Update operators for tables (Python)

Some Data API commands, like Update a row (Python), use update operators to modify rows in a table.

Set

The $set operator sets the value of the specified column to the specified value.

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing table
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
    keyspace="KEYSPACE_NAME",
)
table = database.get_table("TABLE_NAME")

# Update a row
table.update_one(
    {"title": "Hidden Shadows of the Past", "author": "John Anthony"},
    {
        "$set": {"rating": 4.5, "genres": ["Fiction", "Drama"]},
    },
)

Unset

The $unset operator sets the specified column’s value to null or the equivalent empty form, such as [] or {} for map, list, and set types.

Unsetting a column produces a tombstone. Excessive tombstones can impact query performance.

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing table
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
    keyspace="KEYSPACE_NAME",
)
table = database.get_table("TABLE_NAME")

# Update a row
table.update_one(
    {"title": "Hidden Shadows of the Past", "author": "John Anthony"},
    {"$unset": {"genres": ""}},
)

Combine operators

You can use multiple update operators in a single update.

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing table
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
    keyspace="KEYSPACE_NAME",
)
table = database.get_table("TABLE_NAME")

# Update a row
table.update_one(
    {"title": "Hidden Shadows of the Past", "author": "John Anthony"},
    {
        "$set": {"rating": 4.5, "genres": ["Fiction", "Drama"]},
        "$unset": {"borrower": ""},
    },
)

Unsupported operators

$rename isn’t supported. Instead, use alterTable to add and drop columns.
$currentDate isn’t supported.
The array operators $push, $each, $pullAll, $addToSet, $pop, and $position aren’t supported.

Update operators for tables (Python)

Set

Unset

Combine operators

Unsupported operators

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