Add Label Dollar-Quoted Strings With A Tag as a Postgres TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1207 TILs and counting..._
+_1209 TILs and counting..._
 
 ---
 
@@ -618,6 +618,7 @@ _1207 TILs and counting..._
 - [Integers In Postgres](postgres/integers-in-postgres.md)
 - [Intervals Of Time By Week](postgres/intervals-of-time-by-week.md)
 - [Is It Null Or Not Null?](postgres/is-it-null-or-not-null.md)
+- [Label Dollar-Quoted Strings With A Tag](postgres/label-dollar-quoted-strings-with-a-tag.md)
 - [Limit Execution Time Of Statements](postgres/limit-execution-time-of-statements.md)
 - [List All Columns Of A Specific Type](postgres/list-all-columns-of-a-specific-type.md)
 - [List All Rows In A Table](postgres/list-all-rows-in-a-table.md)
@@ -782,6 +783,7 @@ _1207 TILs and counting..._
 - [Retrieve An Object If It Exists](rails/retrieve-an-object-if-it-exists.md)
 - [Rollback A Specific Migration Out Of Order](rails/rollback-a-specific-migration-out-of-order.md)
 - [Rounding Numbers With Precision](rails/rounding-numbers-with-precision.md)
+- [Run A Rake Task Programmatically](rails/run-a-rake-task-programmatically.md)
 - [Run Some Code Whenever Rails Console Starts](rails/run-some-code-whenever-rails-console-starts.md)
 - [Schedule Sidekiq Jobs Out Into The Future](rails/schedule-sidekiq-jobs-out-into-the-future.md)
 - [Secure Passwords With Rails And Bcrypt](rails/secure-passwords-with-rails-and-bcrypt.md)

postgres/label-dollar-quoted-strings-with-a-tag.md

@@ -0,0 +1,38 @@
+# Label Dollar-Quoted Strings With A Tag
+
+In [Escaping String Literals with Dollar
+Quoting](escaping-string-literals-with-dollar-quoting.md), I showed how
+PostgreSQL supports escaped string literals so that you don't have to put
+backslashes everywhere. This is done by opening and closing the string with
+`$$`.
+
+What if your string literal is going to contain a sequence of two `$` symbols?
+Or a better hypothetical, what if you want to convey some information about
+what the string represents?
+
+For either of these, the _tagged_ dollar-quoting is a great fit.
+
+```sql
+> select $JSON${"name": "Sally's Bistro", "price": "$$$"}$JSON$::jsonb;
+                   jsonb
+--------------------------------------------
+ {"name": "Sally's Bistro", "price": "$$$"}
+(1 row)
+
+> select $JSON${"name": "Sally's Bistro", "price": "$$$"}$JSON$::jsonb->'name' as name;
+       name
+------------------
+ "Sally's Bistro"
+(1 row)
+```
+
+The tagged dollar-quoting allows me to write a string that can be cast to
+`jsonb` without having to think about which characters need to be escaped. In
+the second example, I'm able to interact with it like any `jsonb` entity.
+
+Here, our tag is `JSON`. It helps convey that the string literal represents
+JSON. A tag "follows the same rules as an unquoted identifier, except that it
+cannot contain a dollar sign." The tag goes between the dollar signs and is
+case-sensitive.
+
+[source](https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-DOLLAR-QUOTING)

rails/run-a-rake-task-programmatically.md

@@ -0,0 +1,35 @@
+# Run A Rake Task Programmatically
+
+Typically the way to run a rake task is with the `rake` command from the
+command line.
+
+```bash
+$ rake example:env
+```
+
+What if you have a rake task that you want to invoke as part of a Ruby script
+or from somewhere in your Rails codebase?
+
+Your tasks can be called programmatically as well.
+
+Consider these two rake tasks:
+
+```ruby
+namespace :example do
+  task :env do
+    puts "Current Environment: #{Rails.env.upcase}"
+  end
+
+  task :message, [:msg] do |task, args|
+    puts "Message: #{args[:msg]}"
+  end
+end
+```
+
+These can be called from somewhere else by referencing and invoking them like
+so.
+
+```ruby
+Rake::Task["example:env"].invoke
+Rake::Task["example:message"].invoke("Nice rake task!")
+```