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parse-where operator

Applies to: ✅Microsoft Fabric✅Azure Data Explorer✅Azure Monitor✅Microsoft Sentinel

Evalúa una expresión de cadena y analiza su valor en una o varias columnas calculadas. El resultado es solo las cadenas analizadas correctamente.

parse-where parses the strings in the same way as parse, and filters out strings that were not parsed successfully.

See parse operator, which produces nulls for unsuccessfully parsed strings.

Syntax

T| parse-where [kind=kind [flags=regexFlags]] expressionwith* (stringConstantcolumnName [:columnType]) *...

Learn more about syntax conventions.

Parameters

Name Type Required Description
T string ✔️ Entrada tabular que se va a analizar.
kind string ✔️ Uno de los valores de tipo admitidos. El valor predeterminado es simple.
regexFlags string If kind is regex, then you can specify regex flags to be used like U for ungreedy, m for multi-line mode, s for match new line \n, and i for case-insensitive. More flags can be found in Flags.
expression string ✔️ expresión que se evalúa como una cadena.
stringConstant string ✔️ Constante de cadena para la que buscar y analizar.
columnName string ✔️ nombre de una columna a la que se va a asignar un valor, extraído de la expresión de cadena.
columnType string El valor escalar que indica el tipo al que se convertirá el valor. string es el valor predeterminado.

Note

  • Use project if you also want to drop or rename some columns.
  • Use * en el patrón para omitir los valores no deseados. Este valor no se puede usar después string de la columna.
  • The parse pattern may start with ColumnName, in addition to StringConstant.
  • If the parsed expression isn't of type string, it will be converted to type string.

Valores de tipo admitidos

Text Description
simple Este es el valor predeterminado. stringConstant is a regular string value and the match is strict. Todos los delimitadores de cadena deben aparecer en la cadena analizada, y todas las columnas extendidas deben coincidir con los tipos necesarios.
regex stringConstant may be a regular expression and the match is strict. Todos los delimitadores de cadena, que pueden ser una expresión regular para este modo, deben aparecer en la cadena analizada, y todas las columnas extendidas deben coincidir con los tipos necesarios.

Regex mode

In regex mode, parse will translate the pattern to a regex and use regular expressions in order to do the matching using numbered captured groups that are handled internally. For example:

parse-where kind=regex Col with * <regex1> var1:string <regex2> var2:long

La expresión regular que generará el análisis internamente es .*?<regex1>(.*?)<regex2>(\-\d+).

  • * se tradujo a .*?.
  • string se tradujo a .*?.
  • long se tradujo a \-\d+.

Returns

Tabla de entrada, que se extiende según la lista de columnas que se proporcionan al operador.

Note

Solo las cadenas analizadas correctamente estarán en la salida. Las cadenas que no coinciden con el patrón se filtrarán.

Examples

Los ejemplos de esta sección muestran cómo usar la sintaxis para ayudarle a empezar.

The examples in this article use publicly available tables in the help cluster, such as the StormEvents table in the Samples database.

The examples in this article use publicly available tables, such as the Weather table in the Weather analytics sample gallery. Es posible que tenga que modificar el nombre de la tabla en la consulta de ejemplo para que coincida con la tabla del área de trabajo.

El operador parse-where proporciona una manera simplificada de aplicar extend a una tabla mediante el uso de varias aplicaciones extract en la misma expresión de string. Esto resulta más útil cuando la tabla tiene una string columna que contiene varios valores que desea dividir en columnas individuales. Por ejemplo, puede dividir una columna generada por una instrucción de seguimiento del desarrollador (""printf/"Console.WriteLine").

Usar parse

En el ejemplo siguiente, la columna EventText de la tabla Traces contiene cadenas del formulario Event: NotifySliceRelease (resourceName={0}, totalSlices= {1}, sliceNumber={2}, lockTime={3}, releaseTime={4}, previousLockTime={5}). La operación siguiente extenderá la tabla con seis columnas: resourceName , , totalSlicessliceNumberlockTime, releaseTime, , previousLockTime, , Monthy Day.

Algunas de las cadenas no tienen una coincidencia completa.

Con parse, las columnas calculadas tendrán valores NULL.

