DuckDB uses SUBSTRING instead of SUBSTR

Author: treysp

sqlglot/dialects/duckdb.py

@@ -331,7 +331,7 @@ def _build_capitalization_sql(
 ) -> str:
     # empty string delimiter --> treat value as one word, no need to split
     if raw_delimiters_sql == "''":
-        return f"UPPER(LEFT({value_to_split}, 1)) || LOWER(SUBSTR({value_to_split}, 2))"
+        return f"UPPER(LEFT({value_to_split}, 1)) || LOWER(SUBSTRING({value_to_split}, 2))"
 
     regex_ready_sql = escaped_delimiters_sql or raw_delimiters_sql
     delim_regex_sql = regex_ready_sql
@@ -351,14 +351,14 @@ def _build_capitalization_sql(
             self.func(
                 "LIST_TRANSFORM",
                 self.func("REGEXP_EXTRACT_ALL", value_to_split, split_regex_sql),
-                "(seg, idx) -> CASE WHEN idx % 2 = 0 THEN UPPER(LEFT(seg, 1)) || LOWER(SUBSTR(seg, 2)) ELSE seg END",
+                "(seg, idx) -> CASE WHEN idx % 2 = 0 THEN UPPER(LEFT(seg, 1)) || LOWER(SUBSTRING(seg, 2)) ELSE seg END",
             ),
         )
         .else_(
             self.func(
                 "LIST_TRANSFORM",
                 self.func("REGEXP_EXTRACT_ALL", value_to_split, split_regex_sql),
-                "(seg, idx) -> CASE WHEN idx % 2 = 1 THEN UPPER(LEFT(seg, 1)) || LOWER(SUBSTR(seg, 2)) ELSE seg END",
+                "(seg, idx) -> CASE WHEN idx % 2 = 1 THEN UPPER(LEFT(seg, 1)) || LOWER(SUBSTRING(seg, 2)) ELSE seg END",
             ),
         ),
         "''",

tests/dialects/test_dialect.py

@@ -4373,7 +4373,7 @@ def duckdb_regex_literal_sql(delimiters: str) -> str:
             with self.subTest(f"Testing DuckDB generation for {query} from {dialect}"):
                 self.assertEqual(
                     parse_one(query, read=dialect).sql("duckdb"),
-                    "UPPER(LEFT(col, 1)) || LOWER(SUBSTR(col, 2))",
+                    "UPPER(LEFT(col, 1)) || LOWER(SUBSTRING(col, 2))",
                 )
 
             query = "INITCAP(col, NULL)"