Merge cea4ffc0a3 into 84e2c9c6f4

README.md

@@ -2,15 +2,15 @@
 
 > Today I Learned
 
-A collection of concise write-ups on small things I learn day to day across a
-variety of languages and technologies. These are things that don't really
+A collection of concise write-ups on small things I learn day to day across a 
+variety of languages and technologies. These are things that don't 
 warrant a full blog post. These are things I've picked up by [Learning In
 Public™](https://dev.to/jbranchaud/how-i-built-a-learning-machine-45k9) and
 pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1427 TILs and counting..._
+_1433 TILs and counting..._
 
 ---
 
@@ -462,6 +462,7 @@ _1427 TILs and counting..._
 - [Find Where Yarn Is Installing Binaries](javascript/find-where-yarn-is-installing-binaries.md)
 - [for...in Iterates Over Object Properties](javascript/for-in-iterates-over-object-properties.md)
 - [Format A Decimal To A Fixed Number Of Digits](javascript/format-a-decimal-to-a-fixed-number-of-digits.md)
+- [Format Time Zone Identifier](javascript/format-time-zone-identifier.md)
 - [Formatting Values With Units For Display](javascript/formatting-values-with-units-for-display.md)
 - [Freeze An Object, Sorta](javascript/freeze-an-object-sorta.md)
 - [Generate A V4 UUID In The Browser](javascript/generate-a-v4-uuid-in-the-browser.md)
@@ -610,6 +611,7 @@ _1427 TILs and counting..._
 - [List Databases And Tables](mysql/list-databases-and-tables.md)
 - [Run Statements In A Transaction](mysql/run-statements-in-a-transaction.md)
 - [Select Rows After An Offset](mysql/select-rows-after-an-offset.md)
+- [Set Value On Null JSON Column](mysql/set-value-on-null-json-column.md)
 - [Show Create Statement For A Table](mysql/show-create-statement-for-a-table.md)
 - [Show Tables That Match A Pattern](mysql/show-tables-that-match-a-pattern.md)
 - [Show Indexes For A Table](mysql/show-indexes-for-a-table.md)
@@ -732,6 +734,7 @@ _1427 TILs and counting..._
 - [Generate Series Of Numbers](postgres/generate-series-of-numbers.md)
 - [Generating UUIDs With pgcrypto](postgres/generating-uuids-with-pgcrypto.md)
 - [Get A Quick Approximate Count Of A Table](postgres/get-a-quick-approximate-count-of-a-table.md)
+- [Get Row Count For Most Recent Query](postgres/get-row-count-for-most-recent-query.md)
 - [Get The Size On Disk of An Index](postgres/get-the-size-on-disk-of-an-index.md)
 - [Get The Size Of A Database](postgres/get-the-size-of-a-database.md)
 - [Get The Size Of A Table](postgres/get-the-size-of-a-table.md)
@@ -822,10 +825,12 @@ _1427 TILs and counting..._
 
 - [Apply Separate Formatting With A Blank Line](prisma/apply-separate-formatting-with-a-blank-line.md)
 - [Batch Insert Records With createMany](prisma/batch-insert-records-with-create-many.md)
+- [Check If Database And Schema Are Not In Sync](prisma/check-if-database-and-schema-are-not-in-sync.md)
 - [Configure Client To Log SQL Queries](prisma/configure-client-to-log-sql-queries.md)
 - [Execute A Raw SQL Query](prisma/execute-a-raw-sql-query.md)
 - [Grab A Limited Set Of Records](prisma/grab-a-limited-set-of-records.md)
 - [Open Connections To Multiple Databases](prisma/open-connections-to-multiple-databases.md)
+- [Override Table Name For Prisma Model](prisma/override-table-name-for-prisma-model.md)
 - [Specify Alternate Location For Prisma Schema](prisma/specify-alternate-location-for-prisma-schema.md)
 
