 24 deletions(-)

diff --git a/README.md b/README.md
index 05c7fb8..c367e6e 100644
--- a/README.md
+++ b/README.md
@@ -632,7 +632,7 @@ are both separate identifiers. So to escape them you'd do:
 ...     f"WHERE lanname = 'sql'"
 ... )
 >>> print(query)
-SELECT lanname FROM pg_catalog.pg_language WHERE lanname = 'sql'
+SELECT lanname FROM "pg_catalog"."pg_language" WHERE lanname = 'sql'
 >>>
 >>> con.run(query)
 [['sql']]
diff --git a/src/pg8000/converters.py b/src/pg8000/converters.py
index 84593ff..b234236 100644
--- a/src/pg8000/converters.py
+++ b/src/pg8000/converters.py
@@ -772,10 +772,6 @@ def make_params(py_types, values):
     return tuple([make_param(py_types, v) for v in values])
 
 
-def _quote_letter(c):
-    return c.isupper() if c.isalpha() else True
-
-
 def identifier(sql):
     if not isinstance(sql, str):
         raise InterfaceError("identifier must be a str")
@@ -783,22 +779,11 @@ def identifier(sql):
     if len(sql) == 0:
         raise InterfaceError("identifier must be > 0 characters in length")
 
-    quote = _quote_letter(sql[0])
+    if "\u0000" in sql:
+        raise InterfaceError("identifier cannot contain the code zero character")
 
-    for c in sql[1:]:
-        if _quote_letter(c) and c not in "0123456789_$":
-            if c == "\u0000":
-                raise InterfaceError(
-                    "identifier cannot contain the code zero character"
-                )
-            quote = True
-            break
-
-    if quote:
-        sql = sql.replace('"', '""')
-        return f'"{sql}"'
-    else:
-        return sql
+    sql = sql.replace('"', '""')
+    return f'"{sql}"'
 
 
 def literal(value):
diff --git a/test/test_converters.py b/test/test_converters.py
index 4781aec..3504765 100644
--- a/test/test_converters.py
+++ b/test/test_converters.py
@@ -341,14 +341,14 @@ def test_identifier_quoted_null():
 @pytest.mark.parametrize(
     "value,expected",
     [
-        ("top_secret", "top_secret"),
+        ("top_secret", '"top_secret"'),
         (" Table", '" Table"'),
         ("A Table", '"A Table"'),
         ('A " Table', '"A "" Table"'),
-        ("table$", "table$"),
+        ("table$", '"table$"'),
         ("Table$", '"Table$"'),
-        ("tableఐ", "tableఐ"),  # Unicode character 0C10 which is uncased
-        ("table", "table"),
+        ("tableఐ", '"tableఐ"'),  # Unicode character 0C10 which is uncased
+        ("table", '"table"'),
         ("tAble", '"tAble"'),
     ],
 )