adding skills and site

2026-02-03 12:27:57 -08:00
parent ad37eda106
commit 2bc3b78be8
64 changed files with 20081 additions and 0 deletions
@@ -0,0 +1,185 @@
+---
+name: how-to-store-sqlite-as-nosql-store
+description: Discover how to leverage SQLite's JSON support to build a NoSQL-like document store, complete with TTL-based expiration, within this powerful embedded database.
+metadata:
+  url: https://rodydavis.com/posts/sqlite/no-sql
+  last_modified: Tue, 03 Feb 2026 20:04:37 GMT
+---
+
+# How to store SQLite as NoSQL Store
+
+
+[SQLite](https://www.sqlite.org/) is a very capable edge database that can store various shapes of data.
+
+[NoSQL databases](https://www.mongodb.com/nosql-explained#:~:text=Some%20say%20the%20term%20%E2%80%9CNoSQL,format%20other%20than%20relational%20tables.) are very popular due to the schema-less nature of storing of the data but it is totally possible to store these documents in SQLite.
+
+SQLite actually has great [JSON support](https://www.sqlite.org/json1.html) and even supports [JSONB](https://sqlite.org/draft/jsonb.html).
+
+## Create the table 
+
+To store JSON documents we need to create a table to store the values as strings.
+
+```
+CREATE TABLE documents (
+  path TEXT NOT NULL PRIMARY KEY,
+  data TEXT,
+  ttl INTEGER,
+  created INTEGER NOT NULL,
+  updated INTEGER NOT NULL,
+  UNIQUE(path)
+);
+```
+
+path
+
+data
+
+ttl
+
+created
+
+updated
+
+/posts/1
+
+{"id":1}
+
+NULL
+
+0
+
+0
+
+/posts/2
+
+{"id":2}
+
+NULL
+
+0
+
+0
+
+/users/1
+
+{"id":1}
+
+NULL
+
+0
+
+0
+
+The basic idea is to store a JSON object and an unique path.
+
+There is an optional [TTL](https://www.cloudflare.com/learning/cdn/glossary/time-to-live-ttl/#:~:text=What%20is%20time%2Dto%2Dlive%20\(TTL\)%20in%20networking,CDN%20caching%20and%20DNS%20caching.) to automatically delete rows when they reach the stale date.
+
+## Save a document 
+
+To save a document we can encode our JSON as a string or binary and save in in the table with a unique path.
+
+```
+INSERT OR REPLACE 
+INTO documents (path, data, ttl, created, updated) 
+VALUES (:path, :data, :ttl, :created, :updated)
+RETURNING *;
+```
+
+You can also use JSON functions to save the Object to a valid JSON string.
+
+```
+INSERT OR REPLACE 
+INTO documents (path, data, ttl, created, updated) 
+VALUES ("/posts/1", json('{"id" 1}'), NULL, 0, 0)
+RETURNING *;
+```
+
+path
+
+data
+
+ttl
+
+created
+
+updated
+
+/posts/1
+
+{"id":1}
+
+NULL
+
+0
+
+0
+
+## Reading a document 
+
+To read a document we just need the path. If a TTL is set we can [calculate if the current date](https://www.sqlite.org/lang_datefunc.html) is greater than the offset and not return the document.
+
+```
+SELECT * FROM documents 
+WHERE path = :path
+AND (
+	(ttl IS NOT NULL AND ttl + updated < unixepoch())
+	OR
+	ttl IS NULL
+);
+```
+
+path
+
+data
+
+ttl
+
+created
+
+updated
+
+/posts/1
+
+{"id":1}
+
+NULL
+
+0
+
+0
+
+## Get documents for a collection 
+
+We can query all the docs for a given collection using some built-in functions and a path prefix:
+
+```
+SELECT *
+FROM documents 
+WHERE (
+	path LIKE :prefix
+	AND
+	(LENGTH(path) - LENGTH(REPLACE(path, '/', ''))) = (LENGTH(:prefix) - LENGTH(REPLACE(:prefix, '/', '')))
+)
+AND (
+	(ttl IS NOT NULL AND ttl + updated < unixepoch())
+	OR
+	ttl IS NULL
+)
+ORDER BY created;
+```
+
+It is expected to search for a :prefix with the `/%` at the end:
+
+`"/my/path/%" // search for /my/path`
+
+## Deleting expired documents 
+
+Using the TTL field we can delete all expired documents:
+
+```
+DELETE FROM documents
+WHERE ttl IS NOT NULL
+AND ttl + updated < unixepoch();
+```
+
+## Demo