parse operator

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

计算字符串表达式并将其值分析为一个或多个计算列。 已计算列将针对未成功分析的字符串返回 null 值。 If there's no need to use rows where parsing doesn't succeed, prefer using the parse-where operator.

Syntax

T| parse [ kind=kind [ flags=regexFlags ]] expressionwith [ * ] stringConstantcolumnName [:columnType] [ * ] , ...

Learn more about syntax conventions.

Parameters

支持的 kind 值

Regex mode

在正则表达式模式下，分析会将模式转换为正则表达式。 Use regular expressions to do the matching and use numbered captured groups that are handled internally. For example:

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

在分析语句中，分析内部生成的正则表达式是 .*?<regex1>(.*?)<regex2>(\-\d+)。

• * 转换为 .*?。

• string 转换为 .*?。

• long 转换为 \-\d+。

Returns

输入表，根据提供给运算符的列的列表进行扩展。

Examples

本节中的示例演示如何使用语法帮助你入门。

parse 运算符提供了一种简单的方法，可通过对同一 extend 表达式使用多个 extract 应用程序来 string 表。 当表中有一个 string 列，其中包含多个要分解为单独列的值时，此结果非常有用。 例如，由开发人员跟踪 ("printf"/"Console.WriteLine") 语句生成的列。

分析和扩展结果

在以下示例中，表 EventText 的列 Traces 包含 Event: NotifySliceRelease (resourceName={0}, totalSlices={1}, sliceNumber={2}, lockTime={3}, releaseTime={4}, previousLockTime={5}) 形式的字符串。 该操作使用六列扩展表：resourceName、totalSlices、sliceNumber、lockTime、releaseTime 和 previousLockTime。

let Traces = datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=23, 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=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=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 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

提取电子邮件别名和 DNS

In the following example, entries from the Contacts table are parsed to extract the alias and domain from an email address, and the domain from a website URL. 查询会返回 EmailAddress、EmailAlias 和 WebsiteDomain 列，其中 fullEmail 列会合并分析的电子邮件别名和域。

let Leads=datatable(Contacts: string)
    [
    "Event: LeadContact (email=john@contosohotel.com, Website=https:contosohotel.com)",
	"Event: LeadContact (email=abi@fourthcoffee.com, Website=https:www.fourthcoffee.com)",
	"Event: LeadContact (email=nevena@treyresearch.com, Website=https:treyresearch.com)",
	"Event: LeadContact (email=faruk@tailspintoys.com, Website=https:tailspintoys.com)",
	"Event: LeadContact (email=ebere@relecloud.com, Website=https:relecloud.com)",
];
Leads
| parse Contacts with * "email=" alias:string "@" domain: string ", Website=https:" WebsiteDomain: string ")"
| project EmailAddress=strcat(alias, "@", domain), EmailAlias=alias, WebsiteDomain

Output

Regex mode

在下面的示例中，正则表达式用于分析和提取 EventText 列中的数据。 提取的数据会投影到新字段中。

let Traces=datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=23, 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=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=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 kind=regex EventText with "(.*?)[a-zA-Z]*=" resourceName @", totalSlices=\s*\d+\s*.*?sliceNumber=" sliceNumber: long  ".*?(previous)?lockTime=" lockTime ".*?releaseTime=" releaseTime ".*?previousLockTime=" previousLockTime: date "\\)"  
| project resourceName, sliceNumber, lockTime, releaseTime, previousLockTime

Output

使用正则表达式标志的正则表达式模式

在以下示例中，提取了 resourceName。

let Traces=datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=23, 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=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=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 kind=regex EventText with * "resourceName=" resourceName ',' *
| project resourceName

Output

如果有些记录在 resourceName 中有时显示为小写，有时显示为大写，则某些值可能会获得 null。

上一示例中的结果是意外结果，并且包括完整的事件数据，因为默认模式是贪婪的。 要仅提取 resourceName，请使用非贪婪 U 运行上一个查询，并禁用区分大小写的 i 正则表达式标志。

let Traces=datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=23, 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=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=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 kind=regex flags=Ui EventText with * "RESOURCENAME=" resourceName ',' *
| project resourceName

Output

如果分析的字符串具有换行符，请使用标志 s 来分析文本。

let Traces=datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler\ntotalSlices=27\nsliceNumber=23\nlockTime=02/17/2016 08:40:01\nreleaseTime=02/17/2016 08:40:01\npreviousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler\ntotalSlices=27\nsliceNumber=15\nlockTime=02/17/2016 08:40:00\nreleaseTime=02/17/2016 08:40:00\npreviousLockTime=02/17/2016 08:39:00)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler\ntotalSlices=27\nsliceNumber=20\nlockTime=02/17/2016 08:40:01\nreleaseTime=02/17/2016 08:40:01\npreviousLockTime=02/17/2016 08:39:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler\ntotalSlices=27\nsliceNumber=22\nlockTime=02/17/2016 08:41:01\nreleaseTime=02/17/2016 08:41:00\npreviousLockTime=02/17/2016 08:40:01)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler\ntotalSlices=27\nsliceNumber=16\nlockTime=02/17/2016 08:41:00\nreleaseTime=02/17/2016 08:41:00\npreviousLockTime=02/17/2016 08:40:00)"
];
Traces
| parse kind=regex flags=s EventText with * "resourceName=" resourceName: string "(.*?)totalSlices=" totalSlices: long "(.*?)lockTime=" lockTime: datetime "(.*?)releaseTime=" releaseTime: datetime "(.*?)previousLockTime=" previousLockTime: datetime "\\)" 
| project-away EventText

Output

Relaxed mode

在以下相关模式示例中，扩展列 totalSlices 必须为类型 long。 但是，在分析的字符串中，它的值是 nonValidLongValue。 对于扩展列 releaseTime，不能将 nonValidDateTime 值分析为 datetime。 这两个扩展列会产生 null 值，而其他列（例如 sliceNumber）仍会产生正确的值。

如果对以下查询使用选项 kind = simple，则会获得所有扩展列的 null 结果。 此选项在扩展列上是严格的，这是 relaxed 模式和 simple 模式之间的差异。

let Traces=datatable(EventText: string)
    [
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=27, sliceNumber=23, lockTime=02/17/2016 08:40:01, releaseTime=nonValidDateTime 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=nonValidDateTime, previousLockTime=02/17/2016 08:39:00)",
    "Event: NotifySliceRelease (resourceName=PipelineScheduler, totalSlices=nonValidLongValue, sliceNumber=20, lockTime=02/17/2016 08:40:01, releaseTime=nonValidDateTime 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=nonValidLongValue, 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 kind=relaxed EventText with * "resourceName=" resourceName ", totalSlices=" totalSlices: long ", sliceNumber=" sliceNumber: long * "lockTime=" lockTime ", releaseTime=" releaseTime: date "," * "previousLockTime=" previousLockTime: date ")" *
| project-away EventText

Output

Related content

• parse-json function
• extract function
• extract-all function
• extract-json function