Should I use StringBuilder or not? [duplicate]

This question already has an answer here:

• StringBuilder vs String concatenation in toString() in Java 11 answers

I have below code in my application at many places. I am using it to prepare SQL queries.

Approach 1:

private String sampleMethod(String name) {
    //null check
    StringBuilder sb = new StringBuilder("Welcome ");
    sb.append(name);
    sb.append(", Have a good day!");
    //System.out.println(sb.toString());
    return sb.toString();
}

Approach 2:

private String sampleMethod(String name) {
    //null check
    //System.out.println("Welcome " + name + ", Have a good day!");
    return "Welcome " + name + ", Have a good day!";
}

1. Which approach should I use?


2. Does both have same memory usage?

Thank you.