method

add_check_constraint

rails latest stable - Class: ActiveRecord::ConnectionAdapters::SchemaStatements

add_check_constraint(table_name, expression, if_not_exists: false, **options)

public

Adds a new check constraint to the table. expression is a String representation of verifiable boolean condition.

add_check_constraint :products, "price > 0", name: "price_check"

generates:

ALTER TABLE "products" ADD CONSTRAINT price_check CHECK (price > 0)

The options hash can include the following keys:

:name: The constraint name. Defaults to chk_rails_<identifier>.
:if_not_exists: Silently ignore if the constraint already exists, rather than raise an error.
:validate: (PostgreSQL only) Specify whether or not the constraint should be validated. Defaults to true.

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 1260
      def add_check_constraint(table_name, expression, if_not_exists: false, **options)
        return unless supports_check_constraints?

        options = check_constraint_options(table_name, expression, options)
        return if if_not_exists && check_constraint_exists?(table_name, **options)

        at = create_alter_table(table_name)
        at.add_check_constraint(expression, options)

        execute schema_creation.accept(at)
      end

add_check_constraint

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