 ### Python
@@ -1373,6 +1378,7 @@ _1427 TILs and counting..._
 - [Find Files With fd](unix/find-files-with-fd.md)
 - [Find Newer Files](unix/find-newer-files.md)
 - [Find Occurrences Of Multiple Values With Ripgrep](unix/find-occurrences-of-multiple-values-with-ripgrep.md)
+- [Find Top-Level Directories Matching A Pattern](unix/find-top-level-directories-matching-a-pattern.md)
 - [Fix Unlinked Node Binaries With asdf](unix/fix-unlinked-node-binaries-with-asdf.md)
 - [Forward Multiple Ports Over SSH](unix/forward-multiple-ports-over-ssh.md)
 - [Generate A SAML Key And Certificate Pair](unix/generate-a-saml-key-and-certificate-pair.md)

javascript/format-time-zone-identifier.md

@@ -0,0 +1,34 @@
+# Format Time Zone Identifier
+
+Though there are surely libraries that can help with this task, we now have
+full support in the [`Intl.DateTimeFormat`
+API](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat)
+for formatting a date's time zone identifier in various ways.
+
+To do this, we have to create a formatter specifying the locale, the `timeZone`
+option, and any formatting options. For the formatting, I'll try the
+`timeZoneName` with both `short` and `longGeneric`.
+
+Then we `formatToParts` on any date object and extract the `timeZoneName`
+value:
+
+```javascript
+const options = { timeZone: 'America/Chicago', timeZoneName: "short" }
+const formatter = new Intl.DateTimeFormat("en-US", options)
+
+formatter.formatToParts(new Date()).find((part) => part.type === "timeZoneName").value
+//=> 'CDT'
+```
+
+Now, let's try this for `longGeneric`:
+
+```javascript
+const options = { timeZone: 'America/Chicago', timeZoneName: "longGeneric" }
+const formatter = new Intl.DateTimeFormat("en-US", options)
+
+formatter.formatToParts(new Date()).find((part) => part.type === "timeZoneName").value
+//=> 'Central Time'
+```
+
+There are several more options for the `timeZoneName` as well as a bunch more
+you can do with the `Intl.DateTimeFormat` API.

mysql/set-value-on-null-json-column.md

@@ -0,0 +1,44 @@
+# Set Value On Null JSON Column
+
+To set a key-value pair on a JSON field, you can reach for
+[MySQL's `json_set`](https://dev.mysql.com/doc/refman/8.0/en/json-modification-functions.html#function_json-set)
+or one of [the other JSON setter
+functions](https://dev.mysql.com/doc/refman/8.0/en/json-modification-functions.html).
+
+However, if the JSON field you are updating is `null`, you might get an
+unexpected result.
+
+```sql
+> update User
+    set metadata = json_set(metadata, '$.discord_id', 'discord_123')
+    where id = 123;
+
+Query OK, 0 rows affected (0.00 sec)
+Rows matched: 1  Changed: 0  Warnings: 0
+```
+
+We can see that the `where` clause matched on a single row as expected, but
+right above that it says _0 rows affected_.
+
+What happened?
+
+The `json_set` function is not able to set a key-value pair on `null`. It needs
+a JSON object to work on.
+
+There are a number of ways to get around this. I find that
+[`coalesce`](https://dev.mysql.com/doc/refman/8.0/en/comparison-operators.html#function_coalesce)
+is a natural way to handle this. If `metadata` happens to be `null`, then we
+_coalesce_ it to `'{}'` (an empty object).
+
+```sql
+> update User
+    set metadata = json_set(coalesce(metadata, '{}'), '$.discord_id', 'discord_123')
+    where id = 123;
+
+Query OK, 1 row affected (0.02 sec)
+Rows matched: 1  Changed: 1  Warnings: 0
+```
+
+It updates as expected. That same statement will work on a row where `metadata`
+already contains a JSON object since the `coalesce` will resolve to that
+instead of the empty object.

postgres/get-row-count-for-most-recent-query.md

@@ -0,0 +1,65 @@
+# Get Row Count For Most Recent Query
+
+Anytime you execute a query in `psql`, there is a _row count_ associated with
+that query. This is most naturally understood with a `select` query where a
+discreet number of rows are returned. We typically see the row count (e.g. `(19
+rows)`) right below the result set.
+
+You can always reference the row count of the most recent query with [the
+`:ROW_COUNT`
+variable](https://www.postgresql.org/docs/current/app-psql.html#APP-PSQL-VARIABLES-ROW-COUNT).
+Here we use `\echo` to print it out.
+
+```sql
+> select generate_series(2,20);
+ generate_series
+-----------------
+               2
+               3
+               4
+               5
+               6
+               7
+               8
+               9
+              10
+              11
+              12
+              13
+              14
+              15
+              16
+              17
+              18
+              19
+              20
+(19 rows)
+
+Time: 12.338 ms
+> \echo :ROW_COUNT
+19
+```
+
+For some queries, like one that induces a pager (e.g. `less`) to be used,
+you'll lose track of the row count once the pager closes. This is where being
+able to reference the row count without rerunning the query is most useful.
+
+```sql
+> select generate_series(2,2000);
+Time: 9.815 ms
+> \echo :ROW_COUNT
+1999
+```
+
+Notice, we can also get a row count from other kinds of queries like this
+`insert` statement.
+
+```sql
+> insert into users (id) values (50001), (50002), (50003);
+INSERT 0 3
+Time: 2.804 ms
+> \echo :ROW_COUNT
+3
+```
+
+[source](https://postgresql.verite.pro/blog/2024/05/13/advanced-psql-coproc.html)

