appmaker不匹配错误，我该如何解决？

Question

我有一个错误，我似乎无法解决它：

Type mismatch: element at [0] should be string, but was: undefined Error: 
Type mismatch: element at [0] should be string, but was: undefined at 
datasources.SitesByld.script:1

Executing query for datasource SitesByld: (Error) : Type mismatch: element 
at [0] should be string, but was: undefined
at datasources.SitesByld.script:1
at Object.success (AppStart:11:14)

Executing query for datasource SitesByld failed.


var record = 
app.models.Sites.getRecord(query.parameters.SitesId);
if (record !== null) {
return [record];
}
return [];

我对编码还很陌生，如果这很简单，请原谅我

Answer 1

在代码末尾，您有一个if子句，但没有else子句？该函数似乎总是返回一个空数组。