String Helper functions in EvaDB (#1322)

Added some string helper functions that were missing based on student
feedback. This PR adds support for UPPER, LOWER and CONCAT.

Queries of the form are now supported:

`SELECT CONCAT(UPPER(col1), LOWER(col2), "SOME_SUFFIX") FROM TABLE1`

evadb/functions/function_bootstrap_queries.py

@@ -214,6 +214,30 @@
     EvaDB_INSTALLATION_DIR
 )
 
+Upper_function_query = """CREATE FUNCTION IF NOT EXISTS UPPER
+        INPUT  (input ANYTYPE)
+        OUTPUT (output NDARRAY STR(ANYDIM))
+        IMPL '{}/functions/helpers/upper.py';
+        """.format(
+    EvaDB_INSTALLATION_DIR
+)
+
+Lower_function_query = """CREATE FUNCTION IF NOT EXISTS LOWER
+        INPUT  (input ANYTYPE)
+        OUTPUT (output NDARRAY STR(ANYDIM))
+        IMPL '{}/functions/helpers/lower.py';
+        """.format(
+    EvaDB_INSTALLATION_DIR
+)
+
+Concat_function_query = """CREATE FUNCTION IF NOT EXISTS CONCAT
+        INPUT  (input ANYTYPE)
+        OUTPUT (output NDARRAY STR(ANYDIM))
+        IMPL '{}/functions/helpers/concat.py';
+        """.format(
+    EvaDB_INSTALLATION_DIR
+)
+
 
 def init_builtin_functions(db: EvaDBDatabase, mode: str = "debug") -> None:
     """Load the built-in functions into the system during system bootstrapping.
@@ -261,6 +285,9 @@ def init_builtin_functions(db: EvaDBDatabase, mode: str = "debug") -> None:
         Yolo_function_query,
         stablediffusion_function_query,
         dalle_function_query,
+        Upper_function_query,
+        Lower_function_query,
+        Concat_function_query,
     ]
 
     # if mode is 'debug', add debug functions

evadb/functions/helpers/concat.py

@@ -0,0 +1,38 @@
+# coding=utf-8
+# Copyright 2018-2023 EvaDB
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import pandas as pd
+
+from evadb.functions.abstract.abstract_function import AbstractFunction
+
+
+class Concat(AbstractFunction):
+    def setup(self):
+        pass
+
+    @property
+    def name(self):
+        return "CONCAT"
+
+    def forward(self, df: pd.DataFrame) -> pd.DataFrame:
+        """
+        Concats all the df values into one.
+
+        Returns:
+            ret (pd.DataFrame): Concatenated string.
+        """
+
+        ret = pd.DataFrame()
+        ret["output"] = pd.Series(df.fillna("").values.tolist()).str.join("")
+        return ret

evadb/functions/helpers/lower.py

@@ -0,0 +1,38 @@
+# coding=utf-8
+# Copyright 2018-2023 EvaDB
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import pandas as pd
+
+from evadb.functions.abstract.abstract_function import AbstractFunction
+
+
+class Lower(AbstractFunction):
+    def setup(self):
+        pass
+
+    @property
+    def name(self):
+        return "LOWER"
+
+    def forward(self, df: pd.DataFrame) -> pd.DataFrame:
+        """
+        Converts the string to Lower Case.
+
+        Returns:
+            ret (pd.DataFrame): String converted to Lower Case.
+        """
+
+        ret = pd.DataFrame()
+        ret["output"] = df.map(lambda s: s.lower() if type(s) is str else s)
+        return ret

evadb/functions/helpers/upper.py

@@ -0,0 +1,38 @@
+# coding=utf-8
+# Copyright 2018-2023 EvaDB
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import pandas as pd
+
+from evadb.functions.abstract.abstract_function import AbstractFunction
+
+
+class Upper(AbstractFunction):
+    def setup(self):
+        pass
+
+    @property
+    def name(self):
+        return "UPPER"
+
+    def forward(self, df: pd.DataFrame) -> pd.DataFrame:
+        """
+        Converts the string to Uppercase.
+
+        Returns:
+            ret (pd.DataFrame): String converted to Upper Case.
+        """
+
+        ret = pd.DataFrame()
+        ret["output"] = df.map(lambda s: s.upper() if type(s) is str else s)
+        return ret

