Class: Oci8Simple::Describe

Inherits:
Object
  • Object
show all
Includes:
Command
Defined in:
lib/oci8_simple/describe.rb

Overview

Description

This class creates a string describing a table’s columns, intended to be displayed in a fixed-width font.

Usage

Oci8Simple::Describe.new("development").run("users")

Constant Summary collapse

SPACE_BETWEEN = 
2
FIELDS = 
[
  {:select => "NULLABLE",           :header => "Required", :content => :format_nullable, :right => true},
  {:select => "lower(COLUMN_NAME)", :header=> "Name"},
  {:select => "lower(DATA_TYPE)",   :header => "Type"},
  {:select => "DATA_LENGTH",        :header => "Size", :content => :format_size},
  {:select => "CHAR_USED",          :header => "Char?", :content => :format_char_used},   
  {:select => "CHAR_LENGTH",        :header => "Char_size", :content => :format_char_length},
  {:select => "DATA_PRECISION",     :header => "Precision"}, 
  {:select => "DATA_SCALE",         :header => "Scale"},
  {:select => "DATA_DEFAULT",       :header => "Default", :content => :format_default, :max => 10}
]

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Command

included

Constructor Details

#initialize(env = nil) ⇒ Describe

Returns a new instance of Describe.



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# File 'lib/oci8_simple/describe.rb', line 35

def initialize(env=nil)
  @env = env || "development"
end

Class Method Details

.run_from_argv ⇒ Object 



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# File 'lib/oci8_simple/describe.rb', line 43

def self.run_from_argv
  o = parse_options(self.usage)
  if(ARGV[0].nil?)
    puts o
  else
    puts self.new(@options[:environment]).run(ARGV[0])
  end
end

.usage ⇒ Object 



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# File 'lib/oci8_simple/describe.rb', line 39

def self.usage
  "Usage: #{$0} TABLE_NAME [ENVIRONMENT]"
end

Instance Method Details

#run(table) ⇒ Object 



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# File 'lib/oci8_simple/describe.rb', line 23

def run(table)
  sql = <<-SQL
    select #{select_fields} 
    from user_tab_columns 
    where table_name='#{table.upcase}' 
    order by column_name asc
  SQL
  results = client.run(sql)
  calculate_widths(results)
  format_results(results)
end