class PgORM::Collection(T)

• PgORM::Collection(T)
• Reference
• Object

Overview

Build Database Queries.

A Collection is immutable: all methods will return a copy of the previous Collection with the added constraint(s). For example:

users = User.select(:id, :name).where(group_id: 2)

Termination methods such as #find_by, or #take will explicitly execute a SQL request against the database and load one record.

first_user = users.order(:name).take
# => SELECT "id", "name"
#    FROM "users"
#    WHERE "group_id" = 2
#    ORDER BY "name" ASC
#    LIMIT 1;

Termination methods such as #to_a or #each will execute a SQL request then cache loaded records into the Collection, so further accesses won't re-execute the SQL request. Some methods such as #first or #size will leverage this cache when it's available.

users.to_a
# => SELECT "id", "name" FROM "users" WHERE "group_id" = 2;

When specifying column names you should always use a Symbol, so they'll be properly quoted for the database server. In many cases you can specify raw SQL statements using a String. For example:

users = User.where("LENGTH(name) > $0", 10)
# => SELECT * FROM "users" WHERE LENGTH(name) > 10;

users = User.order("LENGTH(name) DESC")
# => SELECT * FROM "users" ORDER BY LENGTH(name) DESC;

count = User.count("LENGTH(name)", distinct: true)
# => SELECT COUNT(DISTINCT LENGTH(name)) FROM "users";

Included Modules

• Enumerable(T)
• PgORM::Pagination(T)
• PgORM::Query::Cache(T)
• PgORM::Query::Methods(T)

Defined in:

Instance Method Summary

• #explain : String

  Returns the query execution plan (useful for optimization) Note: This only works for SELECT queries (Collection is for queries, not mutations)

• #in_groups_of(size : Int, filled_up_with : U = nil, reuse = false, &) forall U

  Yields a block with the chunks in the given size.

• #search(query : String, columns : Array(String), config : String = "english") : self

  Convenience method for full-text search

• #search(query : String, *columns : Symbol, config : String = "english") : self

  Overload: Accepts Symbol columns

• #search(query : String, *columns : String, config : String = "english") : self

  Overload: Accepts String columns

• #search_phrase(phrase : String, columns : Array(String), config : String = "english") : self

  Convenience method for phrase search

• #search_phrase(phrase : String, *columns : Symbol, config : String = "english") : self

  Overload: Accepts Symbol columns

• #search_phrase(phrase : String, *columns : String, config : String = "english") : self

  Overload: Accepts String columns

• #search_plain(text : String, columns : Array(String), config : String = "english") : self

  Convenience method for plain text search

• #search_plain(text : String, *columns : Symbol, config : String = "english") : self

  Overload: Accepts Symbol columns

• #search_plain(text : String, *columns : String, config : String = "english") : self

  Overload: Accepts String columns

• #search_prefix(prefix : String, columns : Array(String), config : String = "english") : self

  Convenience method for prefix search

• #search_prefix(prefix : String, *columns : Symbol, config : String = "english") : self

  Overload: Accepts Symbol columns

• #search_prefix(prefix : String, *columns : String, config : String = "english") : self

  Overload: Accepts String columns

• #search_proximity(word1 : String, word2 : String, distance : Int32, columns : Array(String), config : String = "english") : self

  Convenience method for proximity search

• #search_proximity(word1 : String, word2 : String, distance : Int32, *columns : Symbol, config : String = "english") : self

  Overload: Accepts Symbol columns

• #search_proximity(word1 : String, word2 : String, distance : Int32, *columns : String, config : String = "english") : self

  Overload: Accepts String columns

• #search_ranked(query : String, columns : Array(String), config : String = "english", rank_normalization : Int32 | Nil = nil, rank_function : FullTextSearch::RankFunction = FullTextSearch::RankFunction::Rank) : self

  Convenience method for ranked full-text search

• #search_ranked(query : String, *columns : Symbol, config : String = "english", rank_normalization : Int32 | Nil = nil, rank_function : FullTextSearch::RankFunction = FullTextSearch::RankFunction::Rank) : self

  Overload: Accepts Symbol columns

• #search_ranked(query : String, *columns : String, config : String = "english", rank_normalization : Int32 | Nil = nil, rank_function : FullTextSearch::RankFunction = FullTextSearch::RankFunction::Rank) : self

  Overload: Accepts String columns

• #search_ranked_weighted(query : String, weighted_columns : Hash(String, FullTextSearch::Weight), config : String = "english", rank_normalization : Int32 | Nil = nil, rank_function : FullTextSearch::RankFunction = FullTextSearch::RankFunction::Rank) : self

  Convenience method for ranked weighted search

• #search_ranked_weighted(query : String, weighted_columns : Hash(Symbol, FullTextSearch::Weight), config : String = "english", rank_normalization : Int32 | Nil = nil, rank_function : FullTextSearch::RankFunction = FullTextSearch::RankFunction::Rank) : self

  Overload: Accepts Symbol keys

• #search_vector(query : String, vector_column : String, config : String = "english") : self

  Convenience method for searching pre-computed tsvector column

• #search_vector(query : String, vector_column : Symbol, config : String = "english") : self

  Overload: Accepts Symbol for vector column

• #search_vector_plain(text : String, vector_column : String, config : String = "english") : self

  Convenience method for searching pre-computed tsvector column with plain text

• #search_vector_plain(text : String, vector_column : Symbol, config : String = "english") : self

  Overload: Accepts Symbol for vector column

• #search_vector_ranked(query : String, vector_column : String, config : String = "english", rank_normalization : Int32 | Nil = nil, rank_function : FullTextSearch::RankFunction = FullTextSearch::RankFunction::Rank) : self

  Convenience method for searching pre-computed tsvector column with ranking

• #search_vector_ranked(query : String, vector_column : Symbol, config : String = "english", rank_normalization : Int32 | Nil = nil, rank_function : FullTextSearch::RankFunction = FullTextSearch::RankFunction::Rank) : self

  Overload: Accepts Symbol for vector column

• #search_weighted(query : String, weighted_columns : Hash(String, FullTextSearch::Weight), config : String = "english") : self

  Convenience method for weighted full-text search

• #search_weighted(query : String, weighted_columns : Hash(Symbol, FullTextSearch::Weight), config : String = "english") : self

  Overload: Accepts Symbol keys

Instance Method Detail

[1, 2, 4].in_groups_of(2, 0) { |e| p e.sum }
# => 3
# => 4