Added create DB function in Cache class

cache_manager/_cache.py

@@ -1,18 +1,26 @@
-import sqlite3
 import os
+import sqlite3
+
+__all__ = [
+    'Cache',
+]
 
 
 class Cache:
+    """
+    The Cache class.
+    """
 
     def __init__(self, path: str):
+        """
+        This is not empty.
+        """
 
         self._set_path(path)
 
-
     def __del__(self):
-
-        self.con.close()
 
+        self.con.close()
 
     def _set_path(self, path: str):
 
@@ -26,3 +34,32 @@ def _open_sqlite(self):
 
         self.con = sqlite3.connect(self.path)
         self.cur = self.con.cursor()
+
+    def _create_schema(self):
+
+        self._open_sqlite()
+        self.cur.execute('''
+            CREATE TABLE IF NOT EXISTS
+            main (
+                id INT PRIMARY KEY,
+                item_id VARCHAR,
+                version_id VARCHAR,
+                version INT,
+                status INT,
+                file_name VARCHAR,
+                label VARCHAR,
+                date DATE,
+                extension VARCHAR
+            )
+        ''')
+
+        for typ in ['varchar, int, date']:
+            self.cur.execute(
+                '''
+                CREATE TABLE IF NOT EXISTS
+                attr_{} (
+                    version_id VARCHAR FOREIGN KEY,
+                    value {}
+                )
+            '''.format(typ, typ.upper()),
+            )