From 4bd7c89e667b733e138a198a4e803b5dcbd1faf3 Mon Sep 17 00:00:00 2001
From: Gabor Szabo <gabor@szabgab.com>
Date: Fri, 16 Aug 2024 09:42:44 +0300
Subject: [PATCH] add

---
 sqlite/examples/update.sql | 18 ++++++++++++++++++
 sqlite/intro.md            | 15 +++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 sqlite/examples/update.sql

diff --git a/sqlite/examples/update.sql b/sqlite/examples/update.sql
new file mode 100644
index 00000000..0c1b52f9
--- /dev/null
+++ b/sqlite/examples/update.sql
@@ -0,0 +1,18 @@
+CREATE TABLE people (
+    name TEXT,
+    grade INTEGER
+);
+
+INSERT INTO people (name, grade) VALUES ('Joe', 40);
+INSERT INTO people (name, grade) VALUES ('Jane', 60);
+SELECT * from people;
+SELECT "";
+
+UPDATE people SET grade = 44 WHERE name = "Joe";
+SELECT * from people;
+SELECT "";
+
+UPDATE people SET grade = (SELECT grade FROM people WHERE name = "Joe") + 1 WHERE name = "Joe";
+SELECT * from people;
+SELECT "";
+
diff --git a/sqlite/intro.md b/sqlite/intro.md
index ccfacda6..23edc9a5 100644
--- a/sqlite/intro.md
+++ b/sqlite/intro.md
@@ -166,8 +166,23 @@ Meaning of life?|42
 ## Transactions
 {id: transactions}
 
+![](examples/transaction.sql)
+
 ## PRAGMA
 {id: pragma}
 
 [PRAGMA](https://sqlite.org/pragma.html)
 
+## UPDATE
+{id: update}
+
+![](examples/update.sql)
+
+
+
+
+* TODO: loading a large CSV file into the database and running queries.
+* TODO: creating a multi-tabe databas, dumping it and then loading it and running queries against it.
+* TODO: FOREIGN KEY - cascading deletition?
+
+