test/integration_tests/long/functions/helpers/test_str_helper_functions.py

@@ -0,0 +1,108 @@
+# coding=utf-8
+# Copyright 2018-2023 EvaDB
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+from test.util import get_evadb_for_testing
+
+from evadb.server.command_handler import execute_query_fetch_all
+
+
+class StrHelperTest(unittest.TestCase):
+    def setUp(self) -> None:
+        self.evadb = get_evadb_for_testing()
+        self.evadb.catalog().reset()
+        create_table_query = """CREATE TABLE IF NOT EXISTS Test (
+             input TEXT);
+                """
+        execute_query_fetch_all(self.evadb, create_table_query)
+
+        test_prompts = ["EvaDB"]
+
+        for prompt in test_prompts:
+            insert_query = f"""INSERT INTO Test (input) VALUES ('{prompt}')"""
+            execute_query_fetch_all(self.evadb, insert_query)
+
+    def tearDown(self) -> None:
+        execute_query_fetch_all(self.evadb, "DROP TABLE IF EXISTS Test;")
+
+    def test_upper_function(self):
+        function_name = "UPPER"
+        execute_query_fetch_all(self.evadb, f"DROP FUNCTION IF EXISTS {function_name};")
+        create_function_query = f"""CREATE FUNCTION IF NOT EXISTS {function_name}
+        INPUT  (inp ANYTYPE)
+        OUTPUT (output NDARRAY STR(ANYDIM))
+        TYPE HelperFunction
+        IMPL 'evadb/functions/helpers/upper.py';
+        """
+        execute_query_fetch_all(self.evadb, create_function_query)
+        query = "SELECT UPPER(input) FROM Test;"
+        output_batch = execute_query_fetch_all(self.evadb, query)
+        self.assertEqual(len(output_batch), 1)
+        self.assertEqual(output_batch.frames["upper.output"][0], "EVADB")
+
+        query = "SELECT UPPER('test5')"
+        output_batch = execute_query_fetch_all(self.evadb, query)
+        self.assertEqual(len(output_batch), 1)
+        self.assertEqual(output_batch.frames["upper.output"][0], "TEST5")
+
+    def test_lower_function(self):
+        function_name = "LOWER"
+        execute_query_fetch_all(self.evadb, f"DROP FUNCTION IF EXISTS {function_name};")
+        create_function_query = f"""CREATE FUNCTION IF NOT EXISTS {function_name}
+        INPUT  (inp ANYTYPE)
+        OUTPUT (output NDARRAY STR(ANYDIM))
+        TYPE HelperFunction
+        IMPL 'evadb/functions/helpers/lower.py';
+        """
+        execute_query_fetch_all(self.evadb, create_function_query)
+        query = "SELECT LOWER(input) FROM Test;"
+        output_batch = execute_query_fetch_all(self.evadb, query)
+        self.assertEqual(len(output_batch), 1)
+        self.assertEqual(output_batch.frames["lower.output"][0], "evadb")
+
+        query = "SELECT LOWER('TEST5')"
+        output_batch = execute_query_fetch_all(self.evadb, query)
+        self.assertEqual(len(output_batch), 1)
+        self.assertEqual(output_batch.frames["lower.output"][0], "test5")
+
+    def test_concat_function(self):
+        function_name = "CONCAT"
+        execute_query_fetch_all(self.evadb, f"DROP FUNCTION IF EXISTS {function_name};")
+        create_function_query = f"""CREATE FUNCTION IF NOT EXISTS {function_name}
+        INPUT  (inp ANYTYPE)
+        OUTPUT (output NDARRAY STR(ANYDIM))
+        TYPE HelperFunction
+        IMPL 'evadb/functions/helpers/concat.py';
+        """
+        execute_query_fetch_all(self.evadb, create_function_query)
+
+        execute_query_fetch_all(self.evadb, "DROP FUNCTION IF EXISTS UPPER;")
+        create_function_query = """CREATE FUNCTION IF NOT EXISTS UPPER
+        INPUT  (inp ANYTYPE)
+        OUTPUT (output NDARRAY STR(ANYDIM))
+        TYPE HelperFunction
+        IMPL 'evadb/functions/helpers/upper.py';
+        """
+
+        execute_query_fetch_all(self.evadb, create_function_query)
+        query = "SELECT CONCAT(UPPER('Eva'), 'DB');"
+        output_batch = execute_query_fetch_all(self.evadb, query)
+        self.assertEqual(len(output_batch), 1)
+        self.assertEqual(output_batch.frames["concat.output"][0], "EVADB")
+
+        query = "SELECT CONCAT(input, '.com') FROM Test;"
+        output_batch = execute_query_fetch_all(self.evadb, query)
+        self.assertEqual(len(output_batch), 1)
+        self.assertEqual(output_batch.frames["concat.output"][0], "EvaDB.com")