Repository: mindsdb/mindsdb

Issue:
[New Integration]: Integration with crateDB
### Is there an existing integration?

- [X] I have searched the existing integrations.

### Use Case

**CrateDB is more efficient than MongoDB in terms of memory and storage, and it is easier to scale. It offers real-time responses even with high data volumes, high concurrency, and a variety of data types. On top of that, CrateDB is accessible through SQL.
.**
It is used by many organization as cloud database for there App/WebApp/IotApp to provide fast and user-friendly interaction And it as it is **open Source** it is used vastly.

### Motivation

### As it is opensource it is used by many developers and organization and by adding this as integration crateDB users can use mindsdb for there usescases.

### Implementation

_No response_

### Anything else?

_No response_


Discussion:
Please tell if this integration should be added.
If **YES**

### assign it me @ZoranPandovski .

Resolving patch:
diff --git a/mindsdb/integrations/handlers/crate_handler/__about__.py b/mindsdb/integrations/handlers/crate_handler/__about__.py
new file mode 100644
--- /dev/null
+++ b/mindsdb/integrations/handlers/crate_handler/__about__.py
@@ -0,0 +1,9 @@
+__title__ = 'MindsDB Crate DB handler'
+__package_name__ = 'mindsdb_cratedb_handler'
+__version__ = '0.0.1'
+__description__ = "MindsDB handler for Crate DB"
+__author__ = 'Parthiv Makwana'
+__github__ = 'https://github.com/mindsdb/mindsdb'
+__pypi__ = 'https://pypi.org/project/mindsdb/'
+__license__ = 'GPL-3.0'
+__copyright__ = 'Copyright 2022- mindsdb'
diff --git a/mindsdb/integrations/handlers/crate_handler/__init__.py b/mindsdb/integrations/handlers/crate_handler/__init__.py
new file mode 100644
--- /dev/null
+++ b/mindsdb/integrations/handlers/crate_handler/__init__.py
@@ -0,0 +1,20 @@
+from mindsdb.integrations.libs.const import HANDLER_TYPE
+
+try:
+    from .crate_handler import CrateHandler as Handler
+    import_error = None
+except Exception as e:
+    Handler = None
+    import_error = e
+from .__about__ import __version__ as version, __description__ as description
+
+
+title = 'CrateDB'
+name = 'crate'
+type = HANDLER_TYPE.DATA
+icon_path = 'icon.svg'
+
+__all__ = [
+    'Handler', 'version', 'name', 'type', 'title', 'description',
+    'import_error', 'icon_path'
+]
diff --git a/mindsdb/integrations/handlers/crate_handler/crate_handler.py b/mindsdb/integrations/handlers/crate_handler/crate_handler.py
new file mode 100644
--- /dev/null
+++ b/mindsdb/integrations/handlers/crate_handler/crate_handler.py
@@ -0,0 +1,239 @@
+from collections import OrderedDict
+from typing import Optional
+from mindsdb_sql.parser.ast.base import ASTNode
+from mindsdb.integrations.libs.base_handler import DatabaseHandler
+from mindsdb.utilities.log import log
+from mindsdb_sql import parse_sql
+from mindsdb_sql.render.sqlalchemy_render import SqlalchemyRender
+from mindsdb.integrations.libs.response import (
+    HandlerStatusResponse as StatusResponse,
+    HandlerResponse as Response,
+    RESPONSE_TYPE
+)
+from mindsdb.integrations.libs.const import HANDLER_CONNECTION_ARG_TYPE as ARG_TYPE
+
+
+
+import pandas as pd
+from crate import client as db
+from crate.client.sqlalchemy.dialect  import  CrateDialect
+
+
+
+class CrateHandler(DatabaseHandler):
+
+
+    name= 'crate'
+
+    def __init__(self, name: str, connection_data: Optional[dict], **kwargs):
+        """ Initialize the handler
+        Args:
+            name (str): name of particular handler instance
+            connection_data (dict): parameters for connecting to the database
+            **kwargs: arbitrary keyword arguments.
+        """
+        super().__init__(name)
+        
+        self.kwargs = kwargs
+        self.parser = parse_sql
+        self.dialect = 'crate'
+        self.user = connection_data['user']
+        self.password = connection_data['password']
+        self.schemaName = connection_data.get('schema_name','doc')
+        self.host = connection_data['host']
+        self.port = connection_data['port']
+
+        
+        
+
+        self.connection = None
+        self.is_connected = False
+          
+    
+    def connect(self):
+        """ Set up any connections required by the handler
+        Should return output of check_connection() method after attempting
+        connection. Should switch self.is_connected.
+        Returns:
+            Connection Object
+        """
+        if self.is_connected is True:
+            return self.connection
+
+        url="http://{0}:{1}@{2}:{3}".format(self.user,self.password,self.host,self.port)
+        try:
+            self.connection = db.connect(url)
+  
+            self.is_connected= True
+        except Exception as e:
+            log.error(f"Error while connecting to CrateDB, {e}")
+
+
+        return self.connection
+
+
+    def disconnect(self):
+        """ Close any existing connections
+        Should switch self.is_connected.
+        """
+
