Usage of groupby in sqlserver

Welcome to the Windows community forum and interact with 3 million technical staff. Each predicate compares the group features (such as AVG (SALARY) with one of the following features: HAVINGAVG (SALARY) 2 * MIN (SALARY) constant for example: HAVINGAVG (SALARY) 20000 for example, the following query finds the number of employees that exceed

Welcome to the Windows community forum, and interact with 3 million technical staff> enter each predicate to compare the group features (such as AVG (SALARY) with one of the following, for example: having avg (SALARY) 2 * MIN (SALARY) constant for example: having avg (SALARY) 20000 for example, the following query finds the number of employees exceeds

Welcome to the Windows community forum and interact with 3 million technicians>

Each predicate compares a group feature (for example, AVG (SALARY) with one of the following, for example, having avg (SALARY)> 2 * MIN (SALARY) constants.

For example: having avg (SALARY)> 20000

For example, the following query queries the highest and lowest salaries of departments with more than 4 employees:

Code example: select workdept, MAX (SALARY) as maximum, MIN (SALARY) AS MINIMUM

FROM EMPLOYEE

GROUP BY WORKDEPT

Having count (*)> 4 ORDER BY WORKDEPT

Result:

WORKDEPT MAXIMUM MINIMUM

------------------------------

D11 32250.00 18270.00

D21 36170.00 17250.00

E11 29750.00 15340.00

It is possible (though rare) that a query has a HAVING clause but does not have a group by clause. In this case, DB2 regards the entire table as a group. Because the table is regarded as a single group, there can be a maximum of one result row. If the HAVING condition is true for the entire table, the selected result is returned (the result must be composed of column functions); otherwise, no rows are returned. Officially speaking, group-based operations, or better understanding, are class-based operations.

Use the following example to deepen your understanding.

The table is as follows:

Code example: ID name warehouse quantity

01 watermelon 1 10

02 watermelon 2 30

03 rice 1 30

04 Apple 1 40

05 Apple 2 45

06 apple 3 5

Statement:

Code example: Select name, Sun (price) From Table Group By name

Returns the total number of items, no matter which warehouse

Result:

Watermelon, 40

Rice, 30

Apple, 90

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