$regexFindAll (operador de expressão )

Devoluções

O operador retorna uma array:

• Se o operador não encontrar uma correspondência, o operador retornará uma array vazia.

• Se o operador encontrar uma correspondência, o operador retornará uma array de documentos que contém as seguintes informações para cada correspondência:

  • a string correspondente na entrada,

  • o índice ponto de código (não índice de bytes) da string correspondente na entrada, e

  • Uma array de strings que corresponde aos grupos capturados pela string correspondente. Os grupos de captura são especificados com parênteses comuns () no padrão regex.

  [ { "match" : <string>, "idx" : <num>, "captures" : <array of strings> }, ... ]
  

Biblioteca CRE

A partir da versão 6.1, o MongoDB usa a biblioteca PCRE2 (Perl Compatible Regular Expressions) para implementar a correspondência de padrões de expressão regular. Para saber mais sobre PCRE2, consulte a documentação do PCRE.

$regexFindAll e Agrupamento

a correspondência de strings para $regexFindAll sempre diferencia maiúsculas, minúsculas e diacríticos. $regexFindAll ignora o agrupamento especificado para a coleção, db.collection.aggregate() e o índice, se utilizado.

Por exemplo, crie uma collection com força de agrupamento 1, o que significa que o agrupamento compara apenas caracteres básicos e ignora diferenças como letras maiúsculas, letras minúsculas e diacríticos:

db.createCollection( "restaurants", { collation: { locale: "fr", strength: 1 } } )

Insira os seguintes documentos:

db.restaurants.insertMany( [
   { _id: 1, category: "café", status: "Open" },
   { _id: 2, category: "cafe", status: "open" },
   { _id: 3, category: "cafE", status: "open" }
] )

O seguinte usa o agrupamento da coleção para realizar uma correspondência insensível a maiúsculas e minúsculas e insensível a diacríticos:

db.restaurants.aggregate( [ { $match: { category: "cafe" } } ] )

[
   { _id: 1, category: 'café', status: 'Open' },
   { _id: 2, category: 'cafe', status: 'open' },
   { _id: 3, category: 'cafE', status: 'open' }
]

No entanto, $regexFindAll ignora o agrupamento. Os exemplos de correspondência de padrão de expressão regular a seguir diferenciam maiúsculas de minúsculas e diacríticos:

db.restaurants.aggregate( [
   {
      $addFields: {
         resultObject: { $regexFindAll: { input: "$category", regex: /cafe/ } }
      }
   }
] )
db.restaurants.aggregate( [
   {
      $addFields: {
         resultObject: { $regexFindAll: { input: "$category", regex: /cafe/ } }
      }
   }
],
   { collation: { locale: "fr", strength: 1 } } // Ignored in the $regexFindAll
)

Ambas as operações retornam o seguinte:

{ "_id" : 1, "category" : "café", "resultObject" : null }
{ "_id" : 2, "category" : "cafe", "resultObject" : { "match" : "cafe", "idx" : 0, "captures" : [ ] } }
{ "_id" : 3, "category" : "cafE", "resultObject" : null }

Como a query ignora o agrupamento, ela exige uma correspondência exata na string category (incluindo maiúsculas e minúsculas e acentos), o que significa que somente o documento _id: 2 corresponde.

To perform a case-insensitive regex pattern matching, use the i Option instead. See i Option for an example.

captures Comportamento de Saída

If your regex pattern contains capture groups and the pattern finds a match in the input, the captures array in the results corresponds to the groups captured by the matching string. Capture groups are specified with unescaped parentheses () in the regex pattern. The length of the captures array equals the number of capture groups in the pattern and the order of the array matches the order in which the capture groups appear.

Crie uma coleção de amostra denominada contacts com os seguintes documentos:

db.contacts.insertMany([
  { "_id": 1, "fname": "Carol", "lname": "Smith", "phone": "718-555-0113" },
  { "_id": 2, "fname": "Daryl", "lname": "Doe", "phone": "212-555-8832" },
  { "_id": 3, "fname": "Polly", "lname": "Andrews", "phone": "208-555-1932" },
  { "_id": 4, "fname": "Colleen", "lname": "Duncan", "phone": "775-555-0187" },
  { "_id": 5, "fname": "Luna", "lname": "Clarke", "phone": "917-555-4414" }
])

