• Query SAP multiple database table sizes


    Query SAP multiple database table sizes https://www.cnblogs.com/ken-yu/p/12973009.html Item code db02 Here are two approaches, In the first graphical interface, the results of the query data table are displayed in MB, and only one table can be queried at a time. SPACE—Segments—Detailed Analysis—Detailed Analysis  In the pop-up window segment / object, enter the name of the […]

  • Printf print color


    int main(void) { printf(“\033[31;1m haha\n”); printf(“\033[32;1m haha\n”); printf(“\033[33;1m haha\n”); printf(“\033[34;1m haha\n”); printf(“\033[35;1m haha\n”); printf(“\033[36;1m haha\n”); printf(“\033[37;1m haha\n”); return 0; } result  

  • Regular expressions bring in variables


    Whether the matching string contains a character.For example, it contains the C charactercbde var k =c; var str =”cbde”; var reg =/^c+.*/; var new =reg.test(str) console.log(new) Results: CBDE Now I want to replace c with variable K; Try to use the construction method var kew =’new’ var re =new RegExp(“^key+.*”) var re =new RegExp(“^”+key+”+.*”) console.log(re) […]

  • Mybatis solves the problem of inconsistent entity class attributes and database column names in the development process


    Mybatis solves the problem of inconsistent entity class attributes and database column names in the development process Note: before we stipulated that when writing entity classes, the attribute and database column names must be consistent. Thinking: when the second opening, business changes, etc., the column name in the database is inconsistent with the attribute name […]

  • Node MySQL implements asynchronous operation (Part 2)


    About the previous article node Mysql to achieve asynchronous operation (Part 1) describes how to carry out asynchronous operation, this article mainly introduces how to encapsulate the basic use of node MySQL library Download MySQL Library https://github.com/mysqljs/mysql npm install mysql –save Basic use This is an example from the official GitHub //Connection configuration var mysql […]

  • [pl / SQL] returns the information from the th to the th – paging function


    After reading this chapter, you will learn the following: RowNum & Minus Row_Num_ber,Rank,Densk_rank over(partition by ….. …. ) Generally, in SQL server, we can use sort and limit to get the corresponding range of values, but there are no such functions in PL / SQL. We can use rownum or row_ Number () over (partition […]

  • Configuration of Linux permanent environment variables


    Foreword: in the previous article, I used a command to add angular to the environment variable successfully As shown in the figureUnfortunately, there is a fatal problem with this method. The addition of this environment variable is only temporary. If we exit this shell and open a new shell again, we will report the same […]

  • Using golang’s singleflight to prevent cache breakdown


    background When using cache, it is easy to cause cache breakdown. Cache breakdown: when a key exists, a large number of requests come at the same time, causing all requests to read dB. These requests will break down to the DB, resulting in a large number of transient DB requests and a sudden increase in […]

  • Vue.js Implementation of third party login API in Facebook


    The last article described the implementation of the third party login of line. This article records_ Facebook_ Implementation of Roughly the same, but different! Please poke the demo address here http://download.lllomh.com/cliect/#/product/J417096994417412 1: Developer Platform Configuration Enter developer https://developers.facebook.com/ Create apps (I already have them here) ​ Dynamic operation demonstration: ​ Here we only need the […]

  • Mybatis avoid stream query


    preface When the specified query data is too large, we generally use paging query, page by page to put the data into memory processing. However, in some cases, it is not necessary to query data by paging. If all the data is loaded into memory at once, oom may occur. At this point, we can […]

  • JS multidimensional array flattening


    //Use case: [1, 2, [3, 4, [5, 6, [7, 8]]] //Results: [1 “,” 2 “,” 3 “,” 4 “,” 5 “,” 6 “,” 7 “,” 8 “] const arr = [1, 2, [3, 4, [5, 6, [7, 8]]]] //Method 1 arr.join(‘,’).split(‘,’) //Method 2 arr.toString().split(‘,’)

  • Mongodb document cursor


    Query result traversal When we assign the query result to a JS variable, the query result is actually a cursor You can access the query result item by subscript It can be iterated and traversed Print out all Item1 > var cursor=db.accounts.find({name:’alice2′}); > while(cursor.hasNext()){ print(cursor.next()) } [object BSON] [object BSON] [object BSON] [object BSON] Print […]