Funciones de agregado básicas

Análisis de series temporales en SQL Server

Maham Faisal Khan

Senior Data Science Content Developer

Funciones clave de agregación

Recuentos

COUNT()

COUNT_BIG()

COUNT(DISTINCT)

Otros agregados

SUM()

MIN()

MAX()

Qué cuenta con COUNT()

Número de filas

COUNT(*)

COUNT(1)

COUNT(1/0)

Valores no NULL

COUNT(d.YR)

COUNT(NULLIF(d.YR, 1990))

Recuentos distintos

SELECT
    COUNT(DISTINCT c.CalendarYear) AS Years,
    COUNT(DISTINCT NULLIF(c.CalendarYear, 2010)) AS Y2
FROM dbo.Calendar c;

Years	Y2
50	49

Filtrar agregados con CASE

SELECT
    MAX(CASE WHEN ir.IncidentTypeID = 1
            THEN ir.IncidentDate
            ELSE NULL
        END) AS I1,
    MAX(CASE WHEN ir.IncidentTypeID = 2
            THEN ir.IncidentDate
            ELSE NULL
        END) AS I2,
FROM dbo.IncidentRollup ir;

I1	I2
2020-06-30	2020-06-29

¡Vamos a practicar!

Análisis de series temporales en SQL Server