Ejecución de la consulta

let Traces = datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=invalid_number, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=15, lockTime=02/17/2016 08:40:00, releaseTime=invalid_datetime, previousLockTime=02/17/2016 08:39:00)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=20, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=22, lockTime=02/17/2016 08:41:01, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=invalid_number, sliceNumber=16, lockTime=02/17/2016 08:41:00, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:00)"
];
Traces  
| parse EventText with * "resourceName=" resourceName ", totalSlices=" totalSlices: long * "sliceNumber=" sliceNumber: long * "lockTime=" lockTime ", releaseTime=" releaseTime: date "," * "previousLockTime=" previouLockTime: date ")" *  
| project
    resourceName,
    totalSlices,
    sliceNumber,
    lockTime,
    releaseTime,
    previouLockTime

Output

resourceName totalSlices sliceNumber lockTime releaseTime previousLockTime
PipelineScheduler 27 20 02/17/2016 08:40:01 2016-02-17 08:40:01.0000000 2016-02-17 08:39:01.0000000
PipelineScheduler 27 22 02/17/2016 08:41:01 2016-02-17 08:41:00.0000000 2016-02-17 08:40:01.0000000

Usar parse-where

El uso de "parse-where" filtrará las cadenas analizadas incorrectamente del resultado.

Ejecución de la consulta

let Traces = datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=invalid_number, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=15, lockTime=02/17/2016 08:40:00, releaseTime=invalid_datetime, previousLockTime=02/17/2016 08:39:00)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=20, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=22, lockTime=02/17/2016 08:41:01, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=invalid_number, sliceNumber=16, lockTime=02/17/2016 08:41:00, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:00)"
];
Traces  
| parse-where EventText with * "resourceName=" resourceName ", totalSlices=" totalSlices: long * "sliceNumber=" sliceNumber: long * "lockTime=" lockTime ", releaseTime=" releaseTime: date "," * "previousLockTime=" previousLockTime: date ")" *  
| project
    resourceName,
    totalSlices,
    sliceNumber,
    lockTime,
    releaseTime,
    previousLockTime

Output

resourceName totalSlices sliceNumber lockTime releaseTime previousLockTime
PipelineScheduler 27 20 02/17/2016 08:40:01 2016-02-17 08:40:01.0000000 2016-02-17 08:39:01.0000000
PipelineScheduler 27 22 02/17/2016 08:41:01 2016-02-17 08:41:00.0000000 2016-02-17 08:40:01.0000000

Modo Regex mediante marcas regex

Para obtener resourceName y totalSlices, use la siguiente consulta:

Ejecución de la consulta

let Traces = datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=non_valid_integer, sliceNumber=11, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=15, lockTime=02/17/2016 08:40:00, releaseTime=02/17/2016 08:40:00, previousLockTime=02/17/2016 08:39:00)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=non_valid_integer, sliceNumber=44, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=22, lockTime=02/17/2016 08:41:01, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=16, lockTime=02/17/2016 08:41:00, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:00)"
];
Traces
| parse-where kind = regex EventText with * "RESOURCENAME=" resourceName "," * "totalSlices=" totalSlices: long "," *
| project resourceName, totalSlices

Output

resourceName totalSlices

parse-where con la marca regex sin distinción entre mayúsculas y minúsculas

En la consulta anterior, el modo predeterminado distingue mayúsculas de minúsculas, por lo que las cadenas se analizaron correctamente. No se obtuvo ningún resultado.

Para obtener el resultado necesario, ejecute parse-where con una marca regex sin distinción entre mayúsculas y minúsculas (i).

Solo se analizarán correctamente tres cadenas, por lo que el resultado es tres registros (algunos totalSlices contienen enteros no válidos).

Ejecución de la consulta

let Traces = datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=non_valid_integer, sliceNumber=11, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=15, lockTime=02/17/2016 08:40:00, releaseTime=02/17/2016 08:40:00, previousLockTime=02/17/2016 08:39:00)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=non_valid_integer, sliceNumber=44, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01, previousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=22, lockTime=02/17/2016 08:41:01, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=16, lockTime=02/17/2016 08:41:00, releaseTime=02/17/2016 08:41:00, previousLockTime=02/17/2016 08:40:00)"
];
Traces
| parse-where kind = regex flags=i EventText with * "RESOURCENAME=" resourceName "," * "totalSlices=" totalSlices: long "," *
| project resourceName, totalSlices

Output

resourceName totalSlices
PipelineScheduler 27
PipelineScheduler 27
PipelineScheduler 27
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