Usage Guide
Connect to ByteHouse
1. Connect with API Key
*For ByteHouse Global/China version, users can create and download credentials from console
*For ByteHouse Volcano Cloud Version, users need to create and download credentials from Volcano Cloud's Account Details page
Create the API Key and save it in the local environment.
Test Connectivity
db, err := sql.Open("bytehouse", "tcp://{HOST}:{PORT}?secure=true&user=bytehouse&password={API_KEY}")
//If user wishes to specify the database in url
db, err := sql.Open("bytehouse", "tcp://{HOST}:{PORT}?secure=true&user=bytehouse&password={API_KEY}&database={DATABASE}")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
Replace the Host:Port and API key placeholders in the dsn below as specified in the ByteHouse doc.
DDL
All DDL queries should be done with db.ExecContext
package main
import (
"context"
"fmt"
"github.com/bytehouse-cloud/driver-go/sdk"
)
func main() {
dsn := fmt.Sprintf("tcp://{HOST}:{PORT}?secure=true&user=bytehouse&password={API_KEY}")
//If user wishes to specify the database in url
dsn := fmt.Sprintf("tcp://{HOST}:{PORT}?secure=true&user=bytehouse&password={API_KEY}&database={DATABASE}")
ctx := context.Background()
g, err := sdk.Open(ctx, dsn)
if err != nil {
panic(err)
}
if err := g.Ping(); err != nil {
panic(err)
}
if qs, err := g.QueryContext(ctx, "CREATE DATABASE my_db"); err != nil || qs.Exception() != nil {
if err != nil {
panic(err)
}
if qs.Exception() != nil {
panic(qs.Exception())
}
}
if qs, err := g.QueryContext(ctx,
`CREATE TABLE my_db.animal
(
dog Int64,
cat Int64
)
ENGINE=CnchMergeTree ORDER BY dog`); err != nil || qs.Exception() != nil {
if err != nil {
panic(err)
}
if qs.Exception() != nil {
panic(qs.Exception())
}
}
}
Data Insertion
You can specify the columns to be inserted, if no column is specified, all columns will be chosen
- with select columns
INSERT INTO sample_table (col1, col2) VALUES
- without selected columns
INSERT INTO sample_table VALUES
Single Row
package main
import (
"context"
"fmt"
"github.com/bytehouse-cloud/driver-go/sdk"
)
func main() {
dsn := fmt.Sprintf("tcp://{HOST}:{PORT}?secure=true&user=bytehouse&password={API_KEY}")
//If user wishes to specify the database in url
dsn := fmt.Sprintf("tcp://{HOST}:{PORT}?secure=true&user=bytehouse&password={API_KEY}&database={DATABASE}")
ctx := context.Background()
g, err := sdk.Open(ctx, dsn)
if err != nil {
panic(err)
}
if err := g.Ping(); err != nil {
panic(err)
}
if err := g.SendInsertQuery(ctx, "INSERT INTO my_db.animal VALUES (1,2), (3,4)"); err != nil {
panic(err)
}
}
Batch insertion
package main
import (
"context"
"database/sql"
"fmt"
"github.com/bytehouse-cloud/driver-go"
"github.com/bytehouse-cloud/driver-go/sdk"
sql2 "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://gateway.aws-ap-southeast-1.bytehouse.cloud:19000?secure=true&user=bytehouse&password=HhPNNvXncU:S82kyc44Il")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
// set the insert block size if needed
ctx := bytehouse.NewQueryContext(context.Background())
batchSize := 1000
if err != ctx.AddQuerySetting(bytehouse.InsertBlockSize, batchSize) {
panic(err)
}
if err = sql2.RunConn(ctx, db, func(conn sdk.Conn) error {
stmt, err := conn.PrepareContext(ctx, "INSERT INTO sample_table VALUES (?, ?)")
if err != nil {
return err
}
for i := 0; i < 1e7; i++ {
if err := stmt.ExecContext(ctx, 1, 2); err != nil {
return err
}
}
return stmt.Close() // Remember to close the stmt! This step is a must for the query to go through!
