TDengine/docs/examples/rust/nativeexample/examples/query.rs

use taos::*;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let dsn = "taos://localhost:6030";
    let builder = TaosBuilder::from_dsn(dsn)?;

    let taos = builder.build()?;

    // ANCHOR: create_db_and_table
    let db = "power";
    // create database
    taos.exec_many([
        format!("CREATE DATABASE IF NOT EXISTS `{db}`"),
        format!("USE `{db}`"),
    ])
    .await?;
    println!("Create database power successfully.");

    // create super table
    taos.exec_many([
        "CREATE TABLE `meters` (`ts` TIMESTAMP, `current` FLOAT, `voltage` INT, `phase` FLOAT) \
            TAGS (`groupid` INT, `location` BINARY(24))",
    ]).await?;
    println!("Create stable meters successfully.");

    // ANCHOR_END: create_db_and_table

    // ANCHOR: insert_data
    let inserted = taos.exec("INSERT INTO " +
    "power.d1001 USING power.meters TAGS(2,'California.SanFrancisco') " +
    "VALUES " +
    "(NOW + 1a, 10.30000, 219, 0.31000) " +
    "(NOW + 2a, 12.60000, 218, 0.33000) " +
    "(NOW + 3a, 12.30000, 221, 0.31000) " +
    "power.d1002 USING power.meters TAGS(3, 'California.SanFrancisco') " +
    "VALUES " +
    "(NOW + 1a, 10.30000, 218, 0.25000) ").await?;

    println!("inserted: {} rows to power.meters successfully.", inserted);
    // ANCHOR_END: insert_data

    // ANCHOR: query_data
    // query data, make sure the database and table are created before
    let mut result = taos.query("SELECT ts, current, location FROM power.meters limit 100").await?;

    for field in result.fields() {
        println!("got field: {}", field.name());
    }

    let mut rows = result.rows();
    let mut nrows = 0;
    while let Some(row) = rows.try_next().await? {
        for (col, (name, value)) in row.enumerate() {
            println!(
                "[{}] got value in col {} (named `{:>8}`): {}",
                nrows, col, name, value
            );
        }
        nrows += 1;
    }
    // ANCHOR_END: query_data

    // ANCHOR: query_with_req_id
    let result = taos.query_with_req_id("SELECT ts, current, location FROM power.meters limit 1", 1).await?;
    // ANCHOR_END: query_with_req_id
}