SQL

sql group by example

 SELECT column_name(s)
  FROM table_name
  WHERE condition
  GROUP BY column_name(s)
  HAVING condition
  ORDER BY column_name(s); 

Group By

nums = new int[]{1,1,2,3,4,4,4,4,5};
var groupS =nums.GroupBy(x => x);
// for detail view take look at below or click on source link 
// https://leetcode.com/problems/majority-element/discuss/2657752/103-ms-faster-than-97.70-of-C-online-submissions-One-Liner

group by in sql

GROUP BY: is used to collaborate
with the SELECT statement to arrange 
matching data into groups.

ORDER BY: is for sorting result
either in descending or ascending order.

SQL GROUP BY

SELECT country, COUNT(*) AS number
FROM Customers
GROUP BY country;

group by

SELECT
  <column_name>,
  COUNT(<column_name>) AS `value_occurrence` 

FROM
  <my_table>

GROUP BY 
  <column_name>

ORDER BY 
  `value_occurrence` DESC

LIMIT 1;

group by sql

SELECT NAME, SUM(SALARY) FROM Employee 
GROUP BY NAME;

GROUP BY

SELECT <field1, field2, field3…>
FROM <table1_name>
WHERE <condition/expression>
GROUP BY <field1, field2, field3…>

group by

function groupBy(array, keyFn) {
  return array.reduce((accumulator, value) => {
    const key = keyFn(value);
    if (!accumulator[key]) {
      accumulator[key] = [value];
    } else {
      accumulator[key] = [value];
    }
    return accumulator;
  }, {});
}

group function in sql

--- GROUP FUNCTION | MULTI ROW FUNCTION | AGGREGATE FUNCTION 
--- COUNT , MAX , MIN , SUM , AVG

group functions in sql

Multiple Row Functions (Group functions, Aggregate functions):
(Count, MIN , MAX, AVG, SUM)
will run for multiple rows and return a single value