我需要创建一张新的消费卡

Question

我需要创建一个新的费用卡，输入参数是数量，日期和描述。

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必须在费用卡中填写的字段才能创建它：

持卡人是联系月费用申请是一个自定义对象。

创建费用卡时，如果在“日期”字段中输入的日期前存在月份费用申请，则创建一个新的费用卡，从现有的支出申请中提取月份费用申请。

如果在“日期”字段中输入的日期之前没有月费用申请，则需要创建月费用应用程序，然后创建一个费用地图，其中月份费用应用程序将创建一个新的月费用应用程序。

我试图创建一个与输入参数相等的“金额”“日期”“描述”的费用映射，但我不知道如何指定MonthExpenseApplication__c

public static void createNewExpenseCard(Integer amount, Date createdDate, String description) {
        
        Month_Expense_Application__c MonthApplication = [
            SELECT Name, MonthDate__c
            FROM Month_Expense_Application__c
            WHERE MonthDate__c =: createdDate
        ];
        if (MonthApplication != null) {
            ExpenseCard__c exp = new ExpenseCard__c(
                Amount__c = amount,
                CardDate__c = createdDate,
                Description__c = description,
                CardKeeper__c = '0034x00001K7kGCAAZ'
            );
            exp.MonthExpenseApplication__c = [
                SELECT MonthExpenseApplication__c
                FROM ExpenseCard__c 
                WHERE MonthExpenseApplication__c =: MonthApplication.Id
            ].Id;
            insert exp;
        } else {
            Month_Expense_Application__c monthApp = new Month_Expense_Application__c(
                Balance__c = 1000,
                MonthDate__c = createdDate,
                Keeper__c = '0034x00001K7kGCAAZ'
            );
            ExpenseCard__c exp2 = new ExpenseCard__c(
                Amount__c = amount,
                CardDate__c = createdDate,
                Description__c = description,
                CardKeeper__c = '0034x00001K7kGCAAZ'
            );
            
            insert exp2;
        }
        
    }

Answer 1

这是危险的：

Month_Expense_Application__c MonthApplication = [
            SELECT Name, MonthDate__c
            FROM Month_Expense_Application__c
            WHERE MonthDate__c =: createdDate
        ];

如果结果为零，它将抛出"列表中没有要分配的行。“。如果超过一个的话，也是相似的。

像这样吗？

Integer amount = 50;
Date createdDate = System.today();
String description = 'Lorem ipsum...';

Month_Expense_Application__c app;

List<Month_Expense_Application__c> applications = [SELECT Id
    FROM Month_Expense_Application__c
    WHERE MonthDate__c =: createdDate
    LIMIT 1];

if(applications.isEmpty()){
   app = new Month_Expense_Application__c(
      Balance__c = 1000,
      MonthDate__c = createdDate,
      Keeper__c = '0034x00001K7kGCAAZ'
   );
   insert app;
} else {
   app = applications[0];
}

// one way or another - the monthly allowance exists now. So just use its id in the lookup

ExpenseCard__c exp = new ExpenseCard__c(
   Amount__c = amount,
   CardDate__c = createdDate,
   Description__c = description,
   CardKeeper__c = '0034x00001K7kGCAAZ',
   Month_Expense_Application__c = app.Id
);

有更优雅的方法可以做到这一点，您需要阅读有关upsert和外部ids的内容--但是它应该足够好。