parse 运算符
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。 如果不需要使用分析不成功的行，则优先使用 parse-where 运算符。
语法
T | parse [ kind=kind [ flags=regexFlags ]] expression with [ * ] stringConstant columnName [: columnType] [ * ] , ...
详细了解语法约定。
参数
| 客户 | 类型 | 必需 | 说明 |
|---|---|---|---|
| T | string |
✔️ | 要分析的表格输入。 |
| kind | string |
✔️ | 支持的类型值之一。 默认值为 simple。 |
| regexFlags | string |
如果 kind 为 regex，则可以指定要使用的正则表达式标志，例如 U 表示 ungreedy，m 表示多行模式，s 表示匹配新行 \n，i 表示不区分大小写。 可以在标志中找到更多标志。 |
|
| expression | string |
✔️ | 计算结果为字符串的表达式。 |
| stringConstant | string |
✔️ | 要搜索和分析的字符串常量。 |
| columnName | string |
✔️ | 要为其赋值的列的名称（从字符串表达式中提取）。 |
| columnType | string |
一个标量值，指示要将值转换为何种类型。 默认为 string。 |
注意
- 除了 StringConstant 之外，分析模式还可以以 ColumnName 开头。
- 在模式中使用
*可跳过垃圾值。 不能在string类型列后使用*。 - 如果分析的表达式不是
string类型，则会将其转换为string类型。 - 如果还希望删除或重命名某些列，请使用
project。
支持的类型值
| 文本 | 说明 |
|---|---|
simple |
这是默认值。 stringConstant 是一个正则字符串值，匹配是严格的。 所有字符串分隔符都应出现在分析的字符串中，并且所有扩展列都必须与所需类型匹配。 |
regex |
stringConstant 可能是正则表达式，匹配要求较为严格。 所有字符串分隔符（对于此模式，可以是正则表达式）都应出现在分析的字符串中，并且所有扩展列都必须与所需类型匹配。 |
relaxed |
stringConstant 是一个正则字符串值，匹配是宽松的。 所有字符串分隔符都应出现在分析的字符串中，但是扩展列可能会部分匹配所需的类型。 与所需类型不匹配的扩展列将获得值 null。 |
正则表达式模式
在正则表达式模式下，分析会将模式转换为正则表达式。 请使用正则表达式进行匹配，并使用在内部处理的带编号的已捕获组。 例如：
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+。
返回
输入表，根据提供给运算符的列的列表进行扩展。
示例
parse 运算符提供了一种简单的方法，可通过对同一 string 表达式使用多个 extract 应用程序来 extend 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 Traces 的列 EventText 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
输出
| resourceName | totalSlices | sliceNumber | lockTime | releaseTime | previousLockTime |
|---|---|---|---|---|---|
| PipelineScheduler | 27 | 15 | 02/17/2016 08:40:00 | 2016-02-17 08:40:00.0000000 | 2016-02-17 08:39:00.0000000 |
| PipelineScheduler | 27 | 23 | 02/17/2016 08:40:01 | 2016-02-17 08:40:01.0000000 | 2016-02-17 08:39:01.0000000 |
| 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 | 16 | 02/17/2016 08:41:00 | 2016-02-17 08:41:00.0000000 | 2016-02-17 08:40:00.0000000 |
| PipelineScheduler | 27 | 22 | 02/17/2016 08:41:01 | 2016-02-17 08:41:00.0000000 | 2016-02-17 08:40:01.0000000 |
提取电子邮件别名和 DNS
在以下示例中，将分析联系人表中的条目，以便从电子邮件地址中提取别名和域，并从网站 URL 中提取域。 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
输出
| EmailAddress | EmailAlias | WebsiteDomain |
|---|---|---|
| nevena@treyresearch.com | nevena | treyresearch.com |
| john@contosohotel.com | john | contosohotel.com |
| faruk@tailspintoys.com | faruk | tailspintoys.com |
| ebere@relecloud.com | ebere | relecloud.com |
| abi@fourthcoffee.com | abi | www.fourthcoffee.com |
正则表达式模式
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
输出
| resourceName | sliceNumber | lockTime | releaseTime | previousLockTime |
|---|---|---|---|---|
| PipelineScheduler | 15 | 02/17/2016 08:40:00, | 02/17/2016 08:40:00, | 2016-02-17 08:39:00.0000000 |