}); err != nil {
fmt.Printf("error = %v", err)
}
}
Insert from select
You can insert from SELECT statements. Output from select statement with be inserted into your table
package main
import (
"context"
"database/sql"
"fmt"
_ "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
// Note first return value is sql.Result, which can be discarded since it is not implemented in the driver
if _, err := db.ExecContext(ctx, "INSERT INTO sample_table SELECT * FROM sample_table"); err != nil {
fmt.Printf("error = %v", err)
}
}
Insertion from local file
CSV
Following shows how it can be done with csv file format
package main
import (
"context"
"database/sql"
"fmt"
"os"
"github.com/bytehouse-cloud/driver-go/sdk"
_ "github.com/bytehouse-cloud/driver-go/sql"
driverSql "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://gateway.aws-ap-southeast-1.bytehouse.cloud:19000?secure=true&user=bytehouse&password=HhPNNvXncU:S82kyc44Il")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
file, err := os.Open("./testdata/insert.csv") // path to your .csv file
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
if err = driverSql.RunConn(ctx, db, func(conn sdk.Conn) error {
_,e :=conn.InsertFromReader(ctx, "INSERT INTO sample_table FORMAT CSV", file)
return e
}); err != nil {
fmt.Printf("error = %v", err)
}
}
Example CSV Format
Format should not have headers
1,2
1,2
Using custom delimiter for your csv file rather than default ,
Add to query setting map your custom delimiter The setting name is format_csv_delimiter
package main
import (
"context"
"database/sql"
"fmt"
"os"
"github.com/bytehouse-cloud/driver-go/sdk"
_ "github.com/bytehouse-cloud/driver-go/sql"
driverSql "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://gateway.aws-ap-southeast-1.bytehouse.cloud:19000?secure=true&user=bytehouse&password=HhPNNvXncU:S82kyc44Il")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
file, err := os.Open("./testdata/insert_with_pipes.csv")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
if err = driverSql.RunConn(ctx, db, func(conn sdk.Conn) error {
_,e :=conn.InsertFromReader(ctx, "INSERT INTO sample_table FORMAT CSV", file)
return e
}); err != nil {
fmt.Printf("error = %v", err)
}
}
CSVWithNames
Use format if your csv file has column headers. Note that this options simply skip the first line of your CSV We do not
read your CSV column headers and match them to the corresponding row You have to make sure that your CSV column ordering
is the same as that defined in your table
package main
import (
"context"
"database/sql"
"fmt"
"os"
"github.com/bytehouse-cloud/driver-go/sdk"
_ "github.com/bytehouse-cloud/driver-go/sql"
driverSql "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
file, err := os.Open("./testdata/insert_with_names.csv")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
if err = driverSql.RunConn(ctx, db, func(conn sdk.Conn) error {
_,e :=conn.InsertFromReader(ctx, "INSERT INTO sample_table FORMAT CSV", file)
return e
}); err != nil {
fmt.Printf("error = %v", err)
}
}
Example CSVWithNames Format
- Note: contents of the first line doesn't matter as it will be skipped
a, b
1, 2
1, 2
JSON
package main
import (
"context"
"database/sql"
"fmt"
"os"
"github.com/bytehouse-cloud/driver-go/sdk"
_ "github.com/bytehouse-cloud/driver-go/sql"
driverSql "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://gateway.aws-ap-southeast-1.bytehouse.cloud:19000?secure=true&user=bytehouse&password=HhPNNvXncU:S82kyc44Il")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
file, err := os.Open("insert.json")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
if err = driverSql.RunConn(ctx, db, func(conn sdk.Conn) error {
_,e :=conn.InsertFromReader(ctx, "INSERT INTO sample_table FORMAT JSON", file)
return e
}); err != nil {
fmt.Printf("error = %v", err)
}
}
Example JSON Format
- JSON field name must match with your clickhouse table field name
- Example: for data below your table should be of this structure
a Int, b Int
{
"data": [
{
"a": 1,
"b": 2
},
{
"a": 1,
"b": 2
}
]
}
Select
To Golang struct
package main
import (
"context"
"database/sql"
"fmt"
_ "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
// Use your own types here depending on your table
type sample struct {
cat int
dog int
}
ctx := context.Background()
rows, err := db.QueryContext(ctx, "SELECT * FROM sample_table LIMIT 5")
if err != nil {
fmt.Printf("error = %v", err)
return
}
out := make([]sample, 5)
i := 0
for rows.Next() {
if err := rows.Scan(&out[i].dog, &out[i].cat); err != nil {
fmt.Printf("error = %v", err)
}
i++
}
fmt.Println(out)
// Remember to close your rows when you are done! This is a must!
if err := rows.Close(); err != nil {
fmt.Printf("error = %v", err)
}
}
Single Row
If you are selecting just a single row, you can use db.QueryRowContext which is much more convenient!