+        if self.is_connected is False:
+            return
+        try:
+            self.connection.close()
+            self.is_connected=False
+        except Exception as e:
+            log.error(f"Error while disconnecting to CrateDB, {e}")
+
+        return 
+
+
+    def check_connection(self) -> StatusResponse:
+        """ Check connection to the handler
+        Returns:
+            HandlerStatusResponse
+        """
+
+        responseCode = StatusResponse(False)
+        need_to_close = self.is_connected is False
+
+        try:
+            self.connect()
+            responseCode.success = True
+        except Exception as e:
+            log.error(f'Error connecting to  CrateDB, {e}!')
+            responseCode.error_message = str(e)
+        finally:
+            if responseCode.success is True and need_to_close:
+                self.disconnect()
+            if responseCode.success is False and self.is_connected is True:
+                self.is_connected = False
+
+        return responseCode
+
+
+    def native_query(self, query: str) -> StatusResponse:
+        """Receive raw query and act upon it somehow.
+        Args:
+            query (Any): query in native format (str for sql databases,
+                dict for mongo, etc)
+        Returns:
+            HandlerResponse
+        """
+
+        need_to_close = self.is_connected is False
+        
+        conn = self.connect()
+        cur = conn.cursor() 
+        try:
+            cur.execute(query)      
+            if cur.rowcount :
+                result = cur.fetchall() 
+                response = Response(
+                    RESPONSE_TYPE.TABLE,
+                    data_frame=pd.DataFrame(
+                        result,
+                        columns=[x[0] for x in cur.description]
+                    )
+                )
+            else:
+                response = Response(RESPONSE_TYPE.OK)
+        except Exception as e:
+            log.error(f'Error running query: {query} on CrateDB!')
+            response = Response(
+                RESPONSE_TYPE.ERROR,
+                error_message=str(e)
+            )
+        cur.close()
+
+        if need_to_close is True:
+            self.disconnect()
+
+        return response
+
+    
+    def query(self, query: ASTNode) -> StatusResponse:
+        """Receive query as AST (abstract syntax tree) and act upon it somehow.
+        Args:
+            query (ASTNode): sql query represented as AST. May be any kind
+                of query: SELECT, INTSERT, DELETE, etc
+        Returns:
+            HandlerResponse
+        """
+        
+
+
+        renderer = SqlalchemyRender(CrateDialect)
+        query_str = renderer.get_string(query, with_failback=True)
+        return self.native_query(query_str)
+
+
+    def get_tables(self) -> StatusResponse:
+        """ Return list of entities
+        Return list of entities that will be accesible as tables.
+        Returns:
+            HandlerResponse: shoud have same columns as information_schema.tables
+                (https://dev.mysql.com/doc/refman/8.0/en/information-schema-tables-table.html)
+                Column 'TABLE_NAME' is mandatory, other is optional.
+        """
+        
+        q = f"SHOW TABLES FROM {self.schemaName};"
+        result = self.native_query(q)
+        return result
+    
+    def get_columns(self, table_name: str) -> StatusResponse:
+        """ Returns a list of entity columns
+        Args:
+            table_name (str): name of one of tables returned by self.get_tables()
+        Returns:
+            HandlerResponse: shoud have same columns as information_schema.columns
+                (https://dev.mysql.com/doc/refman/8.0/en/information-schema-columns-table.html)
+                Column 'COLUMN_NAME' is mandatory, other is optional. Hightly
+                recomended to define also 'DATA_TYPE': it should be one of
+                python data types (by default it str).
+        """
+
+        
+        q = f"SHOW COLUMNS FROM {table_name};"
+        result = self.native_query(q)
+        return result
+
+
+        
+
+
+
+
+
+connection_args = OrderedDict(
+    host={
+        'type': ARG_TYPE.STR,
+        'description': 'The host name or IP address of the CrateDB server/database.'
+    },
+    user={
+        'type': ARG_TYPE.STR,
+        'description': 'The user name used to authenticate with the CrateDB server.'
+    },
+    password={
+        'type': ARG_TYPE.STR,
+        'description': 'The password to authenticate the user with the CrateDB server.'
+    },
+    port={
+        'type': ARG_TYPE.INT,
+        'description': 'Specify port to connect CrateDB server'
+    }, 
+    schemaName={
+        'type': ARG_TYPE.STR,
+        'description': 'Specify the schema name. Note: It is optional DEFAULT is "doc"'
+    },
+
+)
+
+connection_args_example = OrderedDict(
+    host='127.0.0.1',
+    port='4200',
+    password='',
+    user='crate',
+    
+
+)


