Coldfusion 测试结构键和数据是否存在的正确语法是什么？

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如下结构中：

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;
}

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

那么，如何使用structKeyExists（）测试

APPLICATION.MemQs.ProdCountQs[SomeID]

---

你需要在SomeID周围加上pound

#

符号，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

不是一个变量，那么在这种情况下，您应该将

SomeID

用双引号括在方括号中

“

，如下

APPLICATION.MemQs.ProdCountQs[“SomeID”]

。因此，代码将如下所示：

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;
}

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，如果键是一个变量，则在检查键时可以省略双引号和磅符号。因此，您可以编写
if
条件，如下所示：

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

看起来您正在尝试从查询创建结构。您应该首先创建结构，然后从查询中填充它。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

你需要在SomeID周围加上pound##符号，因为它是一个变量。值得注意的是，这只是因为变量名用引号括起来，所以它被视为文本字符串而不是变量名。省略引号，CF将把
SomeID
视为变量。此外，虽然使用“==false”有效，但如果（！structKeyExists（APPLICATION.MemQs.ProdCountQs，SomeID））{…}使用“！”ie
会更短一些，我在变量周围加了磅号，效果非常好。谢谢structKeyExists（APPLICATION.MemQs.ProdCountQs，#SomeID##“==false）@Leigh。正确的。我正在修改代码以反映它。Pankaj-酷。这将有助于下次出现“引用或不引用问题”；-）Evik-是的，虽然这样做有效，但我会去掉引号和#符号。
SomeID
是一个变量（IMO:）这一点打字更少，也更清楚。此外，正确的方法是删除引号，而不是添加磅符号。由于引号是字符串的简写，在删除引号时，实际上是要求CF对照变量的值检查键。