Class: Checkpoint::DB::Params
- Inherits:
-
Object
- Object
- Checkpoint::DB::Params
- Defined in:
- lib/checkpoint/db/params.rb
Overview
A helper for building placeholder variable names from items in a list and providing a corresponding hash of values. A prefix with some mnemonic corresponding to the column is recommended. For example, if the column is ‘agent_token`, using the prefix `at` will yield `$at_0`, `$at_1`, etc. for an IN clause.
Instance Attribute Summary collapse
-
#items ⇒ Object
readonly
Returns the value of attribute items.
-
#prefix ⇒ Object
readonly
Returns the value of attribute prefix.
Instance Method Summary collapse
-
#initialize(items, prefix) ⇒ Params
constructor
A new instance of Params.
- #placeholders ⇒ Object
- #values ⇒ Object
Constructor Details
#initialize(items, prefix) ⇒ Params
Returns a new instance of Params.
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# File 'lib/checkpoint/db/params.rb', line 13 def initialize(items, prefix) @items = [items].flatten @prefix = prefix end |
Instance Attribute Details
#items ⇒ Object (readonly)
Returns the value of attribute items.
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# File 'lib/checkpoint/db/params.rb', line 11 def items @items end |
#prefix ⇒ Object (readonly)
Returns the value of attribute prefix.
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# File 'lib/checkpoint/db/params.rb', line 11 def prefix @prefix end |
Instance Method Details
#placeholders ⇒ Object
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# File 'lib/checkpoint/db/params.rb', line 18 def placeholders 0.upto(items.size - 1).map do |i| :"$#{prefix}_#{i}" end end |
#values ⇒ Object
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# File 'lib/checkpoint/db/params.rb', line 24 def values items.map.with_index do |item, i| value = if item.respond_to?(:sql_value) item.sql_value else item.to_s end [:"#{prefix}_#{i}", value] end end |