转到-在查询周围使用if语句时出错[重复]

Question

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• Undefined err variable 1 answer

I am trying to run this - which would work fine in PHP but in Go I am getting an error:

if strings.EqualFold(update_status, "live") {
    stmt, err := dbmap.Prepare(
        "UPDATE Apps SET version=?,deploy_status=?,status=?,live_date=? WHERE id=?")
} else {
    stmt, err := dbmap.Prepare(
        "UPDATE Apps SET version=?,deploy_status=?,status=? WHERE id=?")
}

I get the error of controllers/apps.go:1095: undefined: stmt in stmt.Exec.

How can I change this so it will work?

Thanks

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Answer 1

Your problem is that you are using Short Variable Declaration, so your stmt and err variables are scoped to the inner block of your conditions (both the if and the else.

This should do the trick:

var stmt *sql.Stmt
var err error
if strings.EqualFold(update_status, "live") {
    stmt, err = dbmap.Prepare(
        "UPDATE Apps SET version=?,deploy_status=?,status=?,live_date=? WHERE id=?")
} else {
    stmt, err = dbmap.Prepare(
        "UPDATE Apps SET version=?,deploy_status=?,status=? WHERE id=?")
}
//stmt is still defined here