DA SQL a Linguaggio di query Kusto foglio informativo

Si applica a: ✅Microsoft Fabric✅Azure Esplora dati✅ Azure Monitor✅Microsoft Sentinel

Se si ha familiarità con SQL e si vuole apprendere KQL, convertire le query SQL in KQL anteponendo la query SQL con una riga di commento, --e la parola chiave explain. L'output mostra la versione KQL della query, che consente di comprendere la sintassi e i concetti di KQL.

Eseguire la query

--
explain
SELECT COUNT_BIG(*) as C FROM StormEvents 

Output

Query
StormEvents<br>| summarize C=count()<br>| project C

Scheda di riferimento rapido sul passaggio da SQL a Kusto

La tabella seguente illustra le query di esempio in SQL e i relativi equivalenti KQL.

Categoria	Query SQL	Query Kusto	Altre informazioni
Selezione di dati da una tabella	SELECT * FROM dependencies	dependencies	Istruzioni di espressione tabulare
--	SELECT name, resultCode FROM dependencies	dependencies | project name, resultCode	project
--	SELECT TOP 100 * FROM dependencies	dependencies | take 100	take
Valutazione null	SELECT * FROM dependencies WHERE resultCode IS NOT NULL	dependencies | where isnotnull(resultCode)	isnotnull()
Operatori di confronto (data)	SELECT * FROM dependencies WHERE timestamp > getdate()-1	dependencies | where timestamp > ago(1d)	ago()
--	SELECT * FROM dependencies WHERE timestamp BETWEEN ... AND ...	dependencies | where timestamp between (datetime(2016-10-01) .. datetime(2016-11-01))	tra
Operatori di confronto (stringa)	SELECT * FROM dependencies WHERE type = "Azure blob"	dependencies | where type == "Azure blob"	Operatori logici
--	-- substring SELECT * FROM dependencies WHERE type like "%blob%"	// substring dependencies | where type has "blob"	ha
--	-- wildcard SELECT * FROM dependencies WHERE type like "Azure%"	// wildcard dependencies | where type startswith "Azure" // or dependencies | where type matches regex "^Azure.*"	startswith matches regex
Confronto (booleano)	SELECT * FROM dependencies WHERE !(success)	dependencies | where success == False	Operatori logici
Raggruppamento, aggregazioni	SELECT name, AVG(duration) FROM dependencies GROUP BY name	dependencies | summarize avg(duration) by name	summarize avg()
Distinct	SELECT DISTINCT name, type FROM dependencies	dependencies | distinct name, type	summarize distinct
--	SELECT name, COUNT(DISTINCT type) FROM dependencies GROUP BY name	dependencies | summarize by name, type | summarize count() by name // or approximate for large sets dependencies | summarize dcount(type) by name	count() dcount()
Alias di colonna, estensioni	SELECT operationName as Name, AVG(duration) as AvgD FROM dependencies GROUP BY name	dependencies | summarize AvgD = avg(duration) by Name=operationName	Istruzione Alias
--	SELECT conference, CONCAT(sessionid, ' ' , session_title) AS session FROM ConferenceSessions	ConferenceSessions | extend session=strcat(sessionid, " ", session_title) | project conference, session	strcat() project
Creazione dell'ordine	SELECT name, timestamp FROM dependencies ORDER BY timestamp ASC	dependencies | project name, timestamp | sort by timestamp asc nulls last	ordinamento
Primi n in base a misura	SELECT TOP 100 name, COUNT(*) as Count FROM dependencies GROUP BY name ORDER BY Count DESC	dependencies | summarize Count = count() by name | top 100 by Count desc	top
Union	SELECT * FROM dependencies UNION SELECT * FROM exceptions	union dependencies, exceptions	union
--	SELECT * FROM dependencies WHERE timestamp > ... UNION SELECT * FROM exceptions WHERE timestamp > ...	dependencies | where timestamp > ago(1d) | union (exceptions | where timestamp > ago(1d))
Join.	SELECT * FROM dependencies LEFT OUTER JOIN exceptions ON dependencies.operation_Id = exceptions.operation_Id	dependencies | join kind = leftouter (exceptions) on $left.operation_Id == $right.operation_Id	join
Query nidificate	SELECT * FROM dependencies WHERE resultCode == (SELECT TOP 1 resultCode FROM dependencies WHERE resultId = 7 ORDER BY timestamp DESC)	dependencies | where resultCode == toscalar( dependencies | where resultId == 7 | top 1 by timestamp desc | project resultCode)	toscalar
Having	SELECT COUNT(\*) FROM dependencies GROUP BY name HAVING COUNT(\*) > 3	dependencies | summarize Count = count() by name | where Count > 3	riepilogare dove

Contenuto correlato

• Usare T-SQL per eseguire query sui dati