Programmer Think

1, Index principleIndex is an important method to improve the performance of database query.Use indexes to quickly find rows in a column that contain specific values. If you do not use an index, you must start reading from the first record. You may have to read the whole table to find the relevant rows.Using an index is like looking up a dictio ...

Author: Pan Shengwei (Shimian) outline Full link grayscale is one of the core functions of microservices, and it has always been a function that cloud customers must have in the process of microservicing. Full link grayscale involves many technologies and scenarios. If cloud enterprises implement them one by one, they need to spend a lot of m ...

problem When we describe a "good automated test case", the common criteria are: accurate Automated test cases should test one thing, only one thing. An error in a part of an application that is not related to a test case should not cause the test case to fail independent Automated test cases should not be affected by any other tes ...

For Python 2.1 and later versions, unittest is put into the python development package as a standard module. 01 use unittest to write test cases [at the end of the paper, a learning resource for automated testing is prepared for free sharing] Rules: import unittestTo create a test class, you must inherit unittest Testcase classCreate a test ...

1.Map interface    Map And Collection Exist side by side. Used to save files with Mapping relationship Data :key-value  Map Medium key and value Can be data of any reference type  Map Medium key use Set To store, Duplicate is not allowed , i.e. the same Map The class corresponding to the ob ...

Alfred is a powerful artifact that can effectively improve the efficiency of MAC computers. It can be said that with Alfred, you can basically realize various operations without the mouse. Compared with the Mac's own focus search, it can be called a rolling advantage.The following figure shows the Alfred icon on the official website: https://ww ...

1, Character set overviewCharacter Set is a collection of multiple characters. There are many kinds of character sets. Each Character Set contains different numbers of characters. Common Character Set names: ASCII, GB2312, BIG5, Unicode, etc.UTF (Unicode transformation format) is one of the ways to use Unicode, that is, to convert Unicode to a ...

Alfred is a powerful artifact that can effectively improve the efficiency of MAC computers. It can be said that with Alfred, you can basically realize various operations without the mouse. Compared with the Mac's own focus search, it can be called a rolling advantage. The following figure shows the Alfred icon on the official website: https:// ...

Business background There is such a requirement in the project. A form stores supplier information. At the same time, it is necessary to select different suppliers to bring out the basic information and company qualification documents of the corresponding suppliers. Similar to a cascade operation, the supplier information is dynamically displa ...

tinylog( https://tinylog.org/v2/ ), like other things that begin with tiny, is a lightweight open source logging solution. It itself contains only two JAR files (one for API and the other for Implementation), without any external dependencies. The total size of the two JAR files is only 178KB.Although it is a lightweight scheme, the basic log m ...