Make sure that your query only returns one row!
package main
import (
"context"
"database/sql"
"fmt"
_ "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
// Use your own types here depending on your table value
type sample struct {
dog int
cat int
}
sampleData := &sample{}
ctx := context.Background()
row := db.QueryRowContext(ctx, "SELECT * FROM sample_table LIMIT 1")
if err := row.Scan(&sampleData.dog, &sampleData.dog); err != nil {
fmt.Printf("error = %v", err)
return
}
fmt.Printf("%+v\n", sampleData)
}
To local file
- Use this when you want to export your query results into a file
CSV
package main
import (
"context"
"database/sql"
"fmt"
"io"
"os"
"github.com/bytehouse-cloud/driver-go/sdk"
_ "github.com/bytehouse-cloud/driver-go/sql"
driverSql "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
file, err := os.OpenFile("./testdata/select_temp.csv", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
var reader io.Reader
if err = driverSql.RunConn(ctx, db, func(conn sdk.Conn) error {
qr, err := conn.QueryContext(ctx, `
SELECT * FROM
sample_table
`)
if err != nil {
return err
}
defer qr.Close()
reader = qr.ExportToReader("CSV")
return nil
}); err != nil {
fmt.Printf("error = %v", err)
return
}
if _, err = io.Copy(file, reader); err != nil {
fmt.Printf("error = %v", err)
}
}
Output: 1,2 3,4 5,6
JSON
package main
import (
"context"
"database/sql"
"fmt"
"io"
"os"
"github.com/bytehouse-cloud/driver-go/sdk"
_ "github.com/bytehouse-cloud/driver-go/sql"
driverSql "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
file, err := os.OpenFile("./testdata/select_temp.json", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
var reader io.Reader
if err = driverSql.RunConn(ctx, db, func(conn sdk.Conn) error {
qr, err := conn.QueryContext(ctx, "SELECT * FROM sample_table")
if err != nil {
return err
}
defer qr.Close()
reader = qr.ExportToReader("JSON")
return nil
}); err != nil {
fmt.Printf("error = %v", err)
return
}
if _, err = io.Copy(file, reader); err != nil {
fmt.Printf("error = %v", err)
}
}
Output
{
"meta": [
{
"name": "dog",
"type": "UInt32"
},
{
"name": "cat",
"type": "UInt32"
}
],
"data": [
{
"dog": 1,
"cat": 2
},
{
"dog": 3,
"cat": 4
},
{
"dog": 5,
"cat": 6
}
],
"rows": 3
}
VALUES
package main
import (
"context"
"database/sql"
"fmt"
"io"
"os"
"github.com/bytehouse-cloud/driver-go/sdk"
_ "github.com/bytehouse-cloud/driver-go/sql"
driverSql "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
file, err := os.OpenFile("./testdata/select_temp.txt", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
var reader io.Reader
if err = driverSql.RunConn(ctx, db, func(conn sdk.Conn) error {
qr, err := conn.QueryContext(ctx, "SELECT * FROM sample_table")
if err != nil {
return err
}
defer qr.Close()
reader = qr.ExportToReader("VALUES")
return nil
}); err != nil {
fmt.Printf("error = %v", err)
return
}
if _, err = io.Copy(file, reader); err != nil {
fmt.Printf("error = %v", err)
}
}
Output
(1, 2),
(3, 4),
(5, 6)
Query with external tables (local file system)
External tables refer to data you want to reference in your query that is not in your database
External table in file CSV ./test_data/external_table.csv
1,4 2,5 3,6
Code Example
package main
import (
"context"
"database/sql"
"fmt"
"os"
"github.com/bytehouse-cloud/driver-go/driver/lib/data/column"
"github.com/bytehouse-cloud/driver-go/sdk"
sqlDriver "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
// Open file
file, err := os.Open("./testdata/external_table.csv")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer file.Close()
// Run insert query
var qr *sdk.QueryResult
if err = sqlDriver.RunConn(ctx, db, func(conn sdk.Conn) error {
qr, err =
conn.QueryContextWithExternalTableReader(
ctx, // External table name used "fish" must match that in the ExternalTableReader
