fix

Author: kastkeepitjumpinlikekangaroos

pandas/tests/io/test_sql.py

@@ -4374,19 +4374,25 @@ def test_bytes_column(con, request):
 
         dtype = "O"
         val = b"\x01#Eg\x89\xab\xcd\xef\x01#Eg\x89\xab\xcd\xef"
-        if dtype_backend == "pyarrow" and "postgres" in con:
-            # postgres column is a bit type
-            # but converts to a string when returned
-            dtype = pd.ArrowDtype(pa.string())
+
+        if "postgres" in con:
             val = (
-                "0000000100100011010001010110011110001001101010"
+                b"\x00\x00\x00\x80\x01#Eg\x89\xab\xcd\xef\x01#Eg\x89\xab\xcd\xef"
+                if "adbc" in con
+                else "0000000100100011010001010110011110001001101010"
                 "11110011011110111100000001001000110100010101100"
                 "11110001001101010111100110111101111"
             )
-        elif dtype_backend == "pyarrow":
-            # sqlite3 + mysql both return a binary type
-            # for the binary literal
-            dtype = pd.ArrowDtype(pa.binary())
+
+            if "psycopg2" in con and dtype_backend == "numpy_nullable":
+                dtype = pd.StringDtype()
+
+        if dtype_backend == "pyarrow":
+            dtype = (
+                pd.ArrowDtype(pa.string())
+                if "postgres" in con and "adbc" not in con
+                else pd.ArrowDtype(pa.binary())
+            )
 
         expected = DataFrame([{"a": val}], dtype=dtype)
         tm.assert_frame_equal(df, expected)