Shulou(Shulou.com)06/01 Report--

The content of this article mainly focuses on the use requirements and actual operation of big data asynchronous drop-down tree. The content of the article is clear and clear. It is very suitable for beginners to learn and is worth reading. Interested friends can follow the editor to read together. I hope you can get something through this article!

Question:

The slow loading of the drop-down tree will occur in the parameter template when the amount of data is large. To moisten 5.0, the asynchronous drop-down tree editing style is optimized for this situation.

Optimization principle:

Using an asynchronous drop-down tree, only the data of the first-level node is loaded initially, and when a child node is expanded, its child node data is loaded, and if it is not displayed, it is not loaded.

Special note: the asynchronous drop-down tree provided by the product has strict requirements on the structure of the data table, so that the data set established by any data table can not be used directly.

Details:

Taking the order table in the dry report as an example, if you use the drop-down tree editing style, you only need to specify the value of each layer node and the filter expression except the first layer.

However, if you want to use an asynchronous drop-down tree, you need to meet the following table structure: select real value field, display value field from...

However, in the order table, the regional city is a separate field that does not conform to the above table structure. If you want to use asynchronous drop-down tree optimization, you need to organize the regional city into a field, each value corresponds to a unique code, and then add a father field, the corresponding value of the region in the fathet field is empty, the corresponding value of the city is the number of the region.

The final structure of the data table is as follows:

To satisfy this table structure, you can choose to create a new data table directly, or through other tools, such as a dry aggregator.

After meeting the above requirements, the asynchronous drop-down tree section of the report parameter template is as follows:

Note:

1. First-layer node SQL select ID,NAME from YBXLS where FATHER is null order by ID-find out the first-layer node value by an empty father value

two。 The sublayer node SQL select ID,NAME from YBXLS where FATHER ='$1'order by ID-$1 symbol represents the upper node value

For other settings about the parameter template, please refer to the initial tutorial that comes with moisturizing.

Special note: the cells of the asynchronous drop-down tree cannot use the auto-wrap attribute, otherwise it will cause the drop-down property to be unavailable.

Thank you for your reading. I believe you have a certain understanding of "what are the requirements and actual operation of the asynchronous drop-down tree in big data?" quickly go to practice, if you want to know more related knowledge points, you can pay attention to the website! The editor will continue to bring you better articles!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.