> For the complete documentation index, see [llms.txt](https://ploegert.gitbook.io/til/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ploegert.gitbook.io/til/programmy/rails.md).

# rails

- [Add A Check Constraint To A Table](https://ploegert.gitbook.io/til/programmy/rails/add-a-check-constraint-to-a-table.md)
- [Add A Foreign Key Reference To A Table](https://ploegert.gitbook.io/til/programmy/rails/add-a-foreign-key-reference-to-a-table.md)
- [Add A Reference Column With An Index](https://ploegert.gitbook.io/til/programmy/rails/add-a-reference-column-with-an-index.md)
- [Add ActiveRecord Error Not Tied To Any Attribute](https://ploegert.gitbook.io/til/programmy/rails/add-activerecord-error-not-tied-to-any-attribute.md)
- [Add React With Webpacker To A New Rails App](https://ploegert.gitbook.io/til/programmy/rails/add-react-with-webpacker-to-a-new-rails-app.md)
- [Add timestamptz Columns With The Migration DSL](https://ploegert.gitbook.io/til/programmy/rails/add-timestamptz-columns-with-the-migration-dsl.md)
- [Access Secrets In A Rails 5.2 App](https://ploegert.gitbook.io/til/programmy/rails/access-secrets-in-a-rails-5-2-app.md)
- [ActiveRecord Query For This Or That](https://ploegert.gitbook.io/til/programmy/rails/active-record-query-for-this-or-that.md)
- [Advance The Date](https://ploegert.gitbook.io/til/programmy/rails/advance-the-date.md)
- [Allow List Params Anywhere With Strong Params](https://ploegert.gitbook.io/til/programmy/rails/allow-list-params-anywhere-with-strong-params.md)
- [All or Nothing Database Transactions](https://ploegert.gitbook.io/til/programmy/rails/all-or-nothing-database-transactions.md)
- [Assert Two Arrays Have The Same Items With RSpec](https://ploegert.gitbook.io/til/programmy/rails/assert-two-arrays-have-the-same-items-with-rspec.md)
- [Attach A File With Capybara](https://ploegert.gitbook.io/til/programmy/rails/attach-a-file-with-capybara.md)
- [Attribute Getter without the Recursion](https://ploegert.gitbook.io/til/programmy/rails/attribute-getter-without-the-recursion.md)
- [Attribute Was](https://ploegert.gitbook.io/til/programmy/rails/attribute-was.md)
- [Autosave False On ActiveRecord Associations](https://ploegert.gitbook.io/til/programmy/rails/autosave-false-on-activerecord-associations.md)
- [Bind Parameters To ActiveRecord SQL Query](https://ploegert.gitbook.io/til/programmy/rails/bind-parameters-to-activerecord-sql-query.md)
- [Build A Hash Of Model Attributes](https://ploegert.gitbook.io/til/programmy/rails/build-a-hash-of-model-attributes.md)
- [Capture Development Emails With Mailhog](https://ploegert.gitbook.io/til/programmy/rails/capture-development-emails-with-mailhog.md)
- [Capybara Page Status Code](https://ploegert.gitbook.io/til/programmy/rails/capybara-page-status-code.md)
- [Cast Common Boolean-Like Values To Booleans](https://ploegert.gitbook.io/til/programmy/rails/cast-common-boolean-like-values-to-booleans.md)
- [Change The Nullability Of A Column](https://ploegert.gitbook.io/til/programmy/rails/change-the-nullability-of-a-column.md)
- [Change The Time Zone Offset Of A DateTime Object](https://ploegert.gitbook.io/til/programmy/rails/change-the-time-zone-offset-of-a-datetime-object.md)
- [Check If ActiveRecord Update Fails](https://ploegert.gitbook.io/til/programmy/rails/check-if-activerecord-update-fails.md)
- [Check If Any Records Have A Null Value](https://ploegert.gitbook.io/til/programmy/rails/check-if-any-records-have-a-null-value.md)
- [Check Specific Attributes On ActiveRecord Array](https://ploegert.gitbook.io/til/programmy/rails/check-specific-attributes-on-activerecord-array.md)
- [Code Statistics For An Application](https://ploegert.gitbook.io/til/programmy/rails/code-statistics-for-an-application.md)
