Class: NativeQuery::Join

Inherits:
Object
  • Object
show all
Defined in:
lib/native-query/join.rb

Overview

Represents join request.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(original, table) ⇒ Join

Constructor.



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# File 'lib/native-query/join.rb', line 72

def initialize(original, table)
    @table = table
    @original = original
    @fields = [ ]
    @where = [ ]
    @joins = [ ]
    @type = :direct
    
    @indirect_source = original
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args, &block) ⇒ Object

Calls mapping to joins specification. Call name is name of the target table.

Block works by the same way as query, but for join. But intra-join calls doesn’t work because it returns Query too.



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# File 'lib/native-query/join.rb', line 188

def method_missing(sym, *args, &block)
    join = self.class::new(@table, sym)

    if args and not args.empty?
        join.fields(*args)
    end

    join.instance_eval(&block)
    @joins << join
    
    return self
end

Instance Attribute Details

#joins ⇒ Object (readonly)

Returns the value of attribute joins.



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# File 'lib/native-query/join.rb', line 38

def joins
  @joins
end

Instance Method Details

#backward(*args) ⇒ Object

Indicates backward joining.



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# File 'lib/native-query/join.rb', line 151

def backward(*args)
    [:backward, args]
end

#build ⇒ Object

Builds ON join string.



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# File 'lib/native-query/join.rb', line 159

def build
    result = nil
    
    case @type
        when :indirect
            result = __indirect
        when :direct
            result = __direct
    end
    
    return result
end

#direct(*args) ⇒ Object

Indicates direct joining. (1:M)



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# File 'lib/native-query/join.rb', line 136

def direct(*args)
    @type = :direct
    if args.first.array? and (args.first.first == :backward) and (args.first.second.array?)
        @direct = args.first
    else
        @direct = args
    end
    
    return self
end

#fields(*args) ⇒ Object

Sets hash for select from joined table. Without arguments returns fields list.



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# File 'lib/native-query/join.rb', line 88

def fields(*args)
    if args.empty?
        result = { }
        @fields.each do |i|
            if not i.kind_of? Hash
                i = {i => i}
            end
            
            i.each_pair do |from, to|
                result[__fix_field(from)] = @table.to_s << "_" << to.to_s
            end
        end
        
        return result
    else
        @fields += args
        return self
    end
end

#indirect(*args) ⇒ Object

Indicates indirect joining. (M:N)



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# File 'lib/native-query/join.rb', line 121

def indirect(*args)
    @type = :indirect
    if args.first.array? and (args.first.first == :backward) and (args.first.second.array?)
        @indirect = args.first
    else
        @indirect = args
    end
    
    return self
end

#where(*args) ⇒ Object

Selects where conditions to load.



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# File 'lib/native-query/join.rb', line 112

def where(*args)
    @where << args
    return self
end

#wheres ⇒ Object

Return wheres.



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# File 'lib/native-query/join.rb', line 176

def wheres
    self._fix_where
end