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

0 vote116 views1 answer
Group by two columns postgres
SQL
-1 vote132 views1 answer
Utf8_encode mysql
SQL
0 vote135 views1 answer
Vs 2019 connect to local mysql database
SQL
0 vote106 views1 answer
Sql server cannot create database diagram
SQL
-1 vote117 views1 answer
Module operator in oracle sql
SQL
0 vote116 views1 answer
Sql server separar numeros por comas miles
SQL
-1 vote121 views1 answer
Sql oracle take only last results
SQL
0 vote119 views1 answer
Sql count matching group by
SQL
0 vote114 views2 answers
Sql select inside select
SQL
0 vote115 views1 answer
Import sql dump into postgresql database
SQL