"SELECT a, b FROM fish", sdk.NewExternalTableReader(
// Table name
"fish",
// File path
file,
// Column names
[]string{"a", "b"},
// Column types
[]column.CHColumnType{column.UINT32, column.UINT32},
// File format
"CSV",
),
)
return err
}); err != nil {
fmt.Printf("error = %v", err)
return
}
defer qr.Close()
out := make([][]interface{}, 0, 5)
for {
rowValues, ok := qr.NextRow()
if !ok {
break
}
out = append(out, rowValues)
}
fmt.Println(out) // [[1 4] [2 5] [3 6]]
}
Query settings
Usage Example
package main
import (
"context"
"database/sql"
"fmt"
"github.com/bytehouse-cloud/driver-go"
_ "github.com/bytehouse-cloud/driver-go/sql"
)
func main() {
db, err := sql.Open("bytehouse", "tcp://?region=<region>&account=<account>&user=<user>&password=<password>")
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer db.Close()
ctx := context.Background()
queryCtx := bytehouse.NewQueryContext(ctx)
if err := queryCtx.AddQuerySetting("Query Setting Name", "Query Setting Value"); err != nil {
fmt.Printf("error = %v",
err)
return
}
if _, err := db.ExecContext(queryCtx, "INSERT INTO sample_table VALUES (?, ?)", 1, 2); err != nil {
fmt.Printf("error = %v", err)
}
}
Multi threading and Connection Pooling
The SQL interface that Go provides uses a connection pool by default. Connection pool configuration can be customized during runtime.
The returned pool is thread safe so it can be used by multiple goroutines at the same time. We only call the sql.Open
once.
You must call the Ping()
method to test for connectivity. sql.Open
does not establish connections until a request is sent.
package main
import (
"context"
"database/sql"
"fmt"
bytehouse "github.com/bytehouse-cloud/driver-go"
_ "github.com/bytehouse-cloud/driver-go/sql" //this is required, otherwise "bytehouse" driver will not be registered
"golang.org/x/sync/errgroup"
"log"
"time"
)
func main() {
host := "<<hostname>>"
port := "<<port>>"
apiToken := "<<YOUR_API_TOKEN>>"
dsn := fmt.Sprintf("tcp://%s:%s?secure=true&user=bytehouse&password=%s", host, port, apiToken)
queryString := "select * from numbers(100)"
pool, err := sql.Open("bytehouse", dsn)
if err != nil {
fmt.Printf("error = %v", err)
return
}
defer pool.Close()
//setup the database configuration here
pool.SetMaxOpenConns(10)
pool.SetConnMaxIdleTime(time.Minute)
pool.SetConnMaxLifetime(time.Minute * 5)
pool.SetMaxIdleConns(10)
threadCount := 10
eg := errgroup.Group{}
for i := 0; i < threadCount; i++ {
i := i
eg.Go(func() error {
threadID := fmt.Sprintf("thread-%v", i)
//we need to create bytehouse.NewQueryContext() to assign a query ID and add query settings
queryCtx := bytehouse.NewQueryContext(context.Background())
//set the query ID here, duplicate query IDs will be rejected
queryCtx.SetQueryID(fmt.Sprintf("my_query_id%v", time.Now().String()))
//add optional query settings
if err := queryCtx.AddQuerySetting("max_block_size", "2000"); err != nil {
log.Fatalf("thread %v failed to add query setting err = %v", threadID, err)
return err
}
//test if the connection is valid
if err := pool.Ping(); err != nil {
log.Fatalf("thread %v failed to ping err = %v", threadID, err)
return err
}
//send the query
rows, err := pool.QueryContext(queryCtx, queryString)
if err != nil {
log.Fatalf("thread %v failed to query err = %v", threadID, err)
return err
}
//we must close the row
defer rows.Close()
var num int64
//iterate and retrieve the query result
for rows.Next() {
if err := rows.Scan(&num); err != nil {
log.Fatalf("thread %v failed to scan row err = %v", threadID, err)
return err
}
fmt.Printf("\nID:%v Value: %v", threadID, num)
}
fmt.Printf("\n%v Done!", threadID)
return nil
})
}
//wait for all threads to finish
if err := eg.Wait(); err != nil {
log.Fatalf("one of the threads have an error:= %v", err)
}
fmt.Println("\nAll threads done!")
}