feat: add support for show databases

evadb/catalog/catalog_manager.py

@@ -161,6 +161,9 @@ def get_database_catalog_entry(self, database_name: str) -> DatabaseCatalogEntry
 
         return table_entry
 
+    def get_all_database_catalog_entries(self):
+        return self._db_catalog_service.get_all_entries()
+
     def drop_database_catalog_entry(self, database_entry: DatabaseCatalogEntry) -> bool:
         """
         This method deletes the database from  catalog.

evadb/executor/show_info_executor.py

@@ -32,6 +32,7 @@ def exec(self, *args, **kwargs):
         assert (
             self.node.show_type is ShowType.FUNCTIONS
             or ShowType.TABLES
+            or ShowType.DATABASES
             or ShowType.CONFIG
         ), f"Show command does not support type {self.node.show_type}"
 
@@ -45,6 +46,10 @@ def exec(self, *args, **kwargs):
                 if table.table_type != TableType.SYSTEM_STRUCTURED_DATA:
                     show_entries.append(table.name)
             show_entries = {"name": show_entries}
+        elif self.node.show_type is ShowType.DATABASES:
+            databases = self.catalog().get_all_database_catalog_entries()
+            for db in databases:
+                show_entries.append(db.display_format())
         elif self.node.show_type is ShowType.CONFIG:
             value = self._config.get_value(
                 category="default",

evadb/parser/evadb.lark

@@ -177,7 +177,7 @@ describe_statement: DESCRIBE table_name
 
 help_statement: HELP STRING_LITERAL
 
-show_statement: SHOW (FUNCTIONS | TABLES | uid)
+show_statement: SHOW (FUNCTIONS | TABLES | uid | DATABASES)
 
 explain_statement: EXPLAIN explainable_statement
 
@@ -341,6 +341,7 @@ CHUNK_OVERLAP:                       "CHUNK_OVERLAP"i
 COLUMN:                              "COLUMN"i
 CREATE:                              "CREATE"i
 DATABASE:                            "DATABASE"i
+DATABASES:                           "DATABASES"i
 DEFAULT:                             "DEFAULT"i
 DELETE:                              "DELETE"i
 DESC:                                "DESC"i

evadb/parser/lark_visitor/_show_statements.py

@@ -27,5 +27,7 @@ def show_statement(self, tree):
             return ShowStatement(show_type=ShowType.FUNCTIONS)
         elif isinstance(token, str) and str.upper(token) == "TABLES":
             return ShowStatement(show_type=ShowType.TABLES)
+        elif isinstance(token, str) and str.upper(token) == "DATABASES":
+            return ShowStatement(show_type=ShowType.DATABASES)
         elif token is not None:
             return ShowStatement(show_type=ShowType.CONFIG, show_val=self.visit(token))

evadb/parser/show_statement.py

@@ -42,7 +42,8 @@ def __str__(self):
             show_str = "TABLES"
         elif self.show_type == ShowType.CONFIG:
             show_str = self.show_val
-
+        elif self.show_type == ShowType.DATABASES:
+            show_str = "DATABASES"
         return f"SHOW {show_str}"
 
     def __eq__(self, other: object) -> bool:

evadb/parser/types.py

@@ -71,6 +71,7 @@ class ShowType(EvaDBEnum):
     FUNCTIONS  # noqa: F821
     TABLES  # noqa: F821
     CONFIG  # noqa: F821
+    DATABASES  # noqa: F821
 
 
 class FunctionType(EvaDBEnum):

evadb/plan_nodes/show_info_plan.py

@@ -36,6 +36,8 @@ def show_val(self):
     def __str__(self):
         if self._show_type == ShowType.FUNCTIONS:
             return "ShowFunctionPlan"
+        if self._show_type == ShowType.DATABASES:
+            return "ShowDatabasePlan"
         elif self._show_type == ShowType.TABLES:
             return "ShowTablePlan"
         elif self._show_type == ShowType.CONFIG:

test/integration_tests/short/test_show_info_executor.py

@@ -28,7 +28,7 @@
 from evadb.models.storage.batch import Batch
 from evadb.server.command_handler import execute_query_fetch_all
 
-NUM_FRAMES = 10
+NUM_DATABASES = 6
 
 
 @pytest.mark.notparallel
@@ -48,12 +48,39 @@ def setUpClass(cls):
         execute_query_fetch_all(cls.evadb, f"LOAD VIDEO '{mnist}' INTO MNIST;")
         execute_query_fetch_all(cls.evadb, f"LOAD VIDEO '{actions}' INTO Actions;")
 
+        # create databases
+        import os
+
+        cls.current_file_dir = os.path.dirname(os.path.abspath(__file__))
+        for i in range(NUM_DATABASES):
+            database_path = f"{cls.current_file_dir}/testing_{i}.db"
+            params = {
+                "database": database_path,
+            }
+            query = """CREATE DATABASE test_data_source_{}
+                        WITH ENGINE = "sqlite",
+                        PARAMETERS = {};""".format(
+                i, params
+            )
+            execute_query_fetch_all(cls.evadb, query)
+
     @classmethod
     def tearDownClass(cls):
         execute_query_fetch_all(cls.evadb, "DROP TABLE IF EXISTS Actions;")
         execute_query_fetch_all(cls.evadb, "DROP TABLE IF EXISTS MNIST;")
         execute_query_fetch_all(cls.evadb, "DROP TABLE IF EXISTS MyVideo;")
 
+        # remove all the DATABASES
+        for i in range(NUM_DATABASES):
+            execute_query_fetch_all(
+                cls.evadb, f"DROP DATABASE IF EXISTS test_data_source_{i};"
+            )
+            database_path = f"{cls.current_file_dir}/testing_{i}.db"
+            import contextlib
+
+            with contextlib.suppress(FileNotFoundError):
+                os.remove(database_path)
+
     # integration test
     def test_show_functions(self):
         result = execute_query_fetch_all(self.evadb, "SHOW FUNCTIONS;")
@@ -100,3 +127,17 @@ def test_show_config_execution(self):
         # Ensure an Exception is raised if config is not present
         with self.assertRaises(Exception):
             execute_query_fetch_all(self.evadb, "SHOW BADCONFIG")
+
+    # integration test
+    def test_show_databases(self):
+        result = execute_query_fetch_all(self.evadb, "SHOW DATABASES;")
+        self.assertEqual(len(result.columns), 3)
+        self.assertEqual(len(result), 6)
+
+        expected = {
+            "name": [f"test_data_source_{i}" for i in range(NUM_DATABASES)],
+            "engine": ["sqlite" for _ in range(NUM_DATABASES)],
+        }
+        expected_df = pd.DataFrame(expected)
+        self.assertTrue(all(expected_df.name == result.frames.name))
+        self.assertTrue(all(expected_df.engine == result.frames.engine))

test/unit_tests/parser/test_parser_statements.py

@@ -80,6 +80,7 @@ def test_parser_statement_types(self):
             """,
             "SHOW TABLES;",
             "SHOW FUNCTIONS;",
+            "SHOW DATABASES;",
             "EXPLAIN SELECT a FROM foo;",
             "SELECT HomeRentalForecast(12);",
             """SELECT data FROM MyVideo WHERE id < 5