feat(postgres,trino,duckdb): added support for current_catalog

sqlglot/dialects/dialect.py

@@ -296,6 +296,17 @@ def get_start_end(token_type: TokenType) -> t.Tuple[t.Optional[str], t.Optional[
                 no_paren_functions.pop(TokenType.LOCALTIMESTAMP, None)
             klass.parser_class.NO_PAREN_FUNCTIONS = no_paren_functions
 
+        if enum not in (
+            "",
+            "postgres",
+            "duckdb",
+            "presto",
+            "trino",
+        ):
+            no_paren_functions = klass.parser_class.NO_PAREN_FUNCTIONS.copy()
+            no_paren_functions.pop(TokenType.CURRENT_CATALOG, None)
+            klass.parser_class.NO_PAREN_FUNCTIONS = no_paren_functions
+
         klass.VALID_INTERVAL_UNITS = {
             *klass.VALID_INTERVAL_UNITS,
             *klass.DATE_PART_MAPPING.keys(),

sqlglot/dialects/duckdb.py

@@ -976,6 +976,7 @@ class Generator(generator.Generator):
             exp.JSONObjectAgg: rename_func("JSON_GROUP_OBJECT"),
             exp.JSONBObjectAgg: rename_func("JSON_GROUP_OBJECT"),
             exp.DateBin: rename_func("TIME_BUCKET"),
+            exp.CurrentCatalog: lambda *_: "CURRENT_CATALOG",
         }
 
         SUPPORTED_JSON_PATH_PARTS = {

sqlglot/dialects/postgres.py

@@ -729,6 +729,7 @@ class Generator(generator.Generator):
             exp.JSONObjectAgg: rename_func("JSON_OBJECT_AGG"),
             exp.JSONBObjectAgg: rename_func("JSONB_OBJECT_AGG"),
             exp.CountIf: count_if_to_sum,
+            exp.CurrentCatalog: lambda *_: "CURRENT_CATALOG",
         }
 
         TRANSFORMS.pop(exp.CommentColumnConstraint)

sqlglot/dialects/trino.py

@@ -93,6 +93,7 @@ class Generator(Presto.Generator):
             ),
             exp.TimeStrToTime: lambda self, e: timestrtotime_sql(self, e, include_precision=True),
             exp.Trim: trim_sql,
+            exp.CurrentCatalog: lambda *_: "CURRENT_CATALOG",
         }
 
         SUPPORTED_JSON_PATH_PARTS = {

sqlglot/expressions.py

@@ -6356,6 +6356,10 @@ class CurrentUser(Func):
     arg_types = {"this": False}
 
 
+class CurrentCatalog(Func):
+    arg_types = {}
+
+
 class CurrentRegion(Func):
     arg_types = {}
 

sqlglot/parser.py

@@ -289,6 +289,7 @@ class Parser(metaclass=_Parser):
         TokenType.CURRENT_TIME: exp.CurrentTime,
         TokenType.CURRENT_TIMESTAMP: exp.CurrentTimestamp,
         TokenType.CURRENT_USER: exp.CurrentUser,
+        TokenType.CURRENT_CATALOG: exp.CurrentCatalog,
         TokenType.LOCALTIME: exp.Localtime,
         TokenType.LOCALTIMESTAMP: exp.Localtimestamp,
         TokenType.CURRENT_ROLE: exp.CurrentRole,
@@ -638,6 +639,7 @@ class Parser(metaclass=_Parser):
         TokenType.CURRENT_TIMESTAMP,
         TokenType.CURRENT_TIME,
         TokenType.CURRENT_USER,
+        TokenType.CURRENT_CATALOG,
         TokenType.FILTER,
         TokenType.FIRST,
         TokenType.FORMAT,

sqlglot/tokens.py

@@ -277,6 +277,7 @@ class TokenType(AutoName):
     CURRENT_TIMESTAMP = auto()
     CURRENT_USER = auto()
     CURRENT_ROLE = auto()
+    CURRENT_CATALOG = auto()
     DECLARE = auto()
     DEFAULT = auto()
     DELETE = auto()
@@ -758,6 +759,7 @@ class Tokenizer(metaclass=_Tokenizer):
         "CURRENT_TIME": TokenType.CURRENT_TIME,
         "CURRENT_TIMESTAMP": TokenType.CURRENT_TIMESTAMP,
         "CURRENT_USER": TokenType.CURRENT_USER,
+        "CURRENT_CATALOG": TokenType.CURRENT_CATALOG,
         "DATABASE": TokenType.DATABASE,
         "DEFAULT": TokenType.DEFAULT,
         "DELETE": TokenType.DELETE,

tests/dialects/test_dialect.py

@@ -4765,3 +4765,38 @@ def test_localtime_and_localtimestamp(self):
                     select = parse_one(sql, dialect=dialect)
                     select.selects[0].assert_is(exp.Column)
                     self.assertEqual(select.sql(dialect), sql)
+
+    def test_current_catalog(self):
+        sql = "SELECT CURRENT_CATALOG"
+
+        unsupported_dialects = [
+            "bigquery",
+            "mysql",
+            "oracle",
+            "clickhouse",
+            "snowflake",
+            "spark",
+            "databricks",
+        ]
+
+        for dialect in unsupported_dialects:
+            with self.subTest(f"Testing CURRENT_CATALOG as Column in {dialect}"):
+                select = parse_one(sql, dialect=dialect)
+                select.selects[0].assert_is(exp.Column)
+                self.assertEqual(select.sql(dialect), sql)
+
+        supported_dialects = [
+            "postgres",
+            "duckdb",
+            "trino",
+            "databricks",
+        ]
+
+        for dialect in supported_dialects:
+            with self.subTest(f"Testing CURRENT_CATALOG expression in {dialect}"):
+                if dialect == "databricks":
+                    sql = "SELECT CURRENT_CATALOG()"
+                select = parse_one(sql, dialect=dialect)
+                select.selects[0].assert_is(exp.CurrentCatalog)
+
+                self.assertEqual(select.sql(dialect), sql)