Read

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 data retreival from an Aerospike database.

import (
    "fmt"
    "github.com/aerospike/aerospike-client-go/v6"
)

// Establishes a connection to the server
client, err := aerospike.NewClient("127.0.0.1", 3000)
if err != nil {
    log.Fatal(err)
}
defer client.Close()

// Creates a key with the namespace "sandbox", set "ufodata", and user key 5001
key, err := aerospike.NewKey("sandbox", "ufodata", 5001)
if err != nil {
    log.Fatal(err)
}

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

Instead of using the default read policies, we can set them on a per command basis.

The following example creates a new read policy and sets the socket timeout for the command.

// Create new read policy
policy := aerospike.NewPolicy()
policy.SocketTimeout = 300

Read a record

Record exists

Checking record existence is faster than getting the record because it only needs to look at the primary index.

// Returns true if exists, false if not
exists, err := client.Exists(policy, key)
if err != nil {
    log.Fatal(err)
}

// Do something
fmt.Printf("Exists: %v", exists)

Record metadata only

Read record metadata (generation and expiration information) without reading the bins for a specified key.

// Get record metadata
record, err := client.GetHeader(policy, key)
if err != nil {
    log.Fatal(err)
}

// Do something
fmt.Printf("Record: %v", record)

Whole record

Read the record metadata and all bins for a specified key.

// Get whole record
record, err := client.Get(policy, key)
if err != nil {
    log.Fatal(err)
}

// Do something
fmt.Printf("Record: %v", record.Bins)

Specific bins

Read the record metadata and the report and location bins from the record.

// Get bins 'report' and 'location'
record, err := client.Get(policy, key, "report", "location")
if err != nil {
    log.Fatal(err)
}

// Do something
fmt.Printf("Record: %v", record.Bins)

Code block

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

import (
    "fmt"
    "github.com/aerospike/aerospike-client-go/v6"
)

func main() {
    // Establishes a connection to the server
    client, err := aerospike.NewClient("127.0.0.1", 3000)
    if err != nil {
        log.Fatal(err)
    }
    defer client.Close()

    // Creates a key with the namespace "sandbox", set "ufodata", and user key 5001
    key, err := aerospike.NewKey("sandbox", "ufodata", 5001)
    if err != nil {
        log.Fatal(err)
    }

    // Create new read policy
    policy := aerospike.NewPolicy()
    policy.SocketTimeout = 300

    // Get whole record
    record, err := client.Get(policy, key)
    if err != nil {
        log.Fatal(err)
    }

    // Do something
    fmt.Printf("Record: %v", record.Bins)
}