Rust

Install

cargo add ceresdb-client

You can get latest version here.

Init Client

At first, we need to init the client.

• New builder for the client, and you must set endpoint and mode:
  • endpoint is a string which is usually like “ip/domain_name:port”.
  • mode is used to define the way to access horaedb server, detail about mode.

let mut builder = Builder::new("ip/domain_name:port", Mode::Direct/Mode::Proxy);

• New and set rpc_config, it can be defined on demand or just use the default value, detail about rpc config:

let rpc_config = RpcConfig {
    thread_num: Some(1),
    default_write_timeout: Duration::from_millis(1000),
    ..Default::default()
};
let builder = builder.rpc_config(rpc_config);

• Set default_database, it will be used if following rpc calling without setting the database in the RpcContext(will be introduced in later):

    let builder = builder.default_database("public");

• Finally, we build client from builder:

    let client = builder.build();

Manage Table

For ease of use, when using gRPC's write interface for writing, if a table does not exist, HoraeDB will automatically create a table based on the first write.

Of course, you can also use create table statement to manage the table more finely (such as adding indexes).

You can use the sql query interface to create or drop table, related setting will be introduced in sql query section.

• Create table:

let create_table_sql = r#"CREATE TABLE IF NOT EXISTS horaedb (
            str_tag string TAG,
            int_tag int32 TAG,
            var_tag varbinary TAG,
            str_field string,
            int_field int32,
            bin_field varbinary,
            t timestamp NOT NULL,
            TIMESTAMP KEY(t)) ENGINE=Analytic with
            (enable_ttl='false')"#;
let req = SqlQueryRequest {
    tables: vec!["horaedb".to_string()],
    sql: create_table_sql.to_string(),
};

let resp = client
    .sql_query(rpc_ctx, &req)
    .await
    .expect("Should succeed to create table");

• Drop table:

let drop_table_sql = "DROP TABLE horaedb";
let req = SqlQueryRequest {
    tables: vec!["horaedb".to_string()],
    sql: drop_table_sql.to_string(),
};

let resp = client
    .sql_query(rpc_ctx, &req)
    .await
    .expect("Should succeed to create table");

Write

We support to write with the time series data model like InfluxDB.

• Build the point first by PointBuilder, the related data structure of tag value and field value in it is defined as Value, detail about Value:

let test_table = "horaedb";
let ts = Local::now().timestamp_millis();
let point = PointBuilder::new(test_table.to_string())
        .timestamp(ts)
        .tag("str_tag".to_string(), Value::String("tag_val".to_string()))
        .tag("int_tag".to_string(), Value::Int32(42))
        .tag(
            "var_tag".to_string(),
            Value::Varbinary(b"tag_bin_val".to_vec()),
        )
        .field(
            "str_field".to_string(),
            Value::String("field_val".to_string()),
        )
        .field("int_field".to_string(), Value::Int32(42))
        .field(
            "bin_field".to_string(),
            Value::Varbinary(b"field_bin_val".to_vec()),
        )
        .build()
        .unwrap();

• Add the point to write request:

let mut write_req = WriteRequest::default();
write_req.add_point(point);

• New rpc_ctx, and it can also be defined on demand or just use the default value, detail about rpc ctx:

• Finally, write to server by client.

let rpc_ctx = RpcContext {
    database: Some("public".to_string()),
    ..Default::default()
};
let resp = client.write(rpc_ctx, &write_req).await.expect("Should success to write");

Sql Query

We support to query data with sql.

• Define related tables and sql in sql query request:

let req = SqlQueryRequest {
    tables: vec![table name 1,...,table name n],
    sql: sql string (e.g. select * from xxx),
};

• Query by client:

let resp = client.sql_query(rpc_ctx, &req).await.expect("Should success to write");

Example

You can find the complete example in the project.