From 1d1b9c49ffc7778516998742d2500f03fcd6c95c Mon Sep 17 00:00:00 2001
From: Gabor Szabo <gabor@szabgab.com>
Date: Thu, 15 Aug 2024 13:15:55 +0300
Subject: [PATCH] add

---
 python/examples/sqlite/in_memory.py  |  8 +++++
 python/examples/sqlite/sql_create.py | 45 +++++++++++++++++-----------
 python/sqlite.md                     | 16 +++++++++-
 3 files changed, 50 insertions(+), 19 deletions(-)
 create mode 100644 python/examples/sqlite/in_memory.py

diff --git a/python/examples/sqlite/in_memory.py b/python/examples/sqlite/in_memory.py
new file mode 100644
index 000000000..95da4e393
--- /dev/null
+++ b/python/examples/sqlite/in_memory.py
@@ -0,0 +1,8 @@
+import sqlite3
+
+conn = sqlite3.connect(":memory:")
+crs = conn.cursor()
+
+# use the database here
+
+conn.close()
diff --git a/python/examples/sqlite/sql_create.py b/python/examples/sqlite/sql_create.py
index 5138fef4f..ce2ca2374 100644
--- a/python/examples/sqlite/sql_create.py
+++ b/python/examples/sqlite/sql_create.py
@@ -1,25 +1,34 @@
 import sqlite3
 
-conn = sqlite3.connect("companies.db")
-crs = conn.cursor()
 
-sql = '''
-    CREATE TABLE companies (
-                    id          INTEGER PRIMARY KEY AUTOINCREMENT,
-                    name        VARCRCHAR(100) UNIQUE NOT NULL,
-                    established INTEGER NOT NULL,
-                    employees   INTEGER DEFAULT 0
-)
-'''
+def create_table(conn):
+    crs = conn.cursor()
 
-try:
-    crs.execute(sql)
-except sqlite3.OperationalError as err:
-    print(f'sqlite error: {err.args[0]}')  # table companies already exists
-    print(f'remove companies.db to show how it works')
+    sql = '''
+        CREATE TABLE companies (
+                        id          INTEGER PRIMARY KEY AUTOINCREMENT,
+                        name        VARCRCHAR(100) UNIQUE NOT NULL,
+                        established INTEGER NOT NULL,
+                        employees   INTEGER DEFAULT 0
+    )
+    '''
 
-conn.commit()
+    try:
+        crs.execute(sql)
+    except sqlite3.OperationalError as err:
+        print(f'sqlite error: {err.args[0]}')  # table companies already exists
+        print(f'remove companies.db to show how it works')
 
-conn.close()
+    conn.commit()
 
-print('done')
+def main():
+    conn = sqlite3.connect("companies.db")
+
+    create_table(conn)
+
+    conn.close()
+
+    print('done')
+
+if __name__ == "__main__":
+    main()
diff --git a/python/sqlite.md b/python/sqlite.md
index 29282df28..c1a840268 100644
--- a/python/sqlite.md
+++ b/python/sqlite.md
@@ -5,7 +5,8 @@
 {id: sqlite3}
 {i: sqlite}
 
-* [sqlite3](http://docs.python.org/library/sqlite3.html)
+* [SQLite](https://sqlite.org/) the most popular embedded relational database.
+* [sqlite3](http://docs.python.org/library/sqlite3.html) - Python library to use SQLite.
 
 
 ## Connecting to SQLite database
@@ -13,8 +14,21 @@
 {i: connect|sqlite}
 {i: cursor|sqlite}
 
+This connects to the database in the given file. If the file does not exist yet this will create the file and prepare it to hold
+an SQLite database. No tables are created at this point and no data is inserted.
+
 ![](examples/sqlite/sql_connect.py)
 
+## Connecting to in-memory SQLite database
+{id: sqlite-in-memory-connect}
+
+We can also create in-memory database.
+
+This is not persistent, but it can be useful to load some data into memory and then do fast SQL queries on
+that database.
+
+![](examples/sqlite/in_memory.py)
+
 
 ## Create TABLE in SQLite
 {id: sqlite-create}