测试结构键和数据是否存在的正确语法是什么？

Question

我在使用 structKeyExists() 测试特定结构键和数据是否存在时遇到问题。

我希望我的查询结果存储在这样的结构中：

APPLICATION.MemQs.ProdCountQs[1].ExpirationDate;
APPLICATION.MemQs.ProdCountQs[1].ProdCount;
APPLICATION.MemQs.ProdCountQs[2].ExpirationDate;
APPLICATION.MemQs.ProdCountQs[2].ProdCount;
APPLICATION.MemQs.ProdCountQs[3].ExpirationDate;
APPLICATION.MemQs.ProdCountQs[3].ProdCount;

// CREATE MEMORY QUERIES ~ works great
if (structKeyExists(APPLICATION, "MemQs") == false) {
    APPLICATION.MemQs = structNew();
}

// CREATE PRODUCT COUNT QUERIES ~ works great
if (structKeyExists(APPLICATION.MemQs, "ProdCountQs") == false) {
    APPLICATION.MemQs.ProdCountQs= structNew();
}

// fails the test ~ always recreates variables
if (structKeyExists(APPLICATION.MemQs, "ProdCountQs[SomeID]") == false) {
    APPLICATION.MemQs.ProdCountQs[SomeID] = structNew();
    APPLICATION.MemQs.ProdCountQs[SomeID].ExpirationDate = now();
    APPLICATION.MemQs.ProdCountQs[SomeID].ProdCount = 0;
}

// fails the test ~ always recreates variables
if (structKeyExists(APPLICATION.MemQs.ProdCountQs, "[SomeID]") == false) {
    APPLICATION.MemQs.ProdCountQs[SomeID] = structNew();
    APPLICATION.MemQs.ProdCountQs[SomeID].ExpirationDate = now();
    APPLICATION.MemQs.ProdCountQs[SomeID].ProdCount = 0;
}

// fails the test ~ always recreates variables
if (structKeyExists(APPLICATION.MemQs.ProdCountQs, "SomeID") == false) {
    APPLICATION.MemQs.ProdCountQs[SomeID] = structNew();
    APPLICATION.MemQs.ProdCountQs[SomeID].ExpirationDate = now();
    APPLICATION.MemQs.ProdCountQs[SomeID].ProdCount = 0;
}

// throws error 
// APPLICATION.MemQs.ProdCountQs[SomeID], must be a syntactically valid variable name
if (isDefined("APPLICATION.MemQs.ProdCountQs[SomeID]") == false) {
    APPLICATION.MemQs.ProdCountQs[SomeID] = structNew();
    APPLICATION.MemQs.ProdCountQs[SomeID].ExpirationDate = now();
    APPLICATION.MemQs.ProdCountQs[SomeID].ProdCount = 0;
}

那么，我该如何使用 structKeyExists() 来测试

是否存在

APPLICATION.MemQs.ProdCountQs[SomeID]

Answer 1

您需要在 SomeID 周围加上井号 ##，因为它是一个变量。

if (structKeyExists(APPLICATION.MemQs.ProdCountQs, "#SomeID#") == false) {
   APPLICATION.MemQs.ProdCountQs[SomeID] = structNew();
   APPLICATION.MemQs.ProdCountQs[SomeID].ExpirationDate = now();
   APPLICATION.MemQs.ProdCountQs[SomeID].ProdCount = 0;
}

如果 SomeID 不是变量，那么在这种情况下，您应该用双引号 "" 将 SomeID 括在方括号中，就像这样 APPLICATION.MemQs.ProdCountQs["SomeID"]。所以代码将如下所示：

if (structKeyExists(APPLICATION.MemQs.ProdCountQs, "SomeID") == false) {
   APPLICATION.MemQs.ProdCountQs["SomeID"] = structNew();
   APPLICATION.MemQs.ProdCountQs["SomeID"].ExpirationDate = now();
   APPLICATION.MemQs.ProdCountQs["SomeID"].ProdCount = 0;
}

编辑
正如 Leigh 所建议的，最好使用 ! 运算符而不是检查 false。此外，如果密钥是一个变量，那么您可以在检查密钥时省略双引号和井号。所以可以这样写if条件：

if (!structKeyExists(APPLICATION.MemQs.ProdCountQs, SomeID))

Answer 2

您似乎正在尝试根据查询创建结构。您应该首先创建结构，然后从您的查询中填充它。在下面的示例中，我假设您有一个查询对象，并且该查询对象中有名为 "ExpirationDate" 和 "ProdCount" 的列。

// create query structure
if(!structKeyExists(APPLICATION, "MemQs")){
    APPLICATION.MemQs = structNew();
    APPLICATION.MemQs.ProdCountQs = arrayNew();
}
// loop through the query
for(row=1;row<=originalQuery.recordcount;row++){
    APPLICATION.MemQs.ProdCountQs[row] = structNew();
    APPLICATION.MemQs.ProdCountQs[row].ExpirationDate = originalQuery.ExpirationDate[row];
    APPLICATION.MemQs.ProdCountQs[row].ProdCount = originalQuery.ProdCount[row];
}

但是，如果您想要检查节点是否存在，您应该像这样逐步遍历树：

// create query structure
if(!structKeyExists(APPLICATION, "MemQs")){
    APPLICATION.MemQs = structNew();
    if(!structKeyExists(APPLICATION.MemQs, "ProdCountQs")){
        APPLICATION.MemQs.ProdCountQs = arrayNew();
        if(!arrayIsDefined(APPLICATION.MemQs.ProdCountQs,someID)){
            APPLICATION.MemQs.ProdCountQs[someID] = structNew();
            if(!structKeyExists(APPLICATION.MemQs.ProdCountQs[someID], "ExpirationDate")){
                APPLICATION.MemQs.ProdCountQs[someID].ExpirationDate = now();
            }
            if(!structKeyExists(APPLICATION.MemQs.ProdCountQs[someID], "ProdCount")){
                APPLICATION.MemQs.ProdCountQs[someID].ProdCount = 0;
            }
        }
    }
}

测试结构键和数据是否存在的正确语法是什么？

What is the correct syntax to test whether a structure key and data exists?

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