Class: Gitlab::Database::QueryAnalyzers::PreventSetOperatorMismatch::Targets

Inherits:
Object
  • Object
show all
Defined in:
lib/gitlab/database/query_analyzers/prevent_set_operator_mismatch/targets.rb

Class Method Summary collapse

Class Method Details

.a_star?(target) ⇒ Boolean

True when ‘SELECT *`

Returns:

  • (Boolean) 


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# File 'lib/gitlab/database/query_analyzers/prevent_set_operator_mismatch/targets.rb', line 32

def a_star?(target)
  Node.locate_descendant(target, :a_star)
end

.null?(target) ⇒ Boolean

Null targets are used to produce “polymorphic” query result sets that can be aggregated through a UNION without having to worry about mismatched columns.

A null target would be something like: SELECT NULL::namespaces FROM namespaces

Returns:

  • (Boolean) 


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# File 'lib/gitlab/database/query_analyzers/prevent_set_operator_mismatch/targets.rb', line 41

def null?(target)
  target&.val&.type_cast&.arg&.a_const&.isnull
end

.reference_names(target, select_stmt) ⇒ Object

Return the reference names used by the given target.

For example: ‘SELECT users.id` would return [’users’] ‘SELECT * FROM users, namespaces` would return [’users’, ‘namespaces’]



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# File 'lib/gitlab/database/query_analyzers/prevent_set_operator_mismatch/targets.rb', line 16

def reference_names(target, select_stmt)
  # Parse all targets to determine what is referenced.
  fields = fields(target)
  case fields.count
  when 0
    literal_ref_names(target, select_stmt)
  when 1
    unqualified_ref_names(fields, select_stmt)
  else
    # The target is qualified such as SELECT reference.id
    field_ref = fields[fields.count - 2]
    [field_ref.string.sval]
  end
end