Main commit

src/database.rb

@@ -0,0 +1,36 @@
+require 'pg'
+
+class Database
+    def initialize
+        # Connect once when the bot starts
+        @conn = PG.connect(dbname: 'frugality_database')
+
+        init_tables
+    end
+
+    def init_tables
+        sql = <<~SQL
+        CREATE TABLE IF NOT EXISTS total_money (
+            user_id BIGINT PRIMARY KEY,
+            amount BIGINT DEFAULT 0
+        );
+        SQL
+
+        @conn.exec(sql)
+        puts "Database tables have been initialized."
+    end
+
+    # We pass the user_id
+    def get_currency(user_id)
+        # 1. Run the query using parameters ($1) to prevent SQL injection
+        result = @conn.exec_params("SELECT amount FROM total_money WHERE user_id = $1", [user_id])
+
+        # 2. Check if the user exists
+        if result.num_tuples.zero?
+            return 0 # User has no money/row yet
+        else
+        # 3. Return the value (don't print it)
+            return result[0]['amount'].to_i
+        end
+    end
+end