Class: Array
- Defined in:
- lib/sequel/extensions/core_extensions.rb,
lib/sequel/extensions/pg_array.rb
Overview
Sequel extends Array
to add methods to implement the SQL DSL. Most of these methods require that the array not be empty and that it must consist solely of other arrays that have exactly two elements.
Direct Known Subclasses
Instance Method Summary collapse
-
#case(*args) ⇒ Object
Return a
Sequel::SQL::CaseExpression
with this array as the conditions and the given default value and expression. -
#pg_array(type = nil) ⇒ Object
Return a PGArray proxy to the receiver, using a specific database type if given.
-
#sql_expr ⇒ Object
Return a
Sequel::SQL::BooleanExpression
created from this array, matching all of the conditions. -
#sql_negate ⇒ Object
Return a
Sequel::SQL::BooleanExpression
created from this array, matching none of the conditions. -
#sql_or ⇒ Object
Return a
Sequel::SQL::BooleanExpression
created from this array, matching any of the conditions. -
#sql_string_join(joiner = nil) ⇒ Object
Return a
Sequel::SQL::StringExpression
representing an SQL string made up of the concatenation of this array’s elements. -
#sql_value_list ⇒ Object
(also: #sql_array)
Return a
Sequel::SQL::ValueList
created from this array. -
#~ ⇒ Object
Return a
Sequel::SQL::BooleanExpression
created from this array, not matching all of the conditions.
Instance Method Details
#case(*args) ⇒ Object
Return a Sequel::SQL::CaseExpression
with this array as the conditions and the given default value and expression.
[[{: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
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# File 'lib/sequel/extensions/core_extensions.rb', line 29 def case(*args) ::Sequel::SQL::CaseExpression.new(self, *args) end |
#pg_array(type = nil) ⇒ Object
Return a PGArray proxy to the receiver, using a specific database type if given. This is mostly useful as a short cut for creating PGArray objects that didn’t come from the database.
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# File 'lib/sequel/extensions/pg_array.rb', line 457 def pg_array(type=nil) Sequel::Postgres::PGArray.new(self, type) end |
#sql_expr ⇒ Object
Return a Sequel::SQL::BooleanExpression
created from this array, matching all of the conditions. Rarely do you need to call this explicitly, as Sequel generally assumes that arrays of two element arrays specify this type of condition. One case where it can be necessary to use this is if you are using the object as a value in a filter hash and want to use the = operator instead of the IN operator (which is used by default for arrays of two element arrays).
[[:a, true]].sql_expr # SQL: a IS TRUE
[[:a, 1], [:b, [2, 3]]].sql_expr # SQL: a = 1 AND b IN (2, 3)
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# File 'lib/sequel/extensions/core_extensions.rb', line 58 def sql_expr Sequel.expr(self) end |
#sql_negate ⇒ Object
Return a Sequel::SQL::BooleanExpression
created from this array, 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)
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# File 'lib/sequel/extensions/core_extensions.rb', line 67 def sql_negate Sequel.negate(self) end |
#sql_or ⇒ Object
Return a Sequel::SQL::BooleanExpression
created from this array, 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)
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# File 'lib/sequel/extensions/core_extensions.rb', line 76 def sql_or Sequel.or(self) end |
#sql_string_join(joiner = nil) ⇒ Object
Return a Sequel::SQL::StringExpression
representing an SQL string made up of the concatenation of this array’s elements. If an argument is passed it is used in between each element of the array in the SQL concatenation.
[:a].sql_string_join # SQL: a
[:a, :b].sql_string_join # SQL: a || b
[:a, 'b'].sql_string_join # SQL: a || 'b'
['a', :b].sql_string_join(' ') # SQL: 'a' || ' ' || b
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# File 'lib/sequel/extensions/core_extensions.rb', line 89 def sql_string_join(joiner=nil) Sequel.join(self, joiner) end |
#sql_value_list ⇒ Object Also known as: sql_array
Return a Sequel::SQL::ValueList
created from this array. Used if this array contains all two element arrays and you want it treated as an SQL value list (IN predicate) instead of as a conditions specifier (similar to a hash). This is not necessary if you are using this array as a value in a filter, but may be necessary if you are using it as a value with placeholder SQL:
DB[:a].filter([:a, :b]=>[[1, 2], [3, 4]]) # SQL: (a, b) IN ((1, 2), (3, 4))
DB[:a].filter('(a, b) IN ?', [[1, 2], [3, 4]]) # SQL: (a, b) IN ((1 = 2) AND (3 = 4))
DB[:a].filter('(a, b) IN ?', [[1, 2], [3, 4]].sql_value_list) # SQL: (a, b) IN ((1, 2), (3, 4))
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# File 'lib/sequel/extensions/core_extensions.rb', line 42 def sql_value_list ::Sequel::SQL::ValueList.new(self) end |