Return value from 'Future' function - flutter

Question

I hope you can help me with getting a return value out of a future function.
I created a local MariaDB and connect to it with the mysql1 package. The next step is to get a value whenever a table is empty or not (indicates as 0 or 1). I archive that behavior with the following SQL query SELECT EXISTS (SELECT 1 FROM table);
Function to create a db connection.
//creates connection to local database. (used in .this((conn){}) function)
Future<MySqlConnection> getConnection() async {
var settings = ConnectionSettings(
host: host!,
port: port!,
user: user,
password: password,
db: db,
);
return await MySqlConnection.connect(settings);
}
My Function that should return 0 or 1, let me explan the code block down below.
getConnection() create database connection
trigger .then() to work with the output as conn
execute SQL query
format SQL query to just 0 or 1
Missing: should return the value when checkIfTableIsEmpty() is called
//should return 0 or 1 depending if table is empty or not.
checkIfTableIsEmpty(String table) async {
//holds the sql query that should get executed.
String sql = 'SELECT EXISTS (SELECT 1 FROM $table);';
//this should get returned after annitialised.
String? globalNumber;
//!!! creates the value 0 or 1 !!!
await getConnection().then( // (1)
(conn) async { // (2)
//output: result = (Fields: {EXISTS (SELECT 1 FROM master_key): 1})
Results result = await conn.query(sql); //(3)
String? number;
for (var row in result) {. // (4) <---- format output to just 0 or 1
number = '${row[0]}';
}
globalNumber = number;
print('$globalNumber'); // <---- output is 1
return globalNumber;
});
// (5) globalNumber should get printed
print('$globalNumber'); // <---- output null, this should be 1
}
Function that is currently returning null but should get value of globalNumber var.
//call the function and print result.
void testFunction() async {
print(checkIfTableIsEmpty('master_key'));
}

Answer 1

Hello i found the solution for my problem. I had to await on the result and delete the .then() function to avoid having callbacks. (See the comment of #Almis).
Thanks #Almis for the code improvement.
This is my final function that return 0 or 1.
checkIfTableIsEmpty(String table) async {
String sql = 'SELECT EXISTS (SELECT 1 FROM $table);';
String? globalNumber;
var conn = await getConnection();
Results result = await conn.query(sql);
for (var row in result) {
globalNumber = '${row[0]}';
}
return globalNumber;
}
void testFunction() async {
var x = await checkIfTableIsEmpty('master_key');
print(x);
}