UI上有4个不同的用户输入字段,如Multiselect Dropdown。用户可以提供输入字段的不同组合以缩小结果集。 (从多选选项中选择所有/几个选项)。
示例:2个多选选项
多选选项A具有元素{“10xyz1”,“11xyz1”,...},
多选选项B包含元素{“xyz101”,“abc111”,...}
2 ^ 2个可能的输入组合(提示:二进制真值表):
1)从多选选项A中选择所有元素&&从多选选项B中选择所有元素,
2)从Multiselect选项A中选择所有元素&&从Multiselect选项B中选择几个元素,
3)从Multiselect选项A中选择几个元素&&从Multiselect选项B中选择所有元素,
4)从Multiselect选项A中选择几个元素&&从Multiselect选项B中选择几个元素
注意:必须从任一选项中选择至少一个元素
我使用了if else语句来实现我的逻辑(我为每个可能的选择分别设置了mongo集合,4个字段,16种可能的组合,所以16个mongo集合),但问题是代码看起来非常难看,有很多if-否则,如果在UI中添加了一个字段,那么我必须检查添加其他条件语句。
现在,条件if-else语句的数量是2 ^ N(其中N是Multiselect下拉输入字段的数量)。
代码片段:
private void constructQuery(MongoQuEry query, AnalysisFilter filter) { query.addFilterField("_id.operator", MongoQuEry.OP_EQUALS, "alpha"); query.addFilterField("_id.month_year", MongoQuEry.OP_IN, getListOfMonthYear(filter)); String collectionName; if (filter.getAllMarket() && filter.getAllCmts() && filter.getAllNode() && filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR.toString(); } else if (filter.getAllMarket() && filter.getAllCmts() && filter.getAllNode()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_PACKAGE.toString(); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } else if (filter.getAllMarket() && filter.getAllCmts() && filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_NODE.toString(); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); } else if (filter.getAllMarket() && filter.getAllCmts()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_NODE_PACKAGE.toString(); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } else if (filter.getAllMarket() && filter.getAllNode() && filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_CMTS.toString(); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); } else if (filter.getAllMarket() && filter.getAllNode()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_CMTS_PACKAGE.toString(); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } else if (filter.getAllMarket() && filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_CMTS_NODE.toString(); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); } else if (filter.getAllMarket()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_CMTS_NODE_PACKAGE.toString(); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } else if (filter.getAllCmts() && filter.getAllNode() && filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); } else if (filter.getAllCmts() && filter.getAllNode()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET_PACKAGE.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } else if (filter.getAllCmts() && filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET_NODE.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); } else if (filter.getAllCmts()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET_NODE_PACKAGE.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } else if (filter.getAllNode() && filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET_CMTS.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); } else if (filter.getAllNode()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET_CMTS_PACKAGE.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } else if (filter.getAllPackage()) { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET_CMTS_NODE.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); } else { collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_MARKET_CMTS_NODE_PACKAGE.toString(); query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket()); query.addFilterField("_id.cmts", MongoQuEry.OP_IN, filter.getCmts()); query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode()); query.addFilterField("_id.package", MongoQuEry.OP_IN, filter.getSubscriberPackage()); } query.setCollection(collectionName); query.addGroupByFields("_id.operator", "_id.month_year"); query.addAliasAggregateField("count", MongoQuEry.AGGR_SUM, "subscriber_count"); int order = MongoQuEry.ORDER_ASC; query.addOrderByFields(order, "_id.month_year"); }
您的集合名称似乎具有基于过滤器字段的模式,如果是这种情况可能有效。
Object marketFilter = filter.getAllMarket();
Object cmtsFilter = filter.getAllCmts();
Object packageFilter = filter.getAllPackage();
Object nodeFilter = filter.getAllNodes();
if(marketFilter != null){
query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket());
}
.
.
. upto filter N
String collectionName = getCollectionName(marketFilter, ... filter N)
/*
create a function getCollectionName(filter1, ... filterN)
in this function you can generate collection name by checking which
filters are not null.
*/
注意: - 仅当您的集合名称基于过滤器时,此方法才有效。
你可以通过对常见条件进行分组来创建决策树,例如,如果每次A都为真,你想执行method1(),而不是在每个'if'上写这个行代码,其中A为真,你可以首先检查A是否为真,然后执行这个公共代码块,然后检查其他条件,如:
而不是写作:
if(a && b) {
example.method1();
example.method2();
// more code 1
} else if(a && !b) {
example.method1();
// more code 2
} else if(!a && b) {
example.method2();
// more code 3
} else if(!a && !b) {
// more code 4
}
你可以写:
if(a) {
example.method1();
if(b) {
example.method2();
// more code 1
} else {
// more code 2
}
} else {
if(b) {
example.method2();
// more code 3
} else {
// more code 4
}
}
怎么样switch case
或IIf
表达?
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/switch
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/conditional-operator
switch case
会更清晰,并将if-else
内容分成几个函数:
void FunctionName()
{
collectionName = CollectionNames.ME_USAGE_MONTH_YEAR_NODE_PACKAGE.toString();
query.addFilterField("_id.node", MongoQuEry.OP_IN, filter.getNode());
query.addFilterField("_id.package", MongoQuEry.OP_IN,
filter.getSubscriberPackage());
}