Update

Jump to the Code block for a combined complete example.

Setup

The following examples will use the setup and record below to illustrate single record updates in an Aerospike database.

import aerospike

# Define host configuration
config = {
    'hosts': [ ('127.0.0.1', 3000) ]
}
# Establishes a connection to the server
client = aerospike.client(config).connect()

# Creates a key with the namespace "sandbox", set "ufodata", and user key 5001
key = ('sandbox', 'ufodata', 5001)

The record structure:

+------+----------+----------+----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------+
| PK   | occurred | reported | posted   | report                                                                                                                                                                                                                 | location                                                   |
+------+----------+----------+----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------+
| 5001 | 20220531 | 20220601 | 20220601 | MAP('{"shape":["circle", "flash", "disc"], "summary":"Large flying disc flashed in the sky above the student union. Craziest thing I've ever seen!", "city":"Ann Arbor", "state":"Michigan", "duration":"5 minutes"}') | GeoJSON('{"type":"Point","coordinates":[42.2808,83.743]}') |
+------+----------+----------+----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------+

Policies

Create and Update both utilize write policies that can be defined per command. Each client employs an exists action, specified within the write policy, to define the operation semantics when a record already exists. The default is POLICY_EXISTS_IGNORE.

The following variants are available:

Action Type	Description
POLICY_EXISTS_IGNORE	Create if record doesn’t exist, update otherwise.
POLICY_EXISTS_CREATE	Create if record doesn’t exist already.
POLICY_EXISTS_UPDATE	Update only, if record exists.
POLICY_EXISTS_CREATE_OR_REPLACE	Create if record doesn’t exist, replace otherwise.
POLICY_EXISTS_REPLACE	Replace only, if record exists.

The following example sets the policy to update the record, only if it already exists.

# Can use a previously defined write policy or create a new one
update_policy = {'exists': aerospike.POLICY_EXISTS_UPDATE}

Update a record

Update

With the write policy exists action set to POLICY_EXISTS_IGNORE or POLICY_EXISTS_CREATE, new bins can be added to a record and existing bin values can be updated.

The following example updates the posted bin value to 20220602.

# Create bin with new value
newPosted = {"posted": 20220602}

# Update record with new bin value
client.put(key, newPosted, policy=update_policy)

# Close the connection to the server
client.close()

Type specific

Type specific updates can add integers or append/prepend strings to existing integer and string bin values, respectively.

The following example decrements the posted bin value by one.

# Add value to existing bin
client.increment(key, 'posted', -1, policy=update_policy)

# Close the connection to the server
client.close()

Note

Best practice is to apply add and append/prepend operations as part of a command, and not to use the full-record operation variant described above. Refer to Transaction Operations for information on operations and more client examples.

Replace

To replace a record, set the exists action in the write policy to either POLICY_EXISTS_CREATE_OR_REPLACE or POLICY_EXISTS_REPLACE. Refer to the policies section above for more information on setting the policy and the create page for creating a record to replace the existing one.

The following example sets the existing write policy to replace ony if the record already exists.

# Updating the previously defined write policy
update_policy['exists'] = aerospike.POLICY_EXISTS_REPLACE

Note

A replace can have a performance advantage over an update as a replace may not require reading the record from the device. Certain situations such as a stored key or a secondary index on a bin, and more, may still require a read on a replace, eliminating any performance advantage.

Delete a bin

A bin is deleted by setting it to null. Delete the posted bin by setting its value to null.

# Set bin value to null
removeBin = {'posted': aerospike.null()}

# Update record with null bin
client.put(key, removeBin, policy=update_policy)

# Close the connection to the server
client.close()

Note

Updating a bin value to null, when it is the only bin in the record, deletes the record.

Code block

Expand this section for a single code block to read a record

import aerospike

# Define host configuration
config = {
    'hosts': [ ('127.0.0.1', 3000) ]
}
# Establishes a connection to the server
client = aerospike.client(config).connect()

# Creates a key with the namespace "sandbox", set "ufodata", and user key 5001
key = ('sandbox', 'ufodata', 5001)

# Can use a previously defined write policy or create a new one
update_policy = {'exists': aerospike.POLICY_EXISTS_UPDATE}

# Create bin with new value
newPosted = {"posted": 20220602}

# Update record with new bin value
client.put(key, newPosted, policy=update_policy)

# Close the connection to the server
client.close()