Class: Cassava::StatementBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/cassava/client.rb

Constant Summary collapse

CLAUSE_ORDERING = 
{
 :main => 0,
 :from => 1,
 :where => 2,
 :order => 3,
 :limit => 4,
 :allow_filtering => 5
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(executor, clauses = {}) ⇒ StatementBuilder

Returns a new instance of StatementBuilder.



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# File 'lib/cassava/client.rb', line 74

def initialize(executor, clauses = {})
  @executor = executor
  @table = table
  @clauses = clauses
end

Instance Attribute Details

#clauses ⇒ Object (readonly)

Returns the value of attribute clauses.



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# File 'lib/cassava/client.rb', line 63

def clauses
  @clauses
end

#executor ⇒ Object (readonly)

Returns the value of attribute executor.



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# File 'lib/cassava/client.rb', line 63

def executor
  @executor
end

#table ⇒ Object (readonly)

Returns the value of attribute table.



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# File 'lib/cassava/client.rb', line 63

def table
  @table
end

Instance Method Details

#allow_filtering ⇒ StatementBuilder

Allow filtering for this query

Returns:



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# File 'lib/cassava/client.rb', line 123

def allow_filtering
  add_clause('ALLOW FILTERING', :allow_filtering)
end

#count ⇒ StatementBuilder

Return the count of objects rather than the objects themselves

Returns:



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# File 'lib/cassava/client.rb', line 142

def count
  add_clause(clauses[:main].count, :main)
end

#delete(table, columns = nil) ⇒ StatementBuilder

Parameters:

  • table (Symbol) —

    table to delete data from

  • columns (Array<Symbol>) (defaults to: nil) —

    Columns to delete – defaults to all.

Returns:



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# File 'lib/cassava/client.rb', line 104

def delete(table, columns = nil)
  add_clause(DeleteClause.new(table, columns), :main)
end

#execute(opts = {}) ⇒ Object

Execute the statement synchronously

Parameters:

  • opts (Hash) (defaults to: {}) —

    options accepted by Cassandra::Session



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# File 'lib/cassava/client.rb', line 82

def execute(opts = {})
  options = opts.dup.merge(:arguments => prepared_arguments)
  executor.execute(prepared_statement, options)
end

#execute_async(opts = {}) ⇒ Object

Execute the statement asynchronously

Parameters:

  • opts (Hash) (defaults to: {}) —

    options accepted by Cassandra::Session



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# File 'lib/cassava/client.rb', line 89

def execute_async(opts = {})
  options = opts.dup.merge(:arguments => prepared_arguments)
  executor.execute_async(prepared_statement, options)
end

#limit(n) ⇒ StatementBuilder

Parameters:

  • n (Integer) —

    maximum number of results to return

Returns:



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# File 'lib/cassava/client.rb', line 136

def limit(n)
  add_clause("LIMIT #{n.to_i}", :limit)
end

#order(clustering_column, direction = :asc) ⇒ StatementBuilder

Parameters:

  • clustering_column (Symbol) —

    clustering_column to order by

  • direction (:asc|:desc) (defaults to: :asc) —

    the direction to order by, defaults to :asc

Returns:



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# File 'lib/cassava/client.rb', line 130

def order(clustering_column, direction = :asc)
  add_clause("ORDER BY #{clustering_column.to_s} #{direction.to_s}", :order)
end

#select(table, columns = nil) ⇒ StatementBuilder

Parameters:

  • table (Symbol) —

    table to select data from

  • columns (Array<Symbol>) (defaults to: nil) —

    Columns to select – defaults to all.

Returns:



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# File 'lib/cassava/client.rb', line 97

def select(table, columns = nil)
  add_clause(SelectClause.new(table, columns), :main)
end

#statement ⇒ String

Returns the CQL statement that this StatementBuilder represents.

Returns:

  • (String) —

    the CQL statement that this StatementBuilder represents



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# File 'lib/cassava/client.rb', line 147

def statement
  clauses.sort_by { |s| CLAUSE_ORDERING[s[0]] }.map { |s| s[1] }.join(' ')
end

#where(*args) ⇒ StatementBuilder

Condition the query based on a condition Provide either a String and a list of arguments, or a hash.

Examples:

statement.where('id = ? and field > ?', 1, 'a')
statement.where(:id => 1, :field => 'x')

Parameters:

  • args (Array) —

    arguments representing the where condition

Returns:



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# File 'lib/cassava/client.rb', line 116

def where(*args)
  clause = clauses[:where] || WhereClause.new([], [])
  add_clause(clause.where(*args), :where)
end