用户不输入时返回默认值

Question

当用户不输入字段 var 时返回默认值（notes ='this will be default'）qapi := `UPDATE custom_param SET param_value = $1, start_date = $2, end_date = $3, status = $4 `enter code here` WHERE param_name = 'default-password'RETURNING param_value, start_date, end_date, status, notes; `// insrt into master_paramsqlError := tx.QueryRowContext(ctx, qapi, request.Value, request.StartDate, request.EndDate, request.Status, request.Notes).Scan(    &value,    &startDate,    &endDate,    &status,    &notes,)queryInsertNotes := `insert `if request.Notes != "" {    notes = request.Notes}if sqlError != nil {    log.Println("SQL Error on ReadApplication on UpdateScheduleMaintenance", sqlError)    tx.Rollback()    return schedule, sqlError}err = tx.Commit()if err != nil {    tx.Rollback()    return schedule, err}当用户不输入任何注释时返回默认注释

Answer 1

我认为你需要这样的东西，没有测试过代码，但你明白了。

notes := "this will be default"

if request.Notes != "" {

    notes = request.Notes

}

qapi := `

UPDATE custom_param SET param_value = $1, start_date = $2, end_date = $3, status = $4, notes = $4 WHERE param_name = 'default-password'

RETURNING param_value, start_date, end_date, status, notes; 

`

// insrt into master_param

sqlError := tx.QueryRowContext(ctx, qapi, request.Value, request.StartDate, request.EndDate, request.Status, notes).Scan(

    &value,

    &startDate,

    &endDate,

    &status,

    &notes,

)

if sqlError != nil {

    log.Println("SQL Error on ReadApplication on UpdateScheduleMaintenance", sqlError)

    tx.Rollback()

    return schedule, sqlError

}

err = tx.Commit()

if err != nil {

    tx.Rollback()

    return schedule, err

}