Class: Hash

Inherits:
Object show all
Defined in:
lib/sequel/core_sql.rb

Overview

Sequel extends Hash to add methods to implement the SQL DSL.

Instance Method Summary collapse

Instance Method Details

#&(ce) ⇒ Object

Return a Sequel::SQL::BooleanExpression created from this hash, matching all of the conditions in this hash and the condition specified by the given argument.

{:a=>1} & :b # SQL: a = 1 AND b
{:a=>true} & ~:b # SQL: a IS TRUE AND NOT b



120
121
122
 
# File 'lib/sequel/core_sql.rb', line 120

def &(ce)
  ::Sequel::SQL::BooleanExpression.new(:AND, self, ce)
end

#case(*args) ⇒ Object

Return a Sequel::SQL::CaseExpression with this hash as the conditions and the given default value. Note that the order of the conditions will be arbitrary on ruby 1.8, so all conditions should be orthogonal.

{{:a=>[2,3]}=>1}.case(0) # SQL: CASE WHEN a IN (2, 3) THEN 1 ELSE 0 END
{:a=>1, :b=>2}.case(:d, :c) # SQL: CASE c WHEN a THEN 1 WHEN b THEN 2 ELSE d END
                              #  or: CASE c WHEN b THEN 2 WHEN a THEN 1 ELSE d END



150
151
152
 
# File 'lib/sequel/core_sql.rb', line 150

def case(*args)
  ::Sequel::SQL::CaseExpression.new(to_a, *args)
end

#sql_expr ⇒ Object

Return a Sequel::SQL::BooleanExpression created from this hash, matching all of the conditions. Rarely do you need to call this explicitly, as Sequel generally assumes that hashes specify this type of condition.

{:a=>true}.sql_expr # SQL: a IS TRUE
{:a=>1, :b=>[2, 3]}.sql_expr # SQL: a = 1 AND b IN (2, 3)



160
161
162
 
# File 'lib/sequel/core_sql.rb', line 160

def sql_expr
  ::Sequel::SQL::BooleanExpression.from_value_pairs(self)
end

#sql_negate ⇒ Object

Return a Sequel::SQL::BooleanExpression created from this hash, matching none of the conditions.

{:a=>true}.sql_negate # SQL: a IS NOT TRUE
{:a=>1, :b=>[2, 3]}.sql_negate # SQL: a != 1 AND b NOT IN (2, 3)



169
170
171
 
# File 'lib/sequel/core_sql.rb', line 169

def sql_negate
  ::Sequel::SQL::BooleanExpression.from_value_pairs(self, :AND, true)
end

#sql_or ⇒ Object

Return a Sequel::SQL::BooleanExpression created from this hash, matching any of the conditions.

{:a=>true}.sql_or # SQL: a IS TRUE
{:a=>1, :b=>[2, 3]}.sql_or # SQL: a = 1 OR b IN (2, 3)



178
179
180
 
# File 'lib/sequel/core_sql.rb', line 178

def sql_or
  ::Sequel::SQL::BooleanExpression.from_value_pairs(self, :OR)
end

#|(ce) ⇒ Object

Return a Sequel::SQL::BooleanExpression created from this hash, matching all of the conditions in this hash or the condition specified by the given argument.

{:a=>1} | :b # SQL: a = 1 OR b
{:a=>true} | ~:b # SQL: a IS TRUE OR NOT b



130
131
132
 
# File 'lib/sequel/core_sql.rb', line 130

def |(ce)
  ::Sequel::SQL::BooleanExpression.new(:OR, self, ce)
end

#~ ⇒ Object

Return a Sequel::SQL::BooleanExpression created from this hash, not matching all of the conditions.

~{:a=>true} # SQL: a IS NOT TRUE
~{:a=>1, :b=>[2, 3]} # SQL: a != 1 OR b NOT IN (2, 3)



139
140
141
 
# File 'lib/sequel/core_sql.rb', line 139

def ~
  ::Sequel::SQL::BooleanExpression.from_value_pairs(self, :OR, true)
end