- [Columns With Default Values Are Nil On Create](https://ploegert.gitbook.io/til/programmy/rails/columns-with-default-values-are-nil-on-create.md)
- [Comparing DateTimes Down To Second Precision](https://ploegert.gitbook.io/til/programmy/rails/comparing-datetimes-down-to-second-precision.md)
- [Conditional Class Selectors in Haml](https://ploegert.gitbook.io/til/programmy/rails/conditional-class-selectors-in-haml.md)
- [Convert A Symbol To A Constant](https://ploegert.gitbook.io/til/programmy/rails/convert-a-symbol-to-a-constant.md)
- [Count The Number Of Records By Attribute](https://ploegert.gitbook.io/til/programmy/rails/count-the-number-of-records-by-attribute.md)
- [Create A Custom Named References Column](https://ploegert.gitbook.io/til/programmy/rails/create-a-custom-named-references-column.md)
- [Create A Join Table With The Migration DSL](https://ploegert.gitbook.io/til/programmy/rails/create-a-join-table-with-the-migration-dsl.md)
- [Creating Records of Has\_One Associations](https://ploegert.gitbook.io/til/programmy/rails/creating-records-of-has-one-associations.md)
- [Custom Validation Message](https://ploegert.gitbook.io/til/programmy/rails/custom-validation-message.md)
- [Customize Paths And Helpers For Devise Routes](https://ploegert.gitbook.io/til/programmy/rails/customize-paths-and-helpers-for-devise-routes.md)
- [Customize The Path Of A Resource Route](https://ploegert.gitbook.io/til/programmy/rails/customize-the-path-of-a-resource-route.md)
- [Delete Paranoid Records](https://ploegert.gitbook.io/til/programmy/rails/delete-paranoid-records.md)
- [Demodulize A Class Name](https://ploegert.gitbook.io/til/programmy/rails/demodulize-a-class-name.md)
- [Different Ways To Add A Foreign Key Reference](https://ploegert.gitbook.io/til/programmy/rails/different-ways-to-add-a-foreign-key-reference.md)
- [Disambiguate Where In A Joined Relation](https://ploegert.gitbook.io/til/programmy/rails/disambiguate-where-in-a-joined-relation.md)
- [Ensure Migrations Use The Latest Schema](https://ploegert.gitbook.io/til/programmy/rails/ensure-migrations-use-the-latest-schema.md)
- [Find Or Create A Record With FactoryBot](https://ploegert.gitbook.io/til/programmy/rails/find-or-create-a-record-with-factory-bot.md)
- [Force All Users To Sign Out](https://ploegert.gitbook.io/til/programmy/rails/force-all-users-to-sign-out.md)
- [Generating And Executing SQL](https://ploegert.gitbook.io/til/programmy/rails/generating-and-executing-sql.md)
- [Get An Array Of Values From The Database](https://ploegert.gitbook.io/til/programmy/rails/get-an-array-of-values-from-the-database.md)
- [Get An Empty ActiveRecord Relation](https://ploegert.gitbook.io/til/programmy/rails/get-an-empty-activerecord-relation.md)
- [Get The Column Names For A Model](https://ploegert.gitbook.io/til/programmy/rails/get-the-column-names-for-a-model.md)
- [Get The Current Time](https://ploegert.gitbook.io/til/programmy/rails/get-the-current-time.md)
- [Grab A Random Record From The Database](https://ploegert.gitbook.io/til/programmy/rails/grab-a-random-record-from-the-database.md)
- [Handle Named Arguments In A Rake Task](https://ploegert.gitbook.io/til/programmy/rails/handle-named-arguments-in-a-rake-task.md)
- [Hash Slicing](https://ploegert.gitbook.io/til/programmy/rails/hash-slicing.md)
- [Ignore Poltergeist JavaScript Errors](https://ploegert.gitbook.io/til/programmy/rails/ignore-poltergeist-javascript-errors.md)
- [Include Devise Helpers In Your Controller Tests](https://ploegert.gitbook.io/til/programmy/rails/include-devise-helpers-in-your-controller-tests.md)