The following pipeline applies the regex pattern /(C(ar)*)ol/ to the fname field:

db.contacts.aggregate([
  {
    $project: {
      returnObject: {
        $regexFindAll: { input: "$fname", regex: /(C(ar)*)ol/ }
      }
    }
  }
])

The regex pattern finds a match with fname values Carol and Colleen:

{ "_id" : 1, "returnObject" : [ { "match" : "Carol", "idx" : 0, "captures" : [ "Car", "ar" ] } ] }
{ "_id" : 2, "returnObject" : [ ] }
{ "_id" : 3, "returnObject" : [ ] }
{ "_id" : 4, "returnObject" : [ { "match" : "Col", "idx" : 0, "captures" : [ "C", null ] } ] }
{ "_id" : 5, "returnObject" : [ ] }

The pattern contains the capture group (C(ar)*) which contains the nested group (ar). The elements in the captures array correspond to the two capture groups. If a matching document is not captured by a group (e.g. Colleen and the group (ar)), $regexFindAll replaces the group with a null placeholder.

Conforme o exemplo anterior, a array captures contém um elemento para cada grupo de captura (utilizando null para não capturas). Considere o seguinte exemplo que procura números de telefone com códigos de área da cidade de Nova York ao aplicar um or lógico de grupos de captura no campo phone. Cada grupo representa um código de área da cidade de Nova York:

db.contacts.aggregate([
  {
    $project: {
      nycContacts: {
        $regexFindAll: { input: "$phone", regex: /^(718).*|^(212).*|^(917).*/ }
      }
    }
  }
])

For documents which are matched by the regex pattern, the captures array includes the matching capture group and replaces any non-capturing groups with null:

{ "_id" : 1, "nycContacts" : [ { "match" : "718-555-0113", "idx" : 0, "captures" : [ "718", null, null ] } ] }
{ "_id" : 2, "nycContacts" : [ { "match" : "212-555-8832", "idx" : 0, "captures" : [ null, "212", null ] } ] }
{ "_id" : 3, "nycContacts" : [ ] }
{ "_id" : 4, "nycContacts" : [ ] }
{ "_id" : 5, "nycContacts" : [ { "match" : "917-555-4414", "idx" : 0, "captures" : [ null, null, "917" ] } ] }

$regexFindAll e suas opções

To illustrate the behavior of the $regexFindAll operator as discussed in this example, create a sample collection products with the following documents:

db.products.insertMany([
   { _id: 1, description: "Single LINE description." },
   { _id: 2, description: "First lines\nsecond line" },
   { _id: 3, description: "Many spaces before     line" },
   { _id: 4, description: "Multiple\nline descriptions" },
   { _id: 5, description: "anchors, links and hyperlinks" },
   { _id: 6, description: "métier work vocation" }
])

By default, $regexFindAll performs a case-sensitive match. For example, the following aggregation performs a case-sensitive $regexFindAll on the description field. The regex pattern /line/ does not specify any grouping:

db.products.aggregate([
   { $addFields: { returnObject: { $regexFindAll: { input: "$description", regex: /line/ } } } }
])

A operação retorna o seguinte:

{
   "_id" : 1,
   "description" : "Single LINE description.",
   "returnObject" : [ ]
}
{
   "_id" : 2,
   "description" : "First lines\nsecond line",
   "returnObject" : [ { "match" : "line", "idx" : 6, "captures" : [ ]}, { "match" : "line", "idx" : 19, "captures" : [ ] } ]
}
{
   "_id" : 3,
   "description" : "Many spaces before     line",
   "returnObject" : [ { "match" : "line", "idx" : 23, "captures" : [ ] } ]
}
{
   "_id" : 4,
   "description" : "Multiple\nline descriptions",
   "returnObject" : [ { "match" : "line", "idx" : 9, "captures" : [ ] }
] }
{
   "_id" : 5,
   "description" : "anchors, links and hyperlinks",
   "returnObject" : [ ]
}
{
   "_id" : 6,
   "description" : "métier work vocation",
   "returnObject" : [ ]
}

O seguinte padrão regex /lin(e|k)/ especifica um agrupamento (e|k) no padrão:

db.products.aggregate([
   { $addFields: { returnObject: { $regexFindAll: { input: "$description", regex: /lin(e|k)/ } } } }
])

A operação retorna o seguinte:

