সীমা

বর্ণনা

পাইপলাইন দ্বারা ফেরত আসা নথির সংখ্যা সীমিত করে।

উদাহরণ

Web 

const pipeline = db.pipeline()
  // Step 1: Start a query with collection scope
  .collection("cities")
  // Step 2: Filter the collection
  .where(field("population").greaterThan(100000))
  // Step 3: Sort the remaining documents
  .sort(field("name").ascending())
  // Step 4: Return the top 10. Note applying the limit earlier in the
  // pipeline would have unintentional results.
  .limit(10);
সুইফট 
let pipeline = db.pipeline()
  // Step 1: Start a query with collection scope
  .collection("cities")
  // Step 2: Filter the collection
  .where(Field("population").greaterThan(100000))
  // Step 3: Sort the remaining documents
  .sort([Field("name").ascending()])
  // Step 4: Return the top 10. Note applying the limit earlier in the pipeline would have
  // unintentional results.
  .limit(10)

Kotlin 

val pipeline = db.pipeline()
    // Step 1: Start a query with collection scope
    .collection("cities")
    // Step 2: Filter the collection
    .where(field("population").greaterThan(100000))
    // Step 3: Sort the remaining documents
    .sort(field("name").ascending())
    // Step 4: Return the top 10. Note applying the limit earlier in the pipeline would have
    // unintentional results.
    .limit(10)

Java 

Pipeline pipeline = db.pipeline()
    // Step 1: Start a query with collection scope
    .collection("cities")
    // Step 2: Filter the collection
    .where(field("population").greaterThan(100000))
    // Step 3: Sort the remaining documents
    .sort(field("name").ascending())
    // Step 4: Return the top 10. Note applying the limit earlier in the pipeline would have
    // unintentional results.
    .limit(10);
পাইথন 
from google.cloud.firestore_v1.pipeline_expressions import Field

pipeline = (
    client.pipeline()
    .collection("cities")
    .where(Field.of("population").greater_than(100_000))
    .sort(Field.of("name").ascending())
    .limit(10)
)
জাভা 
Pipeline pipeline =
    firestore
        .pipeline()
        .collection("cities")
        .where(field("population").greaterThan(100_000))
        .sort(ascending(field("name")))
        .limit(10);
যান 
pipeline := client.Pipeline().
	Collection("cities").
	Where(firestore.FieldOf("population").GreaterThan(100000)).
	Sort(firestore.Orders(firestore.Ascending(firestore.FieldOf("name")))).
	Limit(10)

আচরণ

limit(...) পর্যায়টি শুধুমাত্র প্রথম N ডকুমেন্ট ফেরত দেবে। limit-এর আগে sort(...) পর্যায় ব্যবহার না করা হলে, ডকুমেন্টগুলো যে ক্রমে ফেরত আসে তা অস্থিতিশীল থাকে এবং বারবার চালালে ভিন্ন ভিন্ন ফলাফল আসতে পারে।