- [Inspect Previous Changes To ActiveRecord Object](https://ploegert.gitbook.io/til/programmy/rails/inspect-previous-changes-to-activerecord-object.md)
- [Link To The Current Page With Query Params](https://ploegert.gitbook.io/til/programmy/rails/link-to-the-current-page-with-query-params.md)
- [List All Installable Rails Versions](https://ploegert.gitbook.io/til/programmy/rails/list-all-installable-rails-versions.md)
- [List The Enqueued Jobs](https://ploegert.gitbook.io/til/programmy/rails/list-the-enqueued-jobs.md)
- [Load Records In Batches With find\_each](https://ploegert.gitbook.io/til/programmy/rails/load-records-in-batches-with-find-each.md)
- [Log SQL Queries Executed By ActiveRecord](https://ploegert.gitbook.io/til/programmy/rails/log-sql-queries-executed-by-activerecord.md)
- [Mark A Migration As Irreversible](https://ploegert.gitbook.io/til/programmy/rails/mark-a-migration-as-irreversible.md)
- [Make ActionMailer Synchronous In Test](https://ploegert.gitbook.io/til/programmy/rails/make-action-mailer-synchronous-in-test.md)
- [Manually Run A Migration From Rails Console](https://ploegert.gitbook.io/til/programmy/rails/manually-run-a-migration-from-rails-console.md)
- [Mark For Destruction](https://ploegert.gitbook.io/til/programmy/rails/mark-for-destruction.md)
- [Mask An ActiveRecord Attribute](https://ploegert.gitbook.io/til/programmy/rails/mask-an-activerecord-attribute.md)
- [Merge A Scope Into An ActiveRecord Query](https://ploegert.gitbook.io/til/programmy/rails/merge-a-scope-into-an-activerecord-query.md)
- [Migrating Up Down Up](https://ploegert.gitbook.io/til/programmy/rails/migrating-up-down-up.md)
- [Order Matters For rescue\_from Blocks](https://ploegert.gitbook.io/til/programmy/rails/order-matters-for-rescue-from-blocks.md)
- [Params Includes Submission Button Info](https://ploegert.gitbook.io/til/programmy/rails/params-includes-submission-button-info.md)
- [Parse Query Params From A URL](https://ploegert.gitbook.io/til/programmy/rails/parse-query-params-from-a-url.md)
- [Perform SQL Explain With ActiveRecord](https://ploegert.gitbook.io/til/programmy/rails/perform-sql-explain-with-activerecord.md)
- [Polymorphic Path Helpers](https://ploegert.gitbook.io/til/programmy/rails/polymorphic-path-helpers.md)
- [Pretend Generations](https://ploegert.gitbook.io/til/programmy/rails/pretend-generations.md)
- [Prevent Writes With A Sandboxed Rails Console](https://ploegert.gitbook.io/til/programmy/rails/prevent-writes-with-a-sandboxed-rails-console.md)
- [Query A Single Value From The Database](https://ploegert.gitbook.io/til/programmy/rails/query-a-single-value-from-the-database.md)
- [Read In Environment-Specific Config Values](https://ploegert.gitbook.io/til/programmy/rails/read-in-environment-specific-config-values.md)
- [Read-Only Models](https://ploegert.gitbook.io/til/programmy/rails/read-only-models.md)
- [Remove The Default Value On A Column](https://ploegert.gitbook.io/til/programmy/rails/remove-the-default-value-on-a-column.md)
- [Render An Alternative ActionMailer Template](https://ploegert.gitbook.io/til/programmy/rails/render-an-alternative-action-mailer-template.md)
- [Render The Response Body In Controller Specs](https://ploegert.gitbook.io/til/programmy/rails/render-the-response-body-in-controller-specs.md)
- [Replace An Index With A Unique Index](https://ploegert.gitbook.io/til/programmy/rails/replace-an-index-with-a-unique-index.md)
- [Rescue From](https://ploegert.gitbook.io/til/programmy/rails/rescue-from.md)
- [Rescue From With A Separate Method](https://ploegert.gitbook.io/til/programmy/rails/rescue-from-with-a-separate-method.md)
- [Retrieve An Object If It Exists](https://ploegert.gitbook.io/til/programmy/rails/retrieve-an-object-if-it-exists.md)
