Tablestore:Query data with the Go driver

Prerequisites

• An AccessKey pair with the ots:SQL* permission (required for RAM users).

• A data table and a mapping table. For more information, see DDL operations.

Procedure

go get github.com/aliyun/aliyun-tablestore-go-sql-driver

import (
    "database/sql"
    _ "github.com/aliyun/aliyun-tablestore-go-sql-driver"
)

// Set the Go driver name and the Tablestore data source name.
db, err := sql.Open("ots", "https://access_key_id:access_key_secret@endpoint/instance_name")
if err != nil {
    panic(err)    // Handle the error.
}

rows, err := db.Query("SELECT pk1, col1, col2 FROM test_table WHERE pk1 = ?", 3)
if err != nil {
    panic(err)
}
defer rows.Close()
for rows.Next() {
    var pk1 int64
    var col1 float64
    var col2 string
    if err := rows.Scan(&pk1, &col1, &col2); err != nil {
        panic(err)
    }
    fmt.Println(pk1, col1, col2)
}

stmt, err := db.Prepare("SELECT pk1, col1, col2 FROM test_table WHERE pk1 = ?")
if err != nil {
    panic(err)
}
defer stmt.Close()
rows, err := stmt.Query(3)
if err != nil {
    panic(err)
}
defer rows.Close()
for rows.Next() {
    var pk1 int64
    var col1 float64
    var col2 string
    if err := rows.Scan(&pk1, &col1, &col2); err != nil {
        panic(err)
    }
    fmt.Println(pk1, col1, col2)
}

Complete example

The following example connects to a Tablestore instance and queries all data from test_table:

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/aliyun/aliyun-tablestore-go-sql-driver"
)

func main() {
    db, err := sql.Open("ots", "https://************************:********************************@myinstance.cn-hangzhou.ots.aliyuncs.com/myinstance")
    if err != nil {
        panic(err)
    }
    defer db.Close()

    rows, err := db.Query("SELECT * FROM test_table")
    if err != nil {
        panic(err)
    }
    defer rows.Close()

    columns, _ := rows.Columns()
    for rows.Next() {
        values := make([]interface{}, len(columns))
        pointers := make([]interface{}, len(columns))
        for i := range values {
            pointers[i] = &values[i]
        }
        if err := rows.Scan(pointers...); err != nil {
            panic(err)
        }
        fmt.Println(values...)
    }
}

Configuration options

Configure the Go driver by adding query parameters to the DSN.

https://ak:sk@endpoint/instance?retryTimes=3&requestTimeout=10s

Time-based options use Go duration format, such as 15s and 500ms.

Data type mapping

Tablestore data types map to Go types. A type mismatch causes an error.