Class: I_Dig_Sql

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/i_dig_sql.rb

Defined Under Namespace

Classes: H

Constant Summary collapse

HAS_VAR = 
/(\{\{|\<\<)[^\}\>]+(\}\}|\>\>)/
Duplicate = 
Class.new RuntimeError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ I_Dig_Sql

Returns a new instance of I_Dig_Sql.



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# File 'lib/i_dig_sql.rb', line 39

def initialize *args
  @digs = args.select { |a|
    a.is_a? I_Dig_Sql
  }

  @sqls = H.new
  @vars = H.new

  @sqls.merge_these *(@digs.map(&:sqls))
  @vars.merge_these *(@digs.map(&:vars))

  @string = args.select { |s| s.is_a? String }.join("\n")
end

Instance Attribute Details

#sqls ⇒ Object (readonly)

class H



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# File 'lib/i_dig_sql.rb', line 38

def sqls
  @sqls
end

#vars ⇒ Object (readonly)

class H



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# File 'lib/i_dig_sql.rb', line 38

def vars
  @vars
end

Instance Method Details

#<<(str) ⇒ Object 



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# File 'lib/i_dig_sql.rb', line 69

def << str
  @string << (
    if @string.empty?
      str
    else
      "\n" << str
    end
  )
end

#[](name) ⇒ Object 



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# File 'lib/i_dig_sql.rb', line 53

def [] name
  @sqls[name]
end

#[]=(name, val) ⇒ Object 



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# File 'lib/i_dig_sql.rb', line 57

def []= name, val
  @sqls[name] = val
end

#each ⇒ Object 



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# File 'lib/i_dig_sql.rb', line 61

def each
  if block_given?
    @sqls.each { |k, v| yield k, v }
  else
    @sqls.each
  end
end

#to_pair ⇒ Object 



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# File 'lib/i_dig_sql.rb', line 79

def to_pair
  [to_sql, vars]
end

#to_sql ⇒ Object 



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# File 'lib/i_dig_sql.rb', line 83

def to_sql
  s    = @string.dup
  ctes = []

  while s[HAS_VAR]
    s.gsub!(/\{\{\s?([a-zA-Z0-9\_]+)\s?\}\}/) do |match|
      key = $1.to_sym
      ctes << key
      key
    end

    s.gsub!(/\<\<\s?([a-zA-Z0-9\_\-\ \*]+)\s?\>\>/) do |match|
      tokens = $1.split
      key    = tokens.pop.to_sym
      field  = tokens.empty? ? nil : tokens.join(' ')

      case
      when field
        ctes << key
        "SELECT #{field} FROM #{key}"
      else
        self[key]
      end
    end
  end

  return s if ctes.empty?

  %^
    WITH
    #{ctes.uniq.map { |k| "#{k} AS (
      #{self[k]}
    )" }.join "
    ,
    "}
    #{s}
  ^
end