Test patch:
diff --git a/mindsdb/integrations/handlers/crate_handler/tests/__init__.py b/mindsdb/integrations/handlers/crate_handler/tests/__init__.py
new file mode 100644
diff --git a/mindsdb/integrations/handlers/crate_handler/tests/test_crate_handler.py b/mindsdb/integrations/handlers/crate_handler/tests/test_crate_handler.py
new file mode 100644
--- /dev/null
+++ b/mindsdb/integrations/handlers/crate_handler/tests/test_crate_handler.py
@@ -0,0 +1,51 @@
+import unittest
+from mindsdb.integrations.handlers.crate_handler.crate_handler import CrateHandler
+from mindsdb.api.mysql.mysql_proxy.libs.constants.response_type import RESPONSE_TYPE
+
+
+class CrateHandlerTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.kwargs = {
+            "host": "127.0.0.1",
+            "port": 4200,
+            "user": "crate",
+            "password": ""
+        }
+        cls.handler = CrateHandler('test_crate_handler', cls.kwargs)
+
+    def test_0_connect(self):
+         self.handler.connect()
+
+    
+
+    def test_1_drop_table(self):
+        res = self.handler.query("DROP TABLE IF EXISTS PREM;")
+        assert res.type is  not RESPONSE_TYPE.ERROR 
+
+
+    def test_2_create_table(self):
+        res = self.handler.query("CREATE TABLE IF NOT EXISTS PREM (Premi varchar(50));")
+        assert res.type is not  RESPONSE_TYPE.ERROR 
+
+    def test_3_insert_table(self):
+        res = self.handler.query("INSERT INTO PREM VALUES('Radha <3 Krishna');")
+        assert res.type is not  RESPONSE_TYPE.ERROR 
+    
+
+    def test_4_get_tables(self):
+        tables = self.handler.get_tables()
+        assert tables.type is not  RESPONSE_TYPE.ERROR
+
+ 
+    def test_5_select_query(self):
+        query = "SELECT * FROM PREM;"
+        result = self.handler.native_query(query)
+        assert result.type is RESPONSE_TYPE.TABLE or RESPONSE_TYPE.OK
+
+    def test_6_check_connection(self):
+         self.handler.check_connection()
+
+        
+if __name__ == '__main__':
+    unittest.main()
\ No newline at end of file