- [Rollback A Specific Migration Out Of Order](https://ploegert.gitbook.io/til/programmy/rails/rollback-a-specific-migration-out-of-order.md)
- [Rounding Numbers With Precision](https://ploegert.gitbook.io/til/programmy/rails/rounding-numbers-with-precision.md)
- [Schedule Sidekiq Jobs Out Into The Future](https://ploegert.gitbook.io/til/programmy/rails/schedule-sidekiq-jobs-out-into-the-future.md)
- [Secure Passwords With Rails And Bcrypt](https://ploegert.gitbook.io/til/programmy/rails/secure-passwords-with-rails-and-bcrypt.md)
- [Select A Select By Selector](https://ploegert.gitbook.io/til/programmy/rails/select-a-select-by-selector.md)
- [Select Value For SQL Counts](https://ploegert.gitbook.io/til/programmy/rails/select-value-for-sql-counts.md)
- [Serialize With fast\_jsonapi In A Rails App](https://ploegert.gitbook.io/til/programmy/rails/serialize-with-fast-jsonapi-in-a-rails-app.md)
- [Set A Timestamp Field To The Current Time](https://ploegert.gitbook.io/til/programmy/rails/set-a-timestamp-field-to-the-current-time.md)
- [Set default\_url\_options For Entire Application](https://ploegert.gitbook.io/til/programmy/rails/set-default-url-options-for-entire-application.md)
- [Set Schema Search Path](https://ploegert.gitbook.io/til/programmy/rails/set-schema-search-path.md)
- [Set Statement Timeout For All Postgres Connections](https://ploegert.gitbook.io/til/programmy/rails/set-statement-timeout-for-all-postgres-connections.md)
- [Set The Default Development Port](https://ploegert.gitbook.io/til/programmy/rails/set-the-default-development-port.md)
- [Show Pending Migrations](https://ploegert.gitbook.io/til/programmy/rails/show-pending-migrations.md)
- [Show Rails Models With Pry](https://ploegert.gitbook.io/til/programmy/rails/show-rails-models-with-pry.md)
- [Show Rails Routes With Pry](https://ploegert.gitbook.io/til/programmy/rails/show-rails-routes-with-pry.md)
- [Skip Validations When Creating A Record](https://ploegert.gitbook.io/til/programmy/rails/skip-validations-when-creating-a-record.md)
- [Specify New Attributes For #find\_or\_create\_by](https://ploegert.gitbook.io/til/programmy/rails/specify-new-attributes-for-find-or-create-by.md)
- [Temporarily Disable strong\_params](https://ploegert.gitbook.io/til/programmy/rails/temporarily-disable-strong-params.md)
- [Test If An Instance Variable Was Assigned](https://ploegert.gitbook.io/til/programmy/rails/test-if-an-instance-variable-was-assigned.md)
- [Test If deliver\_later Is Called For A Mailer](https://ploegert.gitbook.io/til/programmy/rails/test-if-deliver-later-is-called-for-a-mailer.md)
- [Truncate Almost All Tables](https://ploegert.gitbook.io/til/programmy/rails/truncate-almost-all-tables.md)
- [Update Column Versus Update Attribute](https://ploegert.gitbook.io/til/programmy/rails/update-column-versus-update-attribute.md)
- [Upgrading Your Manifest For Sprocket's 4](https://ploegert.gitbook.io/til/programmy/rails/upgrading-your-manifest-for-sprockets-4.md)
- [Verify And Read A Signed Cookie Value](https://ploegert.gitbook.io/til/programmy/rails/verify-and-read-a-signed-cookie-value.md)
- [Where Am I In The Partial Iteration?](https://ploegert.gitbook.io/til/programmy/rails/where-am-i-in-the-partial-iteration.md)
- [Wipe Out All Precompiled Assets](https://ploegert.gitbook.io/til/programmy/rails/wipe-out-all-precompiled-assets.md)
- [Write Reversible Migration To Set Default](https://ploegert.gitbook.io/til/programmy/rails/write-reversible-migration-to-set-default.md)
- [Write Safer Where Clauses With Placeholders](https://ploegert.gitbook.io/til/programmy/rails/write-safer-where-clauses-with-placeholders.md)


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