Is it better to use `static const std :: string` or just` const std :: string` in a method / function?

Question

I have a method / function:

void foo() {

  static const std::string strSQLQuery = "SELECT ... ";
  // or maybe
  const std::string strSQLQuery = "SELECT ... "; 

  // some operations on strSQLQuery
  // i.e. concatenating with WHERE, etc.:
  const std::string strSQL = strSQLQuery + strWHERE;

  doSthOnDataBase(strSQL);
}

(SQL is just an example)

• static const It will be initialized only once, but it is stored in memory until the process is completed.
• constwill be initialized every time it is executed foo(), but the memory (stack) is freed when the block is completed {}.

On the other hand, the string "SELECT ... "must still be hard-coded in the program code. And that doesn’t matter if we use 1. or 2.

So which approach is better? Using static const std::stringor just const std::string?

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( static const char * const char * qaru.site/questions/364264/..., const char*.)

Answer 1

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Answer 2

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Answer 3

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const int var = 9;
int b = sqrt( var );

int b = sqrt( 9 );

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Answer 4

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:

void call(std::string const& where) {
    static char prefix[] = "SELECT ...";

    std::string strSQL;
    strSQL.reserve(sizeof(prefix)/sizeof(char) + strWHERE.size()); 
    strSQL.append(prefix, sizeof(prefix)/sizeof(char)).append(strWHERE);
    ...
}

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