Revize a0602bad

Re #8471 - Added comments for CRUD functions

src/impl/db_manager.py

@@ -10 +10 @@
 
     @staticmethod
     def create(sql: str, values: List, usages: Dict[int, bool] = None) -> bool:
+        """
+        Creates an item in database
+
+        :param sql: SQL query for creation (parameter values are replaced by question mark)
+        :param values: list of parameter values
+        :param usages: dictionary of usages IDs which certificate use
+            Dictionary[Integer, Boolean]
+                - Key = ID (CA_ID=1, SSL_ID=2, SIGNATURE_ID=3, AUTHENTICATION_ID=4)
+                - Value = used=True/unused=False
+
+        :return: the result of whether the creation was successful
+        """
+
         conn = None
         try:
             conn = sqlite3.connect(DATABASE_FILE)
@@ -35 +48 @@
 
     @staticmethod
     def read(sql: str, item_id: int = None):
+        """
+        Reads (selecs) an item or items from database
+
+        :param sql: SQL query for selection (parameter values are replaced by question mark)
+        :param item_id: ID of specific item
+
+        :return: list of rows selected from database
+        """
+
         conn = None
         try:
             conn = sqlite3.connect(DATABASE_FILE)
@@ -57 +79 @@
 
     @staticmethod
     def update(sql: str, item_id: int, values: List, usages: Dict[int, bool] = None) -> bool:
+        """
+        Updates an item in database
+
+        :param sql: SQL query for creation (parameter values are replaced by question mark)
+        :param item_id: ID of specific item
+        :param values: list of parameter values
+        :param usages: dictionary of usages IDs which certificate use
+            Dictionary[Integer, Boolean]
+                - Key = ID (CA_ID=1, SSL_ID=2, SIGNATURE_ID=3, AUTHENTICATION_ID=4)
+                - Value = used=True/unused=False
+
+        :return: the result of whether the updation was successful
+        """
+
         conn = None
         try:
             values.append(item_id)
@@ -88 +124 @@
 
     @staticmethod
     def delete(sql: str, item_id: int, delete_usages: bool) -> bool:
+        """
+        Deletes an item from database
+
+        :param sql: SQL query for selection (parameter values are replaced by question mark)
+        :param item_id: ID of specific item
+        :param delete_usages: flag specifying whether to erase rows with specific id
+            from the table of usages (CertificateUsages)
+
+        :return: the result of whether the deletion was successful
+        """
+
         conn = None
         try:
             conn = sqlite3.connect(DATABASE_FILE)