godatabend

databend-go

Golang driver for databend cloud

Key features

• Supports native Databend HTTP client-server protocol
• Compatibility with database/sql

Examples

Connecting

Connection can be achieved either via a DSN string with the format https://user:password@host/database?<query_option>=<value> and sql/Open method such as https://username:password@tenant--warehousename.ch.datafusecloud.com/test.

import (
  "database/sql"
  _ "github.com/databendcloud/databend-go"
)

func ConnectDSN() error {
    dsn, cfg, err := getDSN()
    if err != nil {
    log.Fatalf("failed to create DSN from Config: %v, err: %v", cfg, err)
    }
    conn, err := sql.Open("databend", dsn)
    if err != nil {
        return err
    }
    return conn.Ping()
}

Connection Settings

• host - the connect host such as tenant--warehousename.ch.datafusecloud.com that you can get from databend cloud as follows:

• username/password - auth credentials that you can get from databend cloud connect page as above

• database - select the current default database

Execution

Once a connection has been obtained, users can issue sql statements for execution via the Exec method.

    dsn, cfg, err := getDSN()
	if err != nil {
		log.Fatalf("failed to create DSN from Config: %v, err: %v", cfg, err)
	}
	conn, err := sql.Open("databend", dsn)
	if err != nil {
		fmt.Println(err)
	}
	conn.Exec(`DROP TABLE IF EXISTS data`)
	_, err = conn.Exec(`
    CREATE TABLE IF NOT EXISTS  data(
        Col1 TINYINT,
        Col2 VARCHAR 
    ) 
    `)
	if err != nil {
		fmt.Println(err)
	}
	_, err = conn.Exec("INSERT INTO data VALUES (1, 'test-1')")

Querying Row/s

Querying a single row can be achieved using the QueryRow method. This returns a *sql.Row, on which Scan can be invoked with pointers to variables into which the columns should be marshaled.

dsn, cfg, err := getDSN()
	if err != nil {
		log.Fatalf("failed to create DSN from Config: %v, err: %v", cfg, err)
	}
	conn, err := sql.Open("databend", dsn)
	if err != nil {
		fmt.Println(err)
	}
	row := conn.QueryRow("SELECT * FROM data")
	var (
		col1 uint8
		col2 string
	)
	if err := row.Scan(&col1, &col2); err != nil {
		fmt.Println(err)
	}
	fmt.Println(col2)

Iterating multiple rows requires the Query method. This returns a *sql.Rows struct on which Next can be invoked to iterate through the rows. QueryContext equivalent allows passing of a context.

dsn, cfg, err := getDSN()
	if err != nil {
		log.Fatalf("failed to create DSN from Config: %v, err: %v", cfg, err)
	}
	conn, err := sql.Open("databend", dsn)
	if err != nil {
		fmt.Println(err)
	}
	row, err := conn.Query("SELECT * FROM data")
	var (
		col1 uint8
		col2 string
	)
	for row.Next() {
		if err := row.Scan(&col1, &col2); err != nil {
			fmt.Println(err)
		}
		fmt.Println(col2)
	}