Tag:ranking

  • MySQL ranking function implementation

    Time:2021-10-22

    Source of this articleMySQL ranking function implementationReprint, please indicate the source Now there is a need to rank all students’ scores and list their ranking. Just seeing this demand, I was a little confused and had no ideas at all. Why wouldn’t I do it if it was more difficult? Go online to query information, […]

  • Dictionary of Objective-C

    Time:2021-6-29

    introduce Java has map, which can store data in the form of key value pairs. When taking values, you can get the corresponding values directly through the key, which is convenient and fast. In Objective-C language, dictionaries do such things. Like nsarray, a dictionary object can store different types of values. Dictionaries also have immutable […]

  • Set of Objective-C

    Time:2021-6-28

    introduce Java has map, which can store data in the form of key value pairs. When taking values, you can get the corresponding values directly through the key, which is convenient and fast. In Objective-C language, dictionaries do such things. Like nsarray, a dictionary object can store different types of values. Dictionaries also have immutable […]

  • Oracle — window function (2)

    Time:2021-4-20

    Today I’ll talk about how some rank functions use window functions. RANK() OVER ( query_partition_clause ORDER_BY clause) DENSE_RANK( ) OVER ( query_partition_clause ORDER_BY clause ) Example hold scott.emp The table is partitioned according to “deptno”, and then ranked according to “Sal” in the partition. Let’s look at rank first. SQL> conn scott/triger; It’s going to […]

  • 178. Score ranking

    Time:2020-12-10

    Title Description Write a SQL query to achieve score ranking. If the two scores are the same, the two scores rank the same. Note that the next rank after bisection should be the next consecutive integer value. In other words, there should be no “gap” between rankings. +—-+——-+ | Id | Score | +—-+——-+ | […]

  • MySQL 8.0 window function ranking and topn

    Time:2020-11-7

    MySQL 8.0 window function ranking and topn 5.0.5 function has been used in my window before, can be used in a summary of the following functions   what Window function — also known as OLAP function — online analytical processing The window function function is moved from Oracle. It seems that Oracle’s acquisition of MySQL […]

  • Leetcode PHP: d115 506. Relative ranks

    Time:2020-9-6

    D115 506. Relative Ranks Title Link 506. Relative Ranks Topic analysis Given an integral table, gold / silver / bronze medal will be displayed for the first three places, and the rest will be displayed directly. thinking First of all, the index is reserved to sort the integral table, and then the rank is generated […]

  • Programming in C language (12): Eratosthenes sieve method for prime number

    Time:2020-5-25

    Example 12 Eratosthenes sieve method for prime number Problem description The basic idea of Eratosthenes sieve method is to arrange the natural numbers in a certain range from small to large. Declare 1 not prime, remove it; then take the smallest number out of the rest, declare it prime, and remove its multiples. After step […]

  • Oracle rank function (rank) instance details

    Time:2020-4-2

    This article mainly introduces the detailed explanation of the Oracle rank function (rank) instance. Please refer to   –Known: two ranking methods (partitioned and non partitioned): using and not using partition –Two methods of calculation (continuous, discontinuous), corresponding function: deny u rank, rank ·Query original data: student number, name, subject name, score select * from t_score   S_ID […]

  • Oracle Foundation

    Time:2020-4-1

    Oracle am.2019/10/22 C:\app\Administrator\product C:\app\Administrator\oradata C:\app\Administrator\oradata\orcl20. CTL control document20. DBF data file20. Log log file JDK path C:\app\Administrator\product\11.1.0\db_1\jdk\bin Default storage path of database file C:\app\Administrator\product\11.1.0\db_1\database (mysql -u root -p)CMD DOS command line executionSqlplus user name / password sqlplus system/123 Connect to Oracle serverConn username / password as connection identity @ server connection string –Create tablespaceCreate tablespace […]

  • SQL query ranking function instance

    Time:2020-3-18

    In actual development, it is often encountered to calculate the ranking of a field The following table: totak’u sales Now we need to add a sales [rank] field to display the ranking order Method: Copy codeThe code is as follows: SELECT a1.Name, a1.Sales, COUNT(a2.sales) Sales_Rank FROM Total_Sales a1, Total_Sales a2 WHERE a1.Sales <= a2.Sales or […]