Executing queries

You can use this command to execute a random query in the clique. Also see the How to try article which lists alternative ways to query a CHYT clique.

CLI

The yt clickhouse execute command has the following parameters (default values are specified in parentheses):

• query: The query.

• --proxy: The cluster on which the clique will be started, for example. This option can also be specified via the YT_PROXY environment variable (for example, export YT_PROXY=<cluster_name>).

• --alias: The alias under which the clique will be available. This option can also be set via the CHYT_ALIAS environment variable (export CHYT_ALIAS=example).

• --format [TabSeparated]: The ClickHouse format in which to output the result.

• --setting: Enables you to pass a random setting to the query in <key>=<value> format, can be specified several times.

Python API

The following method (some of the parameters are intentionally not mentioned because they are not intended to be used in a usual situation) is available in the yt.clickhouse module:

def execute(
    query,
    alias=None,
    format=None,
    settings=None,
    raw=None,
    client=None):
    pass

Some of the parameters overlap with the command line options. The same is true for them as in the previous section. The function returns a string generator from the result and the strings can be python objects (lists, dictionaries, numbers, and strings) and strings in ordered format.

Let's describe the individual parameters and the differences from starting via the CLI:

• format (None) and raw (False): These options control the type of returned values. If raw = False, the function will turn values into python objects similarly to how the YTsaurus Python API read_table method does it. If raw = True, you have to additionally specify the ClickHouse format. Then the returned value will be a string iterator (str) in ordered format.

• settings ({}): A dict with additional ClickHouse settings for the query.

• client: A client from the YTsaurus cluster in which the query to the clique should be run. The global client is taken by default. You can, for example, pass yt.wrapper.YtClient("<cluster_name>") as the client and thus specify the desired cluster. Learn more in the relevant section of the Python API documentation.