Merge pull request #98 from Knox-AAU/97-database-crud

add database docs

docs/database.md

@@ -0,0 +1,73 @@
+# [Database](https://github.com/Knox-AAU/PreProcessingLayer_EntityRecognitionAndLinking/blob/main/components/Db.py)
+The database is responsible for keeping track of sentences, entity mentions, and entity indices.
+
+## Features
+- CRUD (Create, Read, Update, Delete) Operations supported.
+- Uses [SQLite](https://www.sqlite.org/index.html).
+- Seeds the database with required tables if they do not exist.
+
+## <a name="overview"></a>Overview
+The database contains the following tables:
+
+![](img/database-visualized.png)
+
+### sentence
+Contains each sentence from all input text. Has a unique `sid`.
+
+### entitymention
+Represents each entity mention from all input text. Has `sid` as foreign key (a sentence must exist for the entitymention to exist).
+
+### EntityIndex
+Used by the [Entity Linker](https://github.com/Knox-AAU/PreProcessingLayer_EntityRecognitionAndLinking/blob/main/components/EntityLinker.py) to find potential matches for a given entity mention. See [Entity Linker Docs](https://github.com/Knox-AAU/PreProcessingLayer_EntityRecognitionAndLinking/blob/main/docs/entitylinker.md) for more information. 
+
+## Methods
+```python
+async def InitializeIndexDB(dbPath):
+```
+### Parameters:
+- **dbPath** (str): A path where the database will be stored / is stored, ie. `some/path/to/a/Database/directory`.
+
+```python
+async def Insert(dbPath, tableName, queryInformation):
+```
+### Parameters:
+- **dbPath** (str): A path where the database will be stored / is stored, ie. `some/path/to/a/Database/directory`.
+- **tableName** (str): The name of the table you want to insert into, available ones can be found in [Overview](##Overview).
+- **queryInformation** (JSON): A JSON object containing the key-value pairs you want to insert, for example: 
+```JSON
+{
+    "fileName": "article.txt",
+    "string": "A duck walked across the road",
+    "startindex": 20,
+    "endIndex": 29
+}
+```
+Would be a valid insert in the `sentence` table.
+
+> **_NOTE:_** The `sid` is autogenerated using `AUTOINCREMENT`.
+
+```python
+async def Read(dbPath, tableName, searchPred=""):
+```
+### Parameters:
+- **dbPath** (str): A path where the database will be stored / is stored, ie. `some/path/to/a/Database/directory`.
+- **tableName** (str): The name of the table you want to insert into, available ones can be found in [Overview](##Overview).
+- The search predicate to query the table with, for example if `searchPred` = `Jones` and the `tableName` = `entitymention`, the entitymention table will be searched for `Jones`.
+
+```python
+async def Update(dbPath, tableName, indexID, updatedName):
+```
+### Parameters:
+- **dbPath** (str): A path where the database will be stored / is stored, ie. `some/path/to/a/Database/directory`.
+- **tableName** (str): The name of the table you want to insert into, available ones can be found in [Overview](##Overview).
+- **indexID** (str): The `sid`, `eid` or `id` (EntityIndex) to update.
+- **updatedName** (str): What the `string`, `mention` or `name` should be updated to.
+
+
+```python
+async def Delete(dbPath, tableName, indexID):
+```
+### Parameters:
+- **dbPath** (str): A path where the database will be stored / is stored, ie. `some/path/to/a/Database/directory`.
+- **tableName** (str): The name of the table you want to insert into, available ones can be found in [Overview](##Overview).
+- **indexID** (str): The `sid`, `eid` or `id` (EntityIndex) to delete.