April 2025
Beginner to intermediate
310 pages
8h 37m
Portuguese (Portugal, Brazil)
Content preview from Aprende a usar o Microsoft Power BI
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Apêndice A. Expressões DAX comumente usadas
Neste apêndice, irei rever a sintaxe de algumas das funções DAX mais utilizadas no Power BI. Estas estão organizadas por secção e depois por ordem alfabética dentro dessa secção. Para cada função, apresenta uma breve descrição do objetivo da função, a sintaxe da função e, em seguida, um exemplo utilizando essa sintaxe.
Esta não é uma lista exaustiva de todas as funções da linguagem DAX. Podes consultá-la em "Referência de funções DAX".
Tal como acontece com muitas coisas, o DAX é um excelente exemplo do princípio de Pareto: 80% de todos os problemas (resultados) podem ser resolvidos com 20% de domínio (entradas).
Funções de agregação
MÉDIA
Definição
Devolve a média de todos os valores numéricos de uma coluna.
Sintaxe
AVERAGE ( [ColumnName] )
Exemplo
AverageScore = AVERAGE ( GradeScore[Score] )
AVERAGEX
Definição
Calcula a média de um conjunto de expressões avaliadas em cada linha de uma tabela.
Sintaxe
AVERAGEX ( 'TableName' , <expression> )
Exemplo
AverageScorePercentage = AVERAGEX ( 'GradeScores', 'GradeScores'[Score] + 'GradeScores'[MaximumPossibleScore] )
CONTAR
Definição
Devolve o número de registos de uma coluna que não estão em branco.
Sintaxe
COUNT ( [ColumnName] )
Exemplo
CountOfStudents = COUNT ( 'UniversitySuppliedData'[StudentID] )
DISTINCTCOUNT
Definição
Devolve o número de valores distintos para uma determinada coluna.
Sintaxe
DISTINCTCOUNT ( [ColumnName] )
Exemplo
CountOfStudents ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.