homework-jianmu/docs/examples/rust/nativeexample/examples/query.rs

67 lines
1.9 KiB
Rust

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!("DROP DATABASE IF EXISTS `{db}`"),
format!("CREATE DATABASE `{db}`"),
format!("USE `{db}`"),
])
.await?;
// create table
taos.exec_many([
// create super table
"CREATE TABLE `meters` (`ts` TIMESTAMP, `current` FLOAT, `voltage` INT, `phase` FLOAT) \
TAGS (`groupid` INT, `location` BINARY(24))",
]).await?;
// 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", inserted);
// ANCHOR_END: insert_data
// ANCHOR: query_data
let mut result = taos.query("SELECT * FROM power.meters").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 * FROM power.meters", 0).await?;
// ANCHOR_END: query_with_req_id
}