Count 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 join

-- Rows with ID existing in both a, b and c
-- JOIN is equivalent to INNER JOIN
SELECT a.ID, a.NAME, b.VALUE1, c.VALUE1 FROM table1 a 
  JOIN table2 b ON a.ID = b.ID
  JOIN table3 c ON a.ID = c.ID
WHERE a.ID >= 1000;
-- ⇓ Test it ⇓ (Fiddle source link)

Source: sqlfiddle.com

Count sql

SELECT COUNT(column_name)
FROM table_name
WHERE condition;

Counting in sql

SELECT COUNT(*) FROM EMPLOYEES;

Similar codes

1 vote183 views1 answer
Postgresql if 0 then 1
SQL
7 votes154 views3 answers
Foreign key oracle
SQL
0 vote140 views1 answer
Postgresql heritage
SQL
9 votes144 views3 answers
Sql delete where in
SQL
1 vote149 views1 answer
Age postgres
SQL
0 vote138 views1 answer
18446744073709551615 mariadb left join order by
SQL
23 votes147 views4 answers
Sql server substring
SQL
18 votes181 views3 answers
Get the list of all tables in sql server
SQL
0 vote147 views2 answers
Mysql multiply
SQL
0 vote104 views3 answers
Mysql calculate age from date of birth
SQL