Added the sql storage medium to easily manage storages

src/main/java/de/gnmyt/SQLToolkit/storage/SQLStorageMedium.java

@@ -0,0 +1,88 @@
+package de.gnmyt.SQLToolkit.storage;
+
+import de.gnmyt.SQLToolkit.drivers.MySQLConnection;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+public abstract class SQLStorageMedium extends SQLTable {
+
+    /**
+     * The basic constructor of the {@link SQLStorageMedium}
+     *
+     * @param connection The mysql connection you want to use
+     */
+    public SQLStorageMedium(MySQLConnection connection) {
+        super(connection);
+    }
+
+    @Override
+    protected void tableFields() {
+        string("keyName", 255, "");
+        string("value", 2000, "");
+    }
+
+    /**
+     * Checks if a key exists in the storage medium
+     *
+     * @param key The key you want to check
+     * @return <code>true</code> if the key exists, otherwise <code>false</code>
+     */
+    public boolean exists(String key) {
+        return select().where("keyName", key).getResult().exists();
+    }
+
+    /**
+     * Inserts a key into the storage medium
+     *
+     * @param key   The key you want to insert
+     * @param value The value you want to insert
+     */
+    public void insert(String key, String value) {
+        insert().value("keyName", key).value("value", value).execute();
+    }
+
+    /**
+     * Updates a key in the storage medium
+     *
+     * @param key   The key you want to use
+     * @param value The value you want to update
+     */
+    public void update(String key, String value) {
+        update().where("keyName", key).set("value", value).update();
+    }
+
+    /**
+     * Deletes a key from the storage medium
+     *
+     * @param key The key you want to delete
+     */
+    public void delete(String key) {
+        update().where("keyName", key).delete();
+    }
+
+    /**
+     * Gets all entries from the storage medium
+     *
+     * @return the entries from the storage medium
+     */
+    public ArrayList<HashMap<String, Object>> getEntries() {
+        return select().getResult().getList();
+    }
+
+    /**
+     * Inserts or updates the key of the storage medium.
+     * If the entry is currently in the storage medium, it updates it. Otherwise, it will insert it
+     *
+     * @param key   The key you want to insert / update
+     * @param value The value you want to insert / update
+     */
+    public void insertOrUpdate(String key, String value) {
+        if (exists(key)) {
+            update(key, value);
+        } else {
+            insert(key, value);
+        }
+    }
+
+}