Module: ActiveRecord::ConnectionAdapters::SchemaStatements

Defined in:
lib/ensured_schema/schema_statements.rb

Instance Method Summary collapse

Instance Method Details

#column_exists?(table_name, column_name, type = nil, options = {}) ⇒ Boolean

Checks to see if a column exists in a given table.

Examples

# Check a column exists
column_exists?(:suppliers, :name)

# Check a column exists of a particular type
column_exists?(:suppliers, :name, :string)

# Check a column exists with a specific definition
column_exists?(:suppliers, :name, :string, :limit => 100)

Returns:

  • (Boolean) 


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# File 'lib/ensured_schema/schema_statements.rb', line 39

def column_exists?(table_name, column_name, type = nil, options = {})
  #debugger
  columns(table_name).any?{ |c| c.name == column_name.to_s &&
                                (!type                 || c.type.to_s == type.to_s) &&
                                (!options[:limit]      || c.limit_exists?(options[:limit])) &&
                                (!options[:precision]  || c.precision == options[:precision]) &&
                                (!options[:scale]      || c.scale == options[:scale]) }
end

#ensure_index(table_name, column_name, options = {}) ⇒ Object 



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# File 'lib/ensured_schema/schema_statements.rb', line 60

def ensure_index(table_name, column_name, options = {})
  unless new_index_exists?(table_name, column_name, options)
    add_index(table_name, column_name, options)
  end
end

#ensure_table(table_name) {|EnsuredTable.new(table_name, self)| ... } ⇒ Object

Yields:



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# File 'lib/ensured_schema/schema_statements.rb', line 56

def ensure_table(table_name)
  yield EnsuredTable.new(table_name, self)
end

#new_index_exists?(table_name, column_name, options = {}) ⇒ Boolean

Checks to see if an index exists on a table for a given index definition

Examples

# Check an index exists
index_exists?(:suppliers, :company_id)

# Check an index on multiple columns exists
index_exists?(:suppliers, [:company_id, :company_type])

# Check a unique index exists
index_exists?(:suppliers, :company_id, :unique => true)

# Check an index with a custom name exists
index_exists?(:suppliers, :company_id, :name => "idx_company_id"

Returns:

  • (Boolean) 


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# File 'lib/ensured_schema/schema_statements.rb', line 18

def new_index_exists?(table_name, column_name, options = {}) # Don't overwrite existing index_exists?
  column_names = Array.wrap(column_name)
  index_name = options.key?(:name) ? options[:name].to_s : index_name(table_name, :column => column_names)
  if options[:unique]
    indexes(table_name).any?{ |i| i.unique && i.name == index_name }
  else
    indexes(table_name).any?{ |i| i.name == index_name }
  end
end

#table(table_name, options = {}, &block) ⇒ Object 



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# File 'lib/ensured_schema/schema_statements.rb', line 48

def table(table_name, options = {}, &block)
  if table_exists?(table_name)
    ensure_table(table_name, &block) # what to do about changing table options
  else
    create_table(table_name, options, &block)
  end
end