Golang SQL: Problems with existing libraries

calling-defer-close-at-the-wrong-time.go

rows, err := db.Query("...")
defer rows.Close()
if err != nil { ... }
for rows.Next() {
	var user User
	err = rows.Scan(...)
	if err != nil { ... }
}
if rows.Err() != nil { ... }

code-duplication-with-big-structs.go

rows, err := db.Query(`SELECT
    id,
    username,
    age,
    -- other attributes --
FROM users
WHERE ...`)
// ...
for rows.Next() {
    var user User
    err = rows.Scan(
        &user.ID,
        &user.Username,
        &user.Age,
        // other attributes
    )
    // ...
}

handling-errors-multiple-times.go

rows, err := db.Query("...")
if err != nil { ... }
defer func() {
	err = rows.Close()
	if err != nil { ... }
}()
for rows.Next() {
	var user User
	err = rows.Scan(...)
	if err != nil { ... }
}
if rows.Err() != nil { ... }

ksql-example.go

type User struct{
    ID   int    `ksql:"user_id"`
    Name string `ksql:"name"`
    Age  string `ksql:"age"`
}
var users []User
err := db.Query(ctx, &users, `FROM users WHERE type = $1`, userType)
if err != nil { ... }