postgres document store

Storing tree-structured data in a database is a very common requirement, typically such as the forum system's relationship. In the traditional relational database, a variety of solutions have been produced. This paper describes several design patterns of using relational database and document type database as storage in order to store tree structure data as requirement. A. Relational database design Pattern

Storing tree-structured data in a database is a very common requirement, typically such as the Forum system's section relationship. In the traditional relational database, a variety of solutions have been created. In this paper, the storage tree structure data is used as the requirement, and several design patterns are described, which use relational database and document database as storage. A. Relational database design Pattern 1 ID

A few days ago, I wrote an article "industry website construction Keyword Layout", in A5 was Top 8 times, stepped 5 times, in Seowhy was recommended 7 times. In general, it is more gratifying. After all, it is a practical experience written in mind. It is true to promote your website, but also to share skills. Today, I will share with you the layout of the construction document of the industry website. When it comes to file storage, a lot of it is no

Java application 1: Obtain the sample value from the sampling function and store it in the txt document. Import java. io. *; public class Data {public static void main (String [] args) {try {BufferedOutputStream out = new BufferedOutputStream (new FileOutputStream ("data.txt ")); stringBuilder sb = new StringBuilder (""); float f; String _ f; float t = 0; String _ t; int flag = 1; System. out. print ("Steps

Tags: Excel stored as a TXT document When there are multiple rows of data in Excel, we also need to store each row of data into a TXT document, do we need to manually Ctrl + c --> Ctrl + V --> Ctrl + S? The answer is no doubt. Wow, I need to process a document that stores more than 60 thousand pieces of data. In order

By default, the files that are referenced by the layers that are added in the map file Mxd in ArcGIS 10 are absolute paths. This means that if you refer to the "D:\data\DEM.shp" file in the map, the path to the file saved in the Map.mxd file is also "D:\data\DEM.shp". If you want to transfer the project file to a different location, even if you copy the entire project folder, a reference error will also occur when you open the Map.mxd file again.By setting the Mxd file as a reference relative pa