返回选择语句SQL的最大值

Question

I pretty much forgot how to do this with SQL actually, the thing is I have an SQL select statement such as:

SELECT COUNT(*) NAME FROM `SomeTable` WHERE `SomeID` = xxx GROUP BY `Field`

Which does return a table with one field and many records containing numbers. What I want is to get the a single value of the maximum number among those records.

Answer 1

it should help you. just use MAX() function

SELECT MAX(COUNT(*)) FROM `SomeTable` WHERE `SomeID` = xxx GROUP BY `Field`

Answer 2

只需添加LIMIT：

SELECT COUNT(`NAME`) AS `NUM` FROM `SomeTable` WHERE `SomeID` = xxx GROUP BY `Field` ORDER BY `NUM`  DESC LIMIT 1

Answer 3

select max(name) from
(
SELECT COUNT(*) NAME FROM `SomeTable` WHERE `SomeID` = xxx GROUP BY `Field`)a

Answer 4

SELECT COUNT(*) NAME 
FROM `SomeTable` 
WHERE `SomeID` = xxx 
GROUP BY `Field`
order by NAME desc
limit 1

Answer 5

I want is to get the a single value of the maximum number among those records.

Try this:

SELECT t1.*
FROM SomeTable t1
(
     SELECT SomeID, Max(Field) MaxField
     FROM SomeTable
     GROUP BY SomeID
) t2 ON t1.SomeID = t2.SomeID AND t1.Field = t2.MaxField
WHERE t1.SomeID = xxx

Answer 6

If you just want a single result of the highest value against a filter, just use Max:

SELECT MAX(MyField) NAME 
FROM `SomeTable` 
WHERE `SomeID` = xxx;

Alternatively, if you want an aggregate grouped by another column, the syntax is like so:

SELECT Name, MAX(MyField) as MaxOfMyField -- Or COUNT(MyField) if you want the Count
FROM `SomeTable` 
WHERE `SomeID` = xxx 
GROUP By Name;

Answer 7

The syntax for the MAX function is:

SELECT MAX(expression )
FROM tables
WHERE predicates;

Example

SELECT MAX(salary) as "Highest salary"
FROM employees;