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Author SHA1 Message Date
nick-w-nick
06d3ffc179 Merge 295fe153ad into 1f039a8958 2025-01-27 09:18:18 -05:00
jbranchaud
1f039a8958 Add Default Rails Deploy Script On Hatchbox as a devops TIL 2025-01-26 21:12:39 -06:00
jbranchaud
c6eefeac98 Add Count The Number Of Items In An Array as a Postgres TIL 2025-01-25 19:02:13 -06:00
nick-w-nick
295fe153ad added mention of ES6 compatibility
Hello, I've added a small blockquote below the description to indicate that this method of accessing an indefinite number of function arguments has been superseded by the use of the spread operator via rest parameters for ES6+ compatibility.
2022-01-06 11:39:04 -05:00
4 changed files with 89 additions and 1 deletions

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@@ -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).
_1574 TILs and counting..._
_1576 TILs and counting..._
See some of the other learning resources I work on:
- [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
@@ -199,6 +199,7 @@ See some of the other learning resources I work on:
- [Check The Status of All Services](devops/check-the-status-of-all-services.md)
- [Check The Syntax Of nginx Files](devops/check-the-syntax-of-nginx-files.md)
- [Connect To An RDS PostgreSQL Database](devops/connect-to-an-rds-postgresql-database.md)
- [Default Rails Deploy Script On Hatchbox](devops/default-rails-deploy-script-on-hatchbox.md)
- [Determine The IP Address Of A Domain](devops/determine-the-ip-address-of-a-domain.md)
- [Hatchbox Exports Env Vars With asdf](devops/hatchbox-exports-env-vars-with-asdf.md)
- [Path Of The Packets](devops/path-of-the-packets.md)
@@ -780,6 +781,7 @@ See some of the other learning resources I work on:
- [Convert A String To A Timestamp](postgres/convert-a-string-to-a-timestamp.md)
- [Count How Many Records There Are Of Each Type](postgres/count-how-many-records-there-are-of-each-type.md)
- [Count Records By Type](postgres/count-records-by-type.md)
- [Count The Number Of Items In An Array](postgres/count-the-number-of-items-in-an-array.md)
- [Count The Number Of Trues In An Aggregate Query](postgres/count-the-number-of-trues-in-an-aggregate-query.md)
- [Create A Cluster In A Specific Data Directory](postgres/create-a-cluster-in-a-specific-data-directory.md)
- [Create A Composite Primary Key](postgres/create-a-composite-primary-key.md)

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@@ -0,0 +1,28 @@
# Default Rails Deploy Script On Hatchbox
I deployed a Rails app to [Hatchbox](https://hatchbox.io) recently. When
following along in the log during a deploy, I can see most of what is happening
as part of the deploy. Though it is too verbose to look through every line. I'd
rather see the contents of the deploy script.
I did quite a bit of digging around while SSH'd into my hatchbox server, but I
couldn't find if or where that file might be stored.
Instead, there is a [_Help Center_
article](https://hatchbox.relationkit.io/articles/55-what-is-the-default-rails-deploy-script)
where Chris Oliver shares what is in the script.
```bash
bundle install -j $(nproc)
yarn install
bundle exec rails assets:precompile
[[ -n "${CRON}" ]] && bundle exec rails db:migrate
```
It does a parallelized `bundle install`, then a `yarn install` (make sure your
project is using `yarn.lock`), Rails asset precompilation, and then if `CRON`
is set (Cron role is available by checking _Cron_ under _Server
Responsibilities_ for your Hatchbox server), it will run Rails migrations.
From app settings, the deploy script can be overridden, or pre- and post-deploy
steps can be added.

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@@ -5,6 +5,8 @@ an array-like object with all of the arguments to the function. Even if not
all of the arguments are referenced in the function signature, they can
still be accessed via the `arguments` object.
> For ES6+ compatibility, the `spread` operator used via [rest parameters](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/rest_parameters) is preferred over the `arugments` object when accessing an abritrary number of function arguments.
```javascript
function argTest(one) {
console.log(one);

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@@ -0,0 +1,56 @@
# Count The Number Of Items In An Array
There are two ways to count the number of items in an array with PostgreSQL.
The one that might jump out at you or show up at the top of search results is
[`array_length`](https://www.postgresql.org/docs/current/functions-array.html).
```sql
> select array_length(array[1,2,3], 1);
+--------------+
| array_length |
|--------------|
| 3 |
+--------------+
> select array_length(array[[1,2], [3,4]], 2);
+--------------+
| array_length |
|--------------|
| 2 |
+--------------+
```
This requires specifying the dimension at which you want to check the length.
The first example, checking the 1st dimension of a one-dimensional array, seems
like the more common and useful scenario. In the second example, we are
checking the 2nd dimension.
The other way we can determine the number of items in an array is with the
[`cardinality`](https://www.postgresql.org/docs/current/functions-array.html)
function.
> Returns the total number of elements in the array, or 0 if the array is
> empty.
```sql
> select cardinality(array[1,2,3]);
+-------------+
| cardinality |
|-------------|
| 3 |
+-------------+
> select cardinality(array[[1,2], [3,4]]);
+-------------+
| cardinality |
|-------------|
| 4 |
+-------------+
```
This behaves the same as `array_length` for a one-dimensional array and doesn't
require a second argument. Where it gets more interesting is with
multi-dimensional arrays. It returns the total number of elements in the
arrayregardless of the nesting.
[source](https://mattrighetti.com/2025/01/20/you-dont-need-sql-builders)