Go: Ignoring Unused Variables in SQL Statements

When executing SQL statements in Go using the "Exec()" function, multiple values are returned, including a Result object that represents the number of affected rows. However, declaring this Result object unnecessarily can result in compilation errors if the variable is unused.

To address this, the blank identifier (_) can be used to ignore the Result object while still allowing the "Exec()" function to execute. The blank identifier serves as a placeholder for unused values in assignments.

For instance, consider the following code:

stmt, err := db.Prepare("INSERT person SET name=?")
sqlRes, err := stmt.Exec(person.Name)

Here, sqlRes is unused, leading to a compilation error. By replacing sqlRes with _, the code will compile successfully:

stmt, err := db.Prepare("INSERT person SET name=?")
_, err = stmt.Exec(person.Name)

Using the blank identifier allows you to ignore the Result object while maintaining the functionality of the "Exec()" function. This technique can be useful in situations where you only need to execute the SQL statement without capturing the affected rows count.