Agrupaments. GROUP BY - Historial de revisió

Joan: /* Having vs WHERE. No és el mateix */

2022-01-31T20:04:11Z

Having vs WHERE. No és el mateix

Joan: /* Having */

2022-01-31T19:52:10Z

Having

Joan: /* SQL GROUP BY and DISTINCT */

2022-01-31T18:24:26Z

SQL GROUP BY and DISTINCT

Joan: Es crea la pàgina amb «=Referència= *https://www.sqltutorial.org/sql-group-by/ =Teoria=

 SELECT    column1,    column2,    AGGREGATE_FUNCTION (column3) FROM    table1 GROUP BY    colum...».

2022-01-31T18:24:09Z

Es crea la pàgina amb «=Referència= *https://www.sqltutorial.org/sql-group-by/ =Teoria= <pre> SELECT column1, column2, AGGREGATE_FUNCTION (column3) FROM table1 GROUP BY colum...».

Pàgina nova

=Referència=
*https://www.sqltutorial.org/sql-group-by/
=Teoria=
<pre>
SELECT
column1,
column2,
AGGREGATE_FUNCTION (column3)
FROM
table1
GROUP BY
column1,
column2;
</pre>

<pre>
SELECT
department_id,
COUNT(employee_id) headcount
FROM employees
GROUP BY department_id;
</pre>
===SQL GROUP BY with INNER JOIN example===
<pre>
SELECT
e.department_id,
department_name,
COUNT(employee_id) headcount
FROM
employees e
INNER JOIN departments d ON d.department_id = e.department_id
GROUP BY
e.department_id;
</pre>
===SQL GROUP BY with ORDER BY example===
<pre>
SELECT
e.department_id,
department_name,
COUNT(employee_id) headcount
FROM
employees e
INNER JOIN
departments d ON d.department_id = e.department_id
GROUP BY e.department_id
ORDER BY headcount DESC;
</pre>
===SQL GROUP BY with HAVING example===
<pre>
SELECT
e.department_id,
department_name,
COUNT(employee_id) headcount
FROM
employees e
INNER JOIN
departments d ON d.department_id = e.department_id
GROUP BY e.department_id
HAVING headcount > 5
ORDER BY headcount DESC;
</pre>
===SQL GROUP BY with MIN, MAX, and AVG example===
<pre>
SELECT
e.department_id,
department_name,
MIN(salary) min_salary,
MAX(salary) max_salary,
ROUND(AVG(salary), 2) average_salary
FROM
employees e
INNER JOIN
departments d ON d.department_id = e.department_id
GROUP BY e.department_id;
</pre>

===SQL GROUP BY with SUM function example===
<pre>
SELECT
e.department_id,
department_name,
SUM(salary) total_salary
FROM
employees e
INNER JOIN
departments d ON d.department_id = e.department_id
GROUP BY e.department_id;
</pre>
===SQL GROUP BY multiple columns===
<pre>
SELECT
e.department_id,
department_name,
e.job_id,
job_title,
COUNT(employee_id)
FROM
employees e
INNER JOIN
departments d ON d.department_id = e.department_id
INNER JOIN
jobs j ON j.job_id = e.job_id
GROUP BY e.department_id , e.job_id;
</pre>
===SQL GROUP BY and DISTINCT===
<pre>
SELECT DISTINCT
phone_number
FROM
employees;
</pre>
<pre>

==Having==

<pre>
</pre>

{{Autor}}, gener 2022

@@ Línia 172: / Línia 172: @@
 </pre>
 ===Having vs WHERE. No és el mateix===
 {{Autor}}, gener 2022

@@ Línia 112: / Línia 112: @@
 ==Having==
 <pre>
 </pre>
 {{Autor}}, gener 2022

@@ Línia 110: / Línia 110: @@
 	employees;
 </pre>
 ==Having==