| PipelineScheduler | 23 | 02/17/2016 08:40:01, | 02/17/2016 08:40:01, | 2016-02-17 08:39:01.0000000 |
| PipelineScheduler | 20 | 02/17/2016 08:40:01, | 02/17/2016 08:40:01, | 2016-02-17 08:39:01.0000000 |
| PipelineScheduler | 16 | 02/17/2016 08:41:00, | 02/17/2016 08:41:00, | 2016-02-17 08:40:00.0000000 |
| PipelineScheduler | 22 | 02/17/2016 08:41:01, | 02/17/2016 08:41:00, | 2016-02-17 08:40:01.0000000 |
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
输出
| resourceName |
|---|
| PipelineScheduler, totalSlices=27, sliceNumber=23, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01 |
| PipelineScheduler, totalSlices=27, sliceNumber=15, lockTime=02/17/2016 08:40:00, releaseTime=02/17/2016 08:40:00 |
| PipelineScheduler, totalSlices=27, sliceNumber=20, lockTime=02/17/2016 08:40:01, releaseTime=02/17/2016 08:40:01 |
| PipelineScheduler, totalSlices=27, sliceNumber=22, lockTime=02/17/2016 08:41:01, releaseTime=02/17/2016 08:41:00 |
| PipelineScheduler, totalSlices=27, sliceNumber=16, lockTime=02/17/2016 08:41:00, releaseTime=02/17/2016 08:41:00 |
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
输出
| resourceName |
|---|
| PipelineScheduler |
| PipelineScheduler |
| PipelineScheduler |
| PipelineScheduler |
| PipelineScheduler |
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
输出
| resourceName | totalSlices | lockTime | releaseTime | previousLockTime |
|---|---|---|---|---|
| PipelineScheduler |
27 | 2016-02-17 08:40:00.0000000 | 2016-02-17 08:40:00.0000000 | 2016-02-17 08:39:00.0000000 |
| PipelineScheduler |
27 | 2016-02-17 08:40:01.0000000 | 2016-02-17 08:40:01.0000000 | 2016-02-17 08:39:01.0000000 |
| PipelineScheduler |
27 | 2016-02-17 08:40:01.0000000 | 2016-02-17 08:40:01.0000000 | 2016-02-17 08:39:01.0000000 |
| PipelineScheduler |
27 | 2016-02-17 08:41:00.0000000 | 2016-02-17 08:41:00.0000000 | 2016-02-17 08:40:00.0000000 |
| PipelineScheduler |
27 | 2016-02-17 08:41:01.0000000 | 2016-02-17 08:41:00.0000000 | 2016-02-17 08:40:01.0000000 |
Relaxed 模式
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。
注意
在 relaxed 模式下，可以对扩展列进行部分匹配。
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
输出
| resourceName | totalSlices | sliceNumber | lockTime | releaseTime | previousLockTime |
|---|---|---|---|---|---|
| PipelineScheduler | 27 | 15 | 02/17/2016 08:40:00 | 2016-02-17 08:39:00.0000000 | |
| PipelineScheduler | 27 | 23 | 02/17/2016 08:40:01 | 2016-02-17 08:39:01.0000000 | |
| PipelineScheduler | 20 | 02/17/2016 08:40:01 | 2016-02-17 08:39:01.0000000 | ||
| PipelineScheduler | 16 | 02/17/2016 08:41:00 | 2016-02-17 08:41:00.0000000 | 2016-02-17 08:40:00.0000000 | |
| PipelineScheduler | 27 | 22 | 02/17/2016 08:41:01 | 2016-02-17 08:41:00.0000000 | 2016-02-17 08:40:01.0000000 |