Average sql

Sql count

/*COUNT(column_name) will return the number of rows from the column 
that are not NULL*/
SELECT COUNT(column_name)
FROM table_name;

/*COUNT(*) will return the number of rows from the table*/
SELECT COUNT(*)
FROM table_name;

Sql average

SELECT student_name, avg(notes) FROM student_notes GROUP BY student_name;

How to find average in sql

SELECT FIRST_NAME FROM EMPLOYEES
WHERE SALARY = (SELECT AVG(SALARY) FROM EMPLOYEES);

Similar codes

6 votes435 views2 answers
Oracle compile trigger
SQL
0 vote364 views1 answer
Sql count matching group by
SQL
1 vote365 views1 answer
Oracle sequence last_number
SQL
23 votes365 views3 answers
Sql where contains part of string
SQL
1 vote350 views1 answer
Oracle create as select
SQL
17 votes356 views6 answers
MySQL ORDER BY
SQL
0 vote358 views1 answer
Mysql master slave setup with keepalived
SQL
0 vote342 views1 answer
Sql offfset
SQL
1 vote360 views1 answer
Mariadb case switch
SQL
15 votes416 views3 answers
Mysql update add to existing value
SQL