{
   "_id" : 1,
   "description" : "Single LINE description.",
   "returnObject": [ ]
}
{
   "_id" : 2,
   "description" : "First lines\nsecond line",
   "returnObject" : [ { "match" : "line", "idx" : 6, "captures" : [ "e" ] }, { "match" : "line", "idx" : 19, "captures" : [ "e" ] } ]
}
{
   "_id" : 3,
   "description" : "Many spaces before     line",
   "returnObject" : [ { "match" : "line", "idx" : 23, "captures" : [ "e" ] } ]
}
{
   "_id" : 4,
   "description" : "Multiple\nline descriptions",
   "returnObject" : [ { "match" : "line", "idx" : 9, "captures" : [ "e" ] } ]
}
{
   "_id" : 5,
   "description" : "anchors, links and hyperlinks",
   "returnObject" : [ { "match" : "link", "idx" : 9, "captures" : [ "k" ] }, { "match" : "link", "idx" : 24, "captures" : [ "k" ] } ]
}
{
   "_id" : 6,
   "description" : "métier work vocation",
   "returnObject" : [ ]
}

In the return option, the idx field is the code point index and not the byte index. To illustrate, consider the following example that uses the regex pattern /tier/:

db.products.aggregate([
   { $addFields: { returnObject: { $regexFindAll: { input: "$description", regex: /tier/ } } } }
])

A operação retorna o seguinte onde somente o último registro corresponde ao padrão e o idx retornado é 2 (em vez de 3 se estiver utilizando um índice de bytes)

{ "_id" : 1, "description" : "Single LINE description.", "returnObject" : [ ] }
{ "_id" : 2, "description" : "First lines\nsecond line", "returnObject" : [ ] }
{ "_id" : 3, "description" : "Many spaces before     line", "returnObject" : [ ] }
{ "_id" : 4, "description" : "Multiple\nline descriptions", "returnObject" : [ ] }
{ "_id" : 5, "description" : "anchors, links and hyperlinks", "returnObject" : [ ] }
{ "_id" : 6, "description" : "métier work vocation",
             "returnObject" : [ { "match" : "tier", "idx" : 2, "captures" : [ ] } ] }

// Specify i as part of the regex field
{ $regexFindAll: { input: "$description", regex: /line/i } }
// Specify i in the options field
{ $regexFindAll: { input: "$description", regex: /line/, options: "i" } }
{ $regexFindAll: { input: "$description", regex: "line", options: "i" } }

db.products.aggregate([
   { $addFields: { returnObject: { $regexFindAll: { input: "$description", regex: /line/i } } } }
])

{
   "_id" : 1,
   "description" : "Single LINE description.",
   "returnObject" : [ { "match" : "LINE", "idx" : 7, "captures" : [ ] } ]
}
{
   "_id" : 2,
   "description" : "First lines\nsecond line",
   "returnObject" : [ { "match" : "line", "idx" : 6, "captures" : [ ] }, { "match" : "line", "idx" : 19, "captures" : [ ] } ]
}
{
   "_id" : 3,
   "description" : "Many spaces before     line",
   "returnObject" : [ { "match" : "line", "idx" : 23, "captures" : [ ] } ]
}
{
   "_id" : 4,
   "description" : "Multiple\nline descriptions",
   "returnObject" : [ { "match" : "line", "idx" : 9, "captures" : [ ] } ]
}
{
   "_id" : 5,
   "description" : "anchors, links and hyperlinks",
   "returnObject" : [ ]
}
{ "_id" : 6, "description" : "métier work vocation", "returnObject" : [ ] }

// Specify m as part of the regex field
{ $regexFindAll: { input: "$description", regex: /line/m } }
// Specify m in the options field
{ $regexFindAll: { input: "$description", regex: /line/, options: "m" } }
{ $regexFindAll: { input: "$description", regex: "line", options: "m" } }

db.products.aggregate([
   { $addFields: { returnObject: { $regexFindAll: { input: "$description", regex: /^s/im } } } }
])

{
   "_id" : 1,
   "description" : "Single LINE description.",
   "returnObject" : [ { "match" : "S", "idx" : 0, "captures" : [ ] } ]
}
{
   "_id" : 2,
   "description" : "First lines\nsecond line",
   "returnObject" : [ { "match" : "s", "idx" : 12, "captures" : [ ] } ]
}
{
   "_id" : 3,
   "description" : "Many spaces before     line",
   "returnObject" : [ ]
}
{
   "_id" : 4,
   "description" : "Multiple\nline descriptions",
   "returnObject" : [ ]
}
{
   "_id" : 5,
   "description" : "anchors, links and hyperlinks",
   "returnObject" : [ ]
}
{ "_id" : 6, "description" : "métier work vocation", "returnObject" : [ ] }

