docs: go and rust

docs/en/05-develop/01-connect/04-rust.md

@@ -17,7 +17,10 @@ Add dependency to `Cargo.toml`.
 
 ```toml title="Cargo.toml"
 [dependencies]
-libtaos = { version="*", feature=["rest"]}
+[dependencies]
+libtaos = { version="0.4.5-alpha.0", features=["rest"]}
+tokio = { version = "1", features = ["full"]}
+anyhow = "*"
 ```
 
 ## Config
@@ -28,24 +31,21 @@ Run this command in your terminal to save TDengine cloud token as variables:
 <TabItem value="bash" label="Bash">
 
 ```bash
-export TDENGINE_CLOUD_TOKEN="<token>"
-export TDENGINE_CLOUD_URL="<url>"
+export TDENGINE_CLOUD_DSN="<DSN>"
 ```
 
 </TabItem>
 <TabItem value="cmd" label="CMD">
 
 ```bash
-set TDENGINE_CLOUD_TOKEN="<token>"
-set TDENGINE_CLOUD_URL="<url>"
+set TDENGINE_CLOUD_DSN="<DSN>"
 ```
 
 </TabItem>
 <TabItem value="powershell" label="Powershell">
 
 ```powershell
-$env:TDENGINE_CLOUD_TOKEN="<token>"
-$env:TDENGINE_CLOUD_URL="<url>"
+$env:TDENGINE_CLOUD_DSN="<DSN>"
 ```
 
 </TabItem>
@@ -53,8 +53,7 @@ $env:TDENGINE_CLOUD_URL="<url>"
 
 <!-- exclude -->
 :::note
-Replace  <token\> and <url\> with cloud token and URL.
-To obtain the value of cloud token and URL, please log in [TDengine Cloud](https://cloud.tdengine.com) and click "Connector" and then select "Rust".
+Replace  <DSN\> with real TDengine cloud DSN. To obtain the real value, please log in [TDengine Cloud](https://cloud.tdengine.com) and click "Connector" and then select "Rust".
 
 :::
 <!-- exclude-end -->

docs/examples/go/connectexample/main.go

@@ -16,7 +16,7 @@ func main() {
 		return
 	}
 	defer taos.Close()
-	rows, err := taos.Query("select server_version()")
+	rows, err := taos.Query("show databases")
 	if err != nil {
 		fmt.Println(err)
 		return

docs/examples/rust/cloud_example/Cargo.toml

@@ -7,5 +7,6 @@ edition = "2021"
 
 
 [dependencies]
-libtaos = { version="0.4.5-alpha.0", feature=["rest"]}
+libtaos = { version="0.4.5-alpha.0", features=["rest"]}
 tokio = { version = "1", features = ["full"]}
+anyhow = "*"

docs/examples/rust/cloud_example/src/main.rs

+use anyhow::Result;
 use libtaos::*;
 
-fn main() {
-    let token =  std::env::var("TDENGINE_CLOUD_TOKEN").unwrap();
-    let url = std::env::var("TDENGINE_CLOUD_URL").unwrap();
-    let dsn = url + "?token=" + &token;
-    let taos = TaosCfg::from_dsn(dsn)?;
-    println!("connected");
+#[tokio::main]
+async fn main() -> Result<()> {
+    let dsn = std::env::var("TDENGINE_CLOUD_DSN").unwrap();
+    let cfg = TaosCfg::from_dsn(dsn)?;
+    let conn = cfg.connect()?;
+    let _ = conn.query("show databases").await?;
+    println!("Connected");
+    Ok(())
 }
\ No newline at end of file