Gocassa is a high-level library on top of gocql.
Compared to gocql it provides query building, adds data binding, and provides easy-to-use "recipe" tables for common query use-cases. Unlike cqlc, it does not use code generation.
For docs, see: https://godoc.org/github.com/hailocab/gocassa
Gocassa provides multiple table types with their own unique interfaces:
- a raw CQL table called simply
Table- this lets you do pretty much any query imaginable - and a number of single purpose 'recipe' tables (
Map,Multimap,TimeSeries,MultiTimeSeries), which aims to help the user by having a simplified interface tailored to a given common query use case
package main
import(
"fmt"
"time"
"github.com/hailocab/gocassa"
)
type Sale struct {
Id string
CustomerId string
SellerId string
Price int
Created time.Time
}
func main() {
keySpace, err := gocassa.ConnectToKeySpace("test", []string{"127.0.0.1"}, "", "")
if err != nil {
panic(err)
}
salesTable := keySpace.Table("sale", Sale{}, gocassa.Keys{
PartitionKeys: []string{"Id"},
})
err = salesTable.Set(Sale{
Id: "sale-1",
CustomerId: "customer-1",
SellerId: "seller-1",
Price: 42,
Created: time.Now(),
}).Run()
if err != nil {
panic(err)
}
result := Sale{}
if err := salesTable.Where(gocassa.Eq("Id", "sale-1")).ReadOne(&result).Run(); err != nil {
panic(err)
}
fmt.Println(result)
}MapTable provides only very simple CRUD functionality:
// …
salesTable := keySpace.MapTable("sale", "Id", Sale{})
result := Sale{}
salesTable.Read("sale-1", &result).Run()
}Read, Set, Update, and Delete all happen by "Id".
MultimapTable can list rows filtered by equality of a single field (eg. list sales based on their sellerId):
salesTable := keySpace.MultimapTable("sale", "SellerId", "Id", Sale{})
// …
results := []Sale{}
err := salesTable.List("seller-1", nil, 0, &results).Run()For examples on how to do pagination or Update with this table, refer to the example (linked under code snippet).
TimeSeriesTable provides an interface to list rows within a time interval:
salesTable := keySpace.TimeSeriesTable("sale", "Created", "Id", Sale{}, 24 * time.Hour)
//...
results := []Sale{}
err := salesTable.List(yesterdayTime, todayTime, &results).Run()MultiTimeSeriesTable is like a cross between MultimapTable and TimeSeriesTable. It can list rows within a time interval, and filtered by equality of a single field. The following lists sales in a time interval, by a certain seller:
salesTable := keySpace.MultiTimeSeriesTable("sale", "SellerId", "Created", "Id", Sale{}, 24 * time.Hour)
//...
results := []Sale{}
err := salesTable.List("seller-1", yesterdayTime, todayTime, &results).Run()In case you get the following error:
Column family names shouldn't be more than 48 characters long (got "somelongishtablename_multitimeseries_start_id_24h0m0s")
You can use the TableName options to override the default internal ones:
tbl = tbl.WithOptions(Options{TableName: "somelongishtablename_mts_start_id_24h0m0s"})