// Specify x in the options field
{ $regexFindAll: { input: "$description", regex: /line/, options: "x" } }
{ $regexFindAll: { input: "$description", regex: "line", options: "x" } }

db.products.aggregate([
   { $addFields: { returnObject: { $regexFindAll: { input: "$description", regex: /lin(e|k) # matches line or link/, options:"x" } } } }
])

{
   "_id" : 1,
   "description" : "Single LINE description.",
   "returnObject" : [ ]
}
{
   "_id" : 2,
   "description" : "First lines\nsecond line",
   "returnObject" : [ { "match" : "line", "idx" : 6, "captures" : [ "e" ] }, { "match" : "line", "idx" : 19, "captures" : [ "e" ] } ]
}
{
   "_id" : 3,
   "description" : "Many spaces before     line",
   "returnObject" : [ { "match" : "line", "idx" : 23, "captures" : [ "e" ] } ]
}
{
   "_id" : 4,
   "description" : "Multiple\nline descriptions",
   "returnObject" : [ { "match" : "line", "idx" : 9, "captures" : [ "e" ] } ]
}
{
   "_id" : 5,
   "description" : "anchors, links and hyperlinks",
   "returnObject" : [ { "match" : "link", "idx" : 9, "captures" : [ "k" ] }, { "match" : "link", "idx" : 24, "captures" : [ "k" ] } ]
}
{ "_id" : 6, "description" : "métier work vocation", "returnObject" : [ ] }

// Specify s in the options field
{ $regexFindAll: { input: "$description", regex: /m.*line/, options: "s" } }
{ $regexFindAll: { input: "$description", regex: "m.*line", options: "s" } }

db.products.aggregate([
   { $addFields: { returnObject: { $regexFindAll: { input: "$description", regex:/m.*line/, options: "si"  } } } }
])

{
   "_id" : 1,
   "description" : "Single LINE description.",
   "returnObject" : [ ]
}
{
   "_id" : 2,
   "description" : "First lines\nsecond line",
   "returnObject" : [ ]
}
{
   "_id" : 3,
   "description" : "Many spaces before     line",
   "returnObject" : [ { "match" : "Many spaces before line", "idx" : 0, "captures" : [ ] } ]
}
{
   "_id" : 4,
   "description" : "Multiple\nline descriptions",
   "returnObject" : [ { "match" : "Multiple\nline", "idx" : 0, "captures" : [ ] } ]
}
{
   "_id" : 5,
   "description" : "anchors, links and hyperlinks",
   "returnObject" : [ ]
}
{ "_id" : 6, "description" : "métier work vocation", "returnObject" : [ ] }

Use $regexFindAll para Analisar o e-mail a partir da String

Criar uma collection de amostra feedback com os seguintes documentos:

db.feedback.insertMany([
   { "_id" : 1, comment: "Hi, I'm just reading about MongoDB -- aunt.arc.tica@example.com"  },
   { "_id" : 2, comment: "I wanted to concatenate a string" },
   { "_id" : 3, comment: "How do I convert a date to string? Contact me at either cam@mongodb.com or c.dia@mongodb.com" },
   { "_id" : 4, comment: "It's just me. I'm testing.  fred@MongoDB.com" }
])

The following aggregation uses the $regexFindAll to extract all emails from the comment field (case insensitive).

db.feedback.aggregate( [
    { $addFields: {
       "email": { $regexFindAll: { input: "$comment", regex: /[a-z0-9_.+-]+@[a-z0-9_.+-]+\.[a-z0-9_.+-]+/i } }
    } },
    { $set: { email: "$email.match"} }
] )

Primeira etapa

The stage uses the $addFields stage to add a new field email to the document. The new field is an array that contains the result of performing the $regexFindAll on the comment field:

{ "_id" : 1, "comment" : "Hi, I'm just reading about MongoDB -- aunt.arc.tica@example.com", "email" : [ { "match" : "aunt.arc.tica@example.com", "idx" : 38, "captures" : [ ] } ] }
{ "_id" : 2, "comment" : "I wanted to concatenate a string", "email" : [ ] }
{ "_id" : 3, "comment" : "How do I convert a date to string? Contact me at either cam@mongodb.com or c.dia@mongodb.com", "email" : [ { "match" : "cam@mongodb.com", "idx" : 56, "captures" : [ ] }, { "match" : "c.dia@mongodb.com", "idx" : 75, "captures" : [ ] } ] }
{ "_id" : 4, "comment" : "It's just me. I'm testing.  fred@MongoDB.com", "email" : [ { "match" : "fred@MongoDB.com", "idx" : 28, "captures" : [ ] } ] }

Segunda etapa

O estágio utiliza o estágio $set para redefinir os elementos de vetor do email para o(s) valor(es) "email.match". Se o valor atual de email for nulo, o novo valor de email será definido como nulo.

