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 vote151 views2 answers
Get value from a table an insert it with other values in another table sql
SQL
0 vote126 views1 answer
Alter precision
SQL
0 vote116 views1 answer
Netstat -tln mysql
SQL
0 vote118 views1 answer
C# mysql data reader from two tables
SQL
2 votes126 views2 answers
Select list is not in group by clause
SQL
4 votes122 views2 answers
Sql vs mysql
SQL
0 vote141 views1 answer
Create query in where clasue
SQL
1 vote129 views1 answer
Oracle create as select
SQL
4 votes139 views1 answer
For loop postgresql
SQL
3 votes135 views5 answers
Sql select
SQL