instance method `index_exists?`

Ruby on Rails 4.2.9

Since v2.3.18

Available in: v2.3.18 v3.0.20 v3.1.12 v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

index_exists?(table_name, column_name, options = {})

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

# 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")

Parameters

table_name req
column_name req
options opt = {}

Source

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 61
      def index_exists?(table_name, column_name, options = {})
        column_names = Array(column_name).map(&:to_s)
        index_name = options.key?(:name) ? options[:name].to_s : index_name(table_name, column: column_names)
        checks = []
        checks << lambda { |i| i.name == index_name }
        checks << lambda { |i| i.columns == column_names }
        checks << lambda { |i| i.unique } if options[:unique]

        indexes(table_name).any? { |i| checks.all? { |check| check[i] } }
      end

Defined in activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb line 61 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::ConnectionAdapters::SchemaStatements

Signature

Parameters