Merge 15337dfd71 into 44e626a086

See [here](https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/) for more explanations:
> We are monitoring telemetry for the usage of these commands and plan to fully disable them on 31st May 2023. Starting 1st June 2023 workflows using save-state or set-output commands via stdout will fail with an error.

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).
 
-_1430 TILs and counting..._
+_1431 TILs and counting..._
 
 ---
 
@@ -734,6 +734,7 @@ _1430 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)

github-actions/capture-an-output-value-for-use-in-a-later-step.md

@@ -23,11 +23,11 @@ version from my `.tool-versions` file with a step that uses `set-output`.
   - name: Read Node.js version to install from `.tool-versions`
     id: nodejs
     run: >-
-      echo "::set-output name=NODE_VERSION::$(
+      echo "NODE_VERSION=$(
         cat .tool-versions |
         grep nodejs |
         sed 's/nodejs \(.*\)$/\1/'
-      )"
+      )" >> $GITHUB_OUTPUT
 ```
 
 `echo` runs the command in the string which sets `NODE_VERSION` as an output
@@ -45,4 +45,4 @@ This output value can be referenced in a later step.
 `steps` has a reference to the `nodejs` step (note the `id` above) which then
 has `outputs` like the `NODE_VERSION`.
 
-[source](https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#using-workflow-commands-to-access-toolkit-functions)
+[source](https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-output-parameter)

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)