Class: I_Dig_Sql

Inherits:
Object
  • Object
show all
Defined in:
lib/i_dig_sql.rb,
lib/i_dig_sql/H.rb,
lib/i_dig_sql/string.rb

Defined Under Namespace

Classes: H

Constant Summary collapse

Box = 
Boxomojo.new(
  :SELECT,
  :FROM, :LEFT, :RIGHT, :INNER,
  :AS, :ON,
  :GROUP_BY, :ORDER_BY
)
HAS_VAR = 
/(\{\{)[^\}\>]+(\}\})/
SELECT_FROM_REG = 
/SELECT.+FROM.+/
COMMAS_OR_COLONS = 
/(\,|\:)+/
ALL_UNDERSCORE = 
/\A[_]+\Z/
NOTHING = 
"".freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(str) ⇒ I_Dig_Sql

Returns a new instance of I_Dig_Sql.



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# File 'lib/i_dig_sql.rb', line 141

def initialize
  @stack = []
  @sqls  = H.new
  @vars  = H.new
end

Instance Attribute Details

#sqls ⇒ Object (readonly)

class self ===



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# File 'lib/i_dig_sql.rb', line 140

def sqls
  @sqls
end

#vars ⇒ Object (readonly)

class self ===



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# File 'lib/i_dig_sql.rb', line 140

def vars
  @vars
end

Class Method Details

.box_to_string(arr) ⇒ Object 



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# File 'lib/i_dig_sql.rb', line 23

def box_to_string arr
  h = {:SELECT=>[], :FROM=>[], :GROUP_BY=>[], :ORDER_BY=>[]}
  table_name_stack = []
  arr.each { |raw|
    name, args, blok = raw

    case name
    when :SELECT
      h[:SELECT] << args.join(' AS ')

    when :FROM, :LEFT, :RIGHT, :INNER
      table_name_stack.push args.last
      str = if name == :FROM
              args.join(' ')
            else
              "#{name} JOIN #{args.join ' '}"
            end

      table_name = args.last

      if blok
        on = []
        blok.each { |raw|
          args = raw.dup
          name = args.shift
          blok = args.pop
          case name
          when :ON
            on << args

          when :SELECT
            h[:SELECT] << "#{table_name}.#{args.join ' AS '}"

          else
            fail ArgumentError, "Unknown name: #{name.inspect}"
          end
        }

        ( str << "\nON " << on.join(' AND ') ) unless on.empty?
      end

      str.gsub!(/\b([_]+)(?=\.)/) { |match|
        t_name = table_name_stack[match.size * -1]
        fail ArgumentError, "Name not found for: #{match}" if !t_name
        t_name
      }

      h[:FROM] << str

    when :GROUP_BY, :ORDER_BY
      h[name].concat args

    else
      fail ArgumentError, "Unknown: #{name.inspect}"
    end
  }

  <<-EOF
    SELECT
      #{h[:SELECT].empty? ? '*' : h[:SELECT].join(",\n")}
    FROM
      #{h[:FROM].join "\n"}
    #{ h[:GROUP_BY].empty? ? '' : 'GROUP BY ' + h[:GROUP_BY].join(', ')}
    #{ h[:ORDER_BY].empty? ? '' : 'ORDER BY ' + h[:ORDER_BY].join(', ')}
  EOF
end

.string(*args, &blok) ⇒ Object

Examples:

string( "...", dig)
string( dig ) { FROM ... }



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# File 'lib/i_dig_sql.rb', line 95

def string *args, &blok
  dig   = args.pop
  str   = args.shift || box_to_string(Box.new &blok)
  s     = str.dup
  withs = []

  while s[HAS_VAR]
    s.gsub!(/\{\{\s?([^\}]+)\s?\}\}/) do |match|
      pieces = $1.split
      name   = pieces.shift
      key    = name.to_sym
      args   = pieces
      withs << key
      withs.concat(dig.sql(key)[:withs]) if dig.sqls.has_key?(key)
      case args.size
      when 0
        name
      else
        "SELECT #{args.join ', '} FROM #{name}"
      end # === case
    end
  end # === while s HAS_VAR

  with = if withs.empty?
           ""
         else
           maps  = []
           done  = {}
           withs.uniq!
           withs.each { |name|
             next if done[name]
             fragment = dig.sql(name)[:base]
             (fragment = fragment.gsub(/^/, "    ")) if ENV['IS_DEV']
             maps << "#{name} AS (\n#{fragment}\n  )"
             done[name] = true
           } # === each withs

           %^WITH\n  #{maps.join ",\n  "}\n\n^
         end

  [with + s, s, withs]
end

Instance Method Details

#pair(name = :SQL, vars = {}) ⇒ Object

def sql



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# File 'lib/i_dig_sql.rb', line 183

def pair name = :SQL, vars = {}
  @vars.freeze unless @vars.frozen?
  [sql(name)[:complete], @vars.merge(vars)]
end

#sql(name, *args, &blok) ⇒ Object

Example:

sql(:name)
sql(:name, 'string')
sql(:name) { FROM ... }



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# File 'lib/i_dig_sql.rb', line 167

def sql name, *args, &blok
  case

  when args.size == 0 && !block_given?
    @sqls[name]

  when (args.size == 0 && block_given?) || args.size == 1
    @sqls[name] = H.new
    @sqls[name][:complete], @sqls[name][:base], @sqls[name][:withs] = I_Dig_Sql.string(*(args), self, &blok)

  else
    fail ArgumentError, "Unknown args: #{args.inspect}"

  end # === case
end

#var(name, *args) ⇒ Object

def initialize



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# File 'lib/i_dig_sql.rb', line 147

def var name, *args
  case args.size

  when 0
    @vars[name]

  when 1
    @vars[name] = args.first

  else
    fail ArgumentError, "Unknown args: #{args.inspect}"

  end # === case
end