Remove TLS from install guide

docs/develop/rust/database/my_sql_driver.md

@@ -8,7 +8,7 @@ The database connection is necessary for today's enterprise development. WasmEdg
 
 <!-- prettier-ignore -->
 :::note
-Before we start, ensure [you have Rust and WasmEdge installed](../setup.md). If you are connecting to a remote MySQL database using TLS, you will need to [install the TLS plugin](../../../start/install.md#tls-plug-in) for WasmEdge as well.
+Before we start, ensure [you have Rust and WasmEdge installed](../setup.md).
 :::
 
 ## Run the example
@@ -20,28 +20,196 @@ git clone https://github.com/WasmEdge/wasmedge-db-examples
 cd wasmedge-db-examples/mysql_async
 
 # Compile the rust code into WASM
-cargo build --target wasm32-wasi --release
+RUSTFLAGS="--cfg wasmedge --cfg tokio_unstable" cargo build --target wasm32-wasi --release
 
 # Execute MySQL statements against a MySQL database at mysql://user:[email protected]:3306
 wasmedge --env "DATABASE_URL=mysql://user:[email protected]:3306/mysql" target/wasm32-wasi/release/crud.wasm
 ```
 
-To use TLS, you will need to turn on the `default-rustls` feature in `Cargo.toml`.
-
-```toml
-mysql_async_wasi = { version = "0.31", features = [ "default-rustls" ] }
-```
-
+To use TLS, you will need to turn on the `default-rustls` feature on the `mysql_async` crate in `Cargo.toml`.
 Then, run the application as follows.
 
 ```toml
 # Execute MySQL statements against an AWS RDS database that requires TLS
 wasmedge --env "DATABASE_SSL=1" --env "DATABASE_URL=mysql://user:[email protected]:3306/mysql" crud.wasm
 ```
 
-## Code explanation
+## Configuration
+
+In order to compile the `mysql_async` and `tokio` crates, we will need to apply two patches to add
+WasmEdge-specific socket APIs to those crates. The following example shows that the TLS connection is enabled.
+
+```
+[patch.crates-io]
+tokio = { git = "https://github.com/second-state/wasi_tokio.git", branch = "v1.36.x" }
+socket2 = { git = "https://github.com/second-state/socket2.git", branch = "v0.5.x" }
+
+[dependencies]
+mysql_async = { version = "0.34", default-features=false, features = [ "default-rustls" ], git="https://github.com/blackbeam/mysql_async.git" }
+zstd-sys = "=2.0.9"
+tokio = { version = "1", features = [ "io-util", "fs", "net", "time", "rt", "macros"] }
+```
+
+## Code example
+
+The following code shows how to connect to a MySQL database server, and then insert, update, and delete records using SQL
+statements.
+
+Connect to a MySQL database.
+
+```
+    // Below we create a customized connection pool
+    let opts = Opts::from_url(&*get_url()).unwrap();
+    let mut builder = OptsBuilder::from_opts(opts);
+    if std::env::var("DATABASE_SSL").is_ok() {
+        builder = builder.ssl_opts(SslOpts::default());
+    }
+    // The connection pool will have a min of 5 and max of 10 connections.
+    let constraints = PoolConstraints::new(5, 10).unwrap();
+    let pool_opts = PoolOpts::default().with_constraints(constraints);
+
+    let pool = Pool::new(builder.pool_opts(pool_opts));
+    let mut conn = pool.get_conn().await.unwrap();
+```
+
+Create a table on the connected database.
+
+```
+    // create table if no tables exist
+    let result = r"SHOW TABLES LIKE 'orders';"
+        .with(())
+        .map(&mut conn, |s: String| String::from(s))
+        .await?;
+
+    if result.len() == 0 {
+        // table doesn't exist, create a new one
+        r"CREATE TABLE orders (order_id INT, production_id INT, quantity INT, amount FLOAT, shipping FLOAT, tax FLOAT, shipping_address VARCHAR(20));".ignore(&mut conn).await?;
+        println!("create new table");
+    } else {
+        // delete all data from the table.
+        println!("delete all from orders");
+        r"DELETE FROM orders;".ignore(&mut conn).await?;
+    }
+```
+
+Insert some records into the MySQL database using SQL.
+
+```
+    let orders = vec![
+        Order::new(1, 12, 2, 56.0, 15.0, 2.0, String::from("Mataderos 2312")),
+        Order::new(2, 15, 3, 256.0, 30.0, 16.0, String::from("1234 NW Bobcat")),
+        Order::new(3, 11, 5, 536.0, 50.0, 24.0, String::from("20 Havelock")),
+        Order::new(4, 8, 8, 126.0, 20.0, 12.0, String::from("224 Pandan Loop")),
+        Order::new(5, 24, 1, 46.0, 10.0, 2.0, String::from("No.10 Jalan Besar")),
+    ];
+
+    r"INSERT INTO orders (order_id, production_id, quantity, amount, shipping, tax, shipping_address)
+      VALUES (:order_id, :production_id, :quantity, :amount, :shipping, :tax, :shipping_address)"
+        .with(orders.iter().map(|order| {
+            params! {
+                "order_id" => order.order_id,
+                "production_id" => order.production_id,
+                "quantity" => order.quantity,
+                "amount" => order.amount,
+                "shipping" => order.shipping,
+                "tax" => order.tax,
+                "shipping_address" => &order.shipping_address,
+            }
+        }))
+        .batch(&mut conn)
+        .await?;
+```
+
+Query the database.
+
+```
+    // query data
+    let loaded_orders = "SELECT * FROM orders"
+        .with(())
+        .map(
+            &mut conn,
+            |(order_id, production_id, quantity, amount, shipping, tax, shipping_address)| {
+                Order::new(
+                    order_id,
+                    production_id,
+                    quantity,
+                    amount,
+                    shipping,
+                    tax,
+                    shipping_address,
+                )
+            },
+        )
+        .await?;
+    dbg!(loaded_orders.len());
+    dbg!(loaded_orders);
+```
+
+Delete some records from the database.
+
+```
+    // // delete some data
+    r"DELETE FROM orders WHERE order_id=4;"
+        .ignore(&mut conn)
+        .await?;
+
+    // query data
+    let loaded_orders = "SELECT * FROM orders"
+        .with(())
+        .map(
+            &mut conn,
+            |(order_id, production_id, quantity, amount, shipping, tax, shipping_address)| {
+                Order::new(
+                    order_id,
+                    production_id,
+                    quantity,
+                    amount,
+                    shipping,
+                    tax,
+                    shipping_address,
+                )
+            },
+        )
+        .await?;
+    dbg!(loaded_orders.len());
+    dbg!(loaded_orders);
+```
+
+Update records in the MySQL database.
+
+```
+    // // update some data
+    r"UPDATE orders
+    SET shipping_address = '8366 Elizabeth St.'
+    WHERE order_id = 2;"
+        .ignore(&mut conn)
+        .await?;
+    // query data
+    let loaded_orders = "SELECT * FROM orders"
+        .with(())
+        .map(
+            &mut conn,
+            |(order_id, production_id, quantity, amount, shipping, tax, shipping_address)| {
+                Order::new(
+                    order_id,
+                    production_id,
+                    quantity,
+                    amount,
+                    shipping,
+                    tax,
+                    shipping_address,
+                )
+            },
+        )
+        .await?;
+    dbg!(loaded_orders.len());
+    dbg!(loaded_orders);
+```
+
+Close the database connection.
+
+```
+    drop(conn);
+    pool.disconnect().await.unwrap();
+```
 
-<!-- prettier-ignore -->
-:::info
-Work in Progress
-:::