a lot of early diesel stuff

Cargo.lock

@@ -539,6 +539,41 @@ dependencies = [
  "regex-syntax 0.7.5",
 ]
 
+[[package]]
+name = "darling"
+version = "0.20.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "83b2eb4d90d12bdda5ed17de686c2acb4c57914f8f921b8da7e112b5a36f3fe1"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.20.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "622687fe0bac72a04e5599029151f5796111b90f1baaa9b544d807a5e31cd120"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim",
+ "syn",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.20.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "733cabb43482b1a1b53eee8583c2b9e8684d592215ea83efd305dd31bc2f0178"
+dependencies = [
+ "darling_core",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "data-encoding"
 version = "2.6.0"
@@ -565,9 +600,52 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "diesel"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62d6dcd069e7b5fe49a302411f759d4cf1cf2c27fe798ef46fb8baefc053dd2b"
+dependencies = [
+ "diesel_derives",
+ "libsqlite3-sys",
+ "serde_json",
+ "time",
+ "uuid",
+]
+
 [[package]]
 name = "diesel-demo"
 version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "diesel",
+ "dotenvy",
+ "libpt",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "diesel_derives"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59de76a222c2b8059f789cbe07afbfd8deb8c31dd0bc2a21f85e256c1def8259"
+dependencies = [
+ "diesel_table_macro_syntax",
+ "dsl_auto_type",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "diesel_table_macro_syntax"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "209c735641a413bc68c4923a9d6ad4bcb3ca306b794edaa7eb0b3228a99ffb25"
+dependencies = [
+ "syn",
+]
 
 [[package]]
 name = "digest"
@@ -591,12 +669,32 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "dotenvy"
+version = "0.15.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1aaf95b3e5c8f23aa320147307562d361db0ae0d51242340f558153b4eb2439b"
+
 [[package]]
 name = "drain_filter_polyfill"
 version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "669a445ee724c5c69b1b06fe0b63e70a1c84bc9bb7d9696cd4f4e3ec45050408"
 
+[[package]]
+name = "dsl_auto_type"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0892a17df262a24294c382f0d5997571006e7a4348b4327557c4ff1cd4a8bccc"
+dependencies = [
+ "darling",
+ "either",
+ "heck 0.5.0",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "echargs"
 version = "0.1.0"
@@ -1069,6 +1167,12 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
 [[package]]
 name = "idna"
 version = "0.5.0"
@@ -2590,6 +2694,12 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
+[[package]]
+name = "uuid"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d023da39d1fde5a8a3fe1f3e01ca9632ada0a63e9797de55a879d6e2236277be"
+
 [[package]]
 name = "valuable"
 version = "0.1.0"

members/diesel-demo/.env

@@ -0,0 +1 @@
+export DATABASE_URL=./data/dieseldemo.db

members/diesel-demo/Cargo.toml

@@ -4,3 +4,9 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+anyhow.workspace = true
+diesel = { version = "2.2.1", features = ["serde_json", "sqlite", "uuid"] }
+dotenvy = "0.15.7"
+libpt.workspace = true
+serde = { workspace = true, features = ["serde_derive"] }
+serde_json.workspace = true

members/diesel-demo/README.md

@@ -0,0 +1,19 @@
+# Diesel seems more complex
+
+This project uses sqlite as I can't be bothered to host a postgres instance
+just for this.
+
+## Setup
+
+* Install diesel and the diesel CLI tool.
+* `DATABASE_URL=./data/dieseldemo.db diesel setup`
+* We create migrations up/down and fill them with sql to do something and undo something
+* Alternatively, we can use a rust macro to define schemes that become sql
+  through magic. I like this way better for this project because I learn more
+  diesel and also because it avoids having to deal with incompatibilities of the
+  database types (maybe).
+    * Run `diesel migration generate --diff-schema create_posts`
+
+## Ressources
+
+* [Official Guide](https://diesel.rs/guides/getting-started)

members/diesel-demo/diesel.toml

@@ -0,0 +1,9 @@
+# For documentation on how to configure this file,
+# see https://diesel.rs/guides/configuring-diesel-cli
+
+[print_schema]
+file = "src/schema.rs"
+custom_type_derives = ["diesel::query_builder::QueryId", "Clone"]
+
+[migrations_directory]
+dir = "/home/cscherr/Documents/code/rust/rs-basic/members/diesel-demo/migrations"

members/diesel-demo/migrations/2024-06-26-135835_create_posts/down.sql

@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+DROP TABLE IF EXISTS `posts`;

members/diesel-demo/migrations/2024-06-26-135835_create_posts/up.sql

@@ -0,0 +1,8 @@
+-- Your SQL goes here
+CREATE TABLE `posts`(
+	`id` INT4 NOT NULL PRIMARY KEY,
+	`title` VARCHAR NOT NULL,
+	`body` TEXT NOT NULL,
+	`published` BOOL NOT NULL
+);
+

members/diesel-demo/src/lib.rs

@@ -0,0 +1,18 @@
+pub mod schema;
+
+use std::env;
+
+use diesel::prelude::*;
+use diesel::sqlite::SqliteConnection;
+
+use dotenvy::dotenv;
+
+use libpt::log::error; // load envars from a `.env` file
+
+pub fn establish_connection() -> anyhow::Result<SqliteConnection> {
+    dotenv()?;
+
+    let database_url = env::var("DATABASE_URL")?;
+    Ok(SqliteConnection::establish(&database_url)
+        .inspect_err(|e| error!("Error connecting to {}:\n{e:#?}", database_url))?)
+}

members/diesel-demo/src/main.rs

@@ -1,3 +1,16 @@
-fn main() {
+use libpt::log::{self, debug};
-    println!("Hello, world!");
+
+use diesel_demo as lib;
+
+fn main() -> anyhow::Result<()> {
+    let _logger = log::Logger::builder()
+        .max_level(log::Level::TRACE)
+        .uptime(true)
+        .build();
+    debug!("logger initialized");
+
+    let conn = lib::establish_connection()?;
+    debug!("db connection established");
+
+    Ok(())
 }

members/diesel-demo/src/schema.rs

@@ -0,0 +1,12 @@
+// @generated automatically by Diesel CLI.
+
+diesel::table! {
+    posts (id) {
+        id -> Int4,             // what the hell is an Int4???? I guess it must
+                                // be a 4 byte integer (u32?), no way it would be a nibble.
+        title -> Varchar,
+        body -> Text,           // What is the difference between Text and Varchar? I know Varchar
+                                // from various DB stuff but idk Text
+        published -> Bool,
+    }
+}