Go/Golang sql.DB reuse in functions

Question

sql.Open() returns a variable of type *sql.DB

I have a function that calls 10 other functions that all need to make database calls

Is it more correct/efficient t

Answer 1

Declare a var db *sql.DB globally, and then reuse it across your code. Here is an example (simplified):

var db *sql.DB

func DoLotsOfThings() {
    DoTask1(db)
    DoTask2(db)
}

func main() {
  db, _ = sql.Open() # or whatever you use
  defer db.Close()
  DoLotsOfThings()
}

Declaring *sql.DB globally also have some additional benefits such as SetMaxIdleConns (regulating connection pool size) or preparing SQL statements across your application.