{ "_id" : 1, "comment" : "Hi, I'm just reading about MongoDB -- aunt.arc.tica@example.com", "email" : [ "aunt.arc.tica@example.com" ] }
{ "_id" : 2, "comment" : "I wanted to concatenate a string", "email" : [ ] }
{ "_id" : 3, "comment" : "How do I convert a date to string? Contact me at either cam@mongodb.com or c.dia@mongodb.com", "email" : [ "cam@mongodb.com", "c.dia@mongodb.com" ] }
{ "_id" : 4, "comment" : "It's just me. I'm testing.  fred@MongoDB.com", "email" : [ "fred@MongoDB.com" ] }

Usar agrupamentos capturados para analisar o nome de usuário

Criar uma collection de amostra feedback com os seguintes documentos:

db.feedback.insertMany([
   { "_id" : 1, comment: "Hi, I'm just reading about MongoDB -- aunt.arc.tica@example.com"  },
   { "_id" : 2, comment: "I wanted to concatenate a string" },
   { "_id" : 3, comment: "How do I convert a date to string? Contact me at either cam@mongodb.com or c.dia@mongodb.com" },
   { "_id" : 4, comment: "It's just me. I'm testing.  fred@MongoDB.com" }
])

To reply to the feedback, assume you want to parse the local-part of the email address to use as the name in the greetings. Using the captured field returned in the $regexFindAll results, you can parse out the local part of each email address:

db.feedback.aggregate( [
    { $addFields: {
       "names": { $regexFindAll: { input: "$comment", regex: /([a-z0-9_.+-]+)@[a-z0-9_.+-]+\.[a-z0-9_.+-]+/i } },
    } },
    { $set: { names: { $reduce: { input:  "$names.captures", initialValue: [ ], in: { $concatArrays: [ "$$value", "$$this" ] } } } } }
] )

Primeira etapa

The stage uses the $addFields stage to add a new field names to the document. The new field contains the result of performing the $regexFindAll on the comment field:

{
   "_id" : 1,
   "comment" : "Hi, I'm just reading about MongoDB -- aunt.arc.tica@example.com",
   "names" : [ { "match" : "aunt.arc.tica@example.com", "idx" : 38, "captures" : [ "aunt.arc.tica" ] } ]
}
{ "_id" : 2, "comment" : "I wanted to concatenate a string", "names" : [ ] }
{
   "_id" : 3,
   "comment" : "How do I convert a date to string? Contact me at either cam@mongodb.com or c.dia@mongodb.com",
   "names" : [
      { "match" : "cam@mongodb.com", "idx" : 56, "captures" : [ "cam" ] },
      { "match" : "c.dia@mongodb.com", "idx" : 75, "captures" : [ "c.dia" ] }
    ]
}
{
   "_id" : 4,
   "comment" : "It's just me. I'm testing.  fred@MongoDB.com",
   "names" : [ { "match" : "fred@MongoDB.com", "idx" : 28, "captures" : [ "fred" ] } ]
}

Segunda etapa

O estágio usa o estágio $set com o operador $reduce para redefinir names para uma array que contém os elementos "$names.captures".

{
   "_id" : 1,
   "comment" : "Hi, I'm just reading about MongoDB -- aunt.arc.tica@example.com",
   "names" : [ "aunt.arc.tica" ]
}
{ "_id" : 2, "comment" : "I wanted to concatenate a string", "names" : [ ] }
{
   "_id" : 3,
   "comment" : "How do I convert a date to string? Contact me at either cam@mongodb.com or c.dia@mongodb.com",
   "names" : [ "cam", "c.dia" ]
}
{
   "_id" : 4,
   "comment" : "It's just me. I'm testing.  fred@MongoDB.com",
   "names" : [ "fred" ]
}