adds the remove function'

src/db.c

@@ -138,8 +138,33 @@ void add_to_db(book_t* book, sqlite3* db)
 	}
 
 	sqlite3_close(db);
+	free(cmd);
+}
+#undef INSERT_STR
 
+#define DEL_STR "DELETE FROM books WHERE id = "
+void remove_from_db(int id, sqlite3* db)
+{
+	int err;
+	char *cmd, *err_msg;
+
+	open_db(&db);
+
+	cmd = malloc(sizeof(char) * (strlen(DEL_STR) + 1));
+	snprintf(cmd, strlen(DEL_STR), "%s", DEL_STR);
+
+	add_int_entry(&cmd, id, true);
+
+	err = sqlite3_exec(db, cmd, 0, 0, &err_msg);
+	if (err != SQLITE_OK) {
+		fprintf(stderr, "sqlite3_exec: %s\n", err_msg);
+		sqlite3_free(err_msg);
+		sqlite3_close(db);
+		exit(EXIT_FAILURE);
+	}
+
+	sqlite3_close(db);
 	free(cmd);
 }
 
-#undef INSERT_STR
+#undef DEL_STR

src/include/db.h

@@ -16,4 +16,7 @@ void setup_db(sqlite3* db);
 
 void add_to_db(book_t* book, sqlite3* db);
 
+void remove_from_db(int id, sqlite3* db);
+
+
 #endif