prisma/check-if-database-and-schema-are-not-in-sync.md

@@ -0,0 +1,37 @@
+# Check If Database And Schema Are Not In Sync
+
+The [`prisma migrate
+diff`](https://www.prisma.io/docs/orm/reference/prisma-cli-reference#migrate-diff)
+command is a versatile tool that can be used to check if there is a difference
+between two sources. In this case, we want to check if our database is in sync
+with the `schema.prisma` file for our project.
+
+If we have made changes to the schema file, but haven't yet migrated or pushed
+those changes to our local database, then we want to be notified of that
+mismatch.
+
+We'll point at the schema file with `--to-schema-datamodel` and at our local
+database with `--from-url`.
+
+```bash
+❯ npx prisma migrate diff \
+    --to-schema-datamodel ./prisma/schema.prisma \
+    --from-url mysql://root@localhost:3309/kcd-products
+
+[*] Changed the `User` table
+  [+] Added column `metadata`
+```
+
+In the case where there is a different, we see an output summary of the diff.
+
+Let's say we've applied our changes (`prisma db push`) to our local database.
+If we now run that same command again, we can see that no difference is
+detected and our database is in sync with our schema.
+
+```bash
+❯ npx prisma migrate diff \
+    --to-schema-datamodel ./prisma/schema.prisma \
+    --from-url mysql://root@localhost:3309/kcd-products
+
+No difference detected.
+```

prisma/override-table-name-for-prisma-model.md

@@ -0,0 +1,42 @@
+# Override Table Name For Prisma Model
+
+When defining your Prisma schema, you'll add models to your
+`prisma/schema.prisma` file that look something like this:
+
+```
+model Book {
+  id               BigInt   @id @default(autoincrement()) @db.BigInt
+  title            String
+  author           String
+  publication_year Int
+  created_at       DateTime @default(now())
+  updated_at       DateTime @updatedAt
+}
+```
+
+The prisma client (ORM-layer) that gets generated will have a `Book` type and
+you'll be able to reference the model to, for instance, create a record with
+`prisma.book.create(...)`. Both of these things are derived from the model
+name: `Book`.
+
+The other thing that is derived from the model name is the name given to the
+underlying database table. So you end up with a table called `Book`. You may,
+however, prefer a table naming convention where this one would be named `books`
+(snake_case and pluralized).
+
+To achieve that, you have to manually override the table name with [the `@@map`
+directive](https://www.prisma.io/docs/orm/reference/prisma-schema-reference#map-1).
+Add it toward the bottom of the model like so:
+
+```
+model Book {
+  id               BigInt   @id @default(autoincrement()) @db.BigInt
+  title            String
+  author           String
+  publication_year Int
+  created_at       DateTime @default(now())
+  updated_at       DateTime @updatedAt
+
+  @@map("books")
+}
+```

unix/find-top-level-directories-matching-a-pattern.md

@@ -0,0 +1,36 @@
+# Find Top-Level Directories Matching A Pattern
+
+I like using [`fd`](https://github.com/sharkdp/fd) as an alternative to `find`.
+In my experience it is more intuitive to use. For instance, I wanted to find
+all the top-level directories in my current directory that contained the word
+`next`. I was able to get the command mostly right by guessing the flags, only
+checking the man page once.
+
+On my first attempt, it prompted me with a suggestion for a flag that wasn't
+quite right. I tried `--depth`, but it should have been `--maxdepth`.
+
+```bash
+$ fd --depth 0 next ./
+error: Found argument '--depth' which wasn't expected, or isn't valid in this context
+        Did you mean --maxdepth?
+```
+
+Then I checked the man page for how to specify the file type as _directory_ --
+using `-t` or `--type` with `d`.
+
+And here is the command that gets me all top-level directories matching `next`
+in my current directory:
+
+```bash
+$ fd --maxdepth 1 --type d next ./
+
+bookshelf-nextjs-prisma-postgres
+bookshelf-prisma-nextjs-planetscale
+my-next-app
+next-bookshelf
+next-personal-site
+next-sanity-v3-example
+try-trpc-next
+```
+
+See `man fd` for more details.