Add Fetch Specific Number Of Results 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).
 
-_1524 TILs and counting..._
+_1525 TILs and counting..._
 
 ---
 
@@ -777,6 +777,7 @@ _1524 TILs and counting..._
 - [Escaping String Literals With Dollar Quoting](postgres/escaping-string-literals-with-dollar-quoting.md)
 - [Export Query Results To A CSV](postgres/export-query-results-to-a-csv.md)
 - [Extracting Nested JSON Data](postgres/extracting-nested-json-data.md)
+- [Fetch Specific Number Of Results](postgres/fetch-specific-number-of-results.md)
 - [Find Duplicate Records In Table Without Unique Id](postgres/find-duplicate-records-in-table-without-unique-id.md)
 - [Find Records That Contain Duplicate Values](postgres/find-records-that-contain-duplicate-values.md)
 - [Find Records That Have Multiple Associated Records](postgres/find-records-that-have-multiple-associated-records.md)

postgres/fetch-specific-number-of-results.md

@@ -0,0 +1,42 @@
+# Fetch Specific Number Of Results
+
+If you pull up just about any intro to PostgreSQL (or even SQL), one of the
+first things they are going to teach you is the `limit` clause. This is taught
+as _the_ way for limiting the result set to a specific number of rows.
+
+```sql
+> select title from books limit 4;
++-----------------------+
+| title                 |
+|-----------------------|
+| The Secret History    |
+| A Gentleman in Moscow |
+| Exhalation: Stores    |
+| Annihilation          |
++-----------------------+
+SELECT 4
+```
+
+You might be as surprised as I was to learn that `limit` is not part of the SQL
+standard. It is extremely common for this use case, but the SQL standard
+defines `fetch first N rows only` as the way to fetch a specific number of
+rows. As we can see, [it works identically to `limit
+N`](https://www.postgresql.org/docs/current/sql-select.html#SQL-LIMIT).
+
+```sql
+> select title from books fetch first 4 rows only;
++-----------------------+
+| title                 |
+|-----------------------|
+| The Secret History    |
+| A Gentleman in Moscow |
+| Exhalation: Stores    |
+| Annihilation          |
++-----------------------+
+SELECT 4
+```
+
+The `rows` and `row` keywords are interchangeable which makes statements more
+readable if, for instance, you're doing `... fetch first 1 row only`.
+
+[source](https://www.cybertec-postgresql.com/en/postgresql-limit-vs-fetch-first-rows-with-ties/)