Class: ConceptQL::TempTable

Inherits:
Object
  • Object
show all
Defined in:
lib/conceptql/utils/temp_table.rb

Overview

TempTable coordinates the creation of any temporary tables a statement might need.

Currently, temp tables are used to share a set of results when a Recall operator is present in a statement.

It also provides an API to generate the SQL that Sequel would use to create and populate the temp table

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(operator, db) ⇒ TempTable 



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# File 'lib/conceptql/utils/temp_table.rb', line 14

def initialize(operator, db)
  @operator = operator
  fake_it!(db)
end

Instance Attribute Details

#operator ⇒ Object (readonly)

Returns the value of attribute operator.



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# File 'lib/conceptql/utils/temp_table.rb', line 13

def operator
  @operator
end

Instance Method Details

#build(db) ⇒ Object 



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# File 'lib/conceptql/utils/temp_table.rb', line 19

def build(db)
  @built ||= build_it(db)
end

#from(db) ⇒ Object 



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# File 'lib/conceptql/utils/temp_table.rb', line 30

def from(db)
  db[table_name]
end

#sql(db) ⇒ Object 



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# File 'lib/conceptql/utils/temp_table.rb', line 23

def sql(db)
  # Sequel doesn't (currently) provide an API for getting the SQL for the
  # creation of tables, so we're calling one of the private methods
  sql = db[db.send(:create_table_as_sql, table_name, operator.evaluate(db), temp: true)].sql
  ["-- #{operator.label}", sql].join("\n")
end