AnalyticDB:Go

Prerequisites

Before you begin, make sure you have:

• Git installed with its path added to the PATH environment variable

• Go installed — see Download and install

• Go MySQL Driver installed:

  1. Download the driver from go-sql-driver/mysql.

  2. Run the following command to install it to $GOPATH:

     go get github.com/go-sql-driver/mysql

Connect to a cluster

The following example opens a connection to your AnalyticDB for MySQL cluster, configures the connection pool, and runs a SHOW TABLES query.

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "time"
)

const (
    // Account used to connect. AnalyticDB for MySQL supports privileged accounts and standard accounts.
    user = "adb_test"
    // Password of the account.
    password = "xxx"
    // IP address of the cluster. Find it on the Cluster Information page in the AnalyticDB for MySQL console.
    host = "127.0.xx.xx"
    // Port used to connect to the cluster.
    port = 3306
    // Name of the database in the cluster.
    database = "database_name"
    // Connection timeout.
    connectTimeout = "10s"
)

func main() {
    // Open the database connection.
    url := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?timeout=%s", user, password, host, port, database, connectTimeout)
    db, err := sql.Open("mysql", url)
    if err != nil {
        panic(err.Error())
    }
    // Maximum number of open connections. Default is 0 (unlimited).
    db.SetMaxOpenConns(2)
    // Maximum number of idle connections.
    db.SetMaxIdleConns(1)
    // Maximum lifetime of a connection (see Usage notes below).
    db.SetConnMaxLifetime(time.Hour)
    defer db.Close()

    rows, err := db.Query("show tables")
    if err != nil {
        panic(err.Error())
    }
    for rows.Next() {
        var tableName string
        err := rows.Scan(&tableName)
        if err != nil {
            panic(err.Error())
        }
        fmt.Println(tableName)
    }
}

Enable server-side prepared statements

Use db.Prepare to create a prepared statement that the server compiles and caches.

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "time"
)

const (
    user           = "adb_test"
    password       = "xxx"
    host           = "127.0.xx.xx"
    port           = 3306
    database       = "database_name"
    connectTimeout = "10s"
)

func main() {
    url := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?timeout=%s", user, password, host, port, database, connectTimeout)
    db, err := sql.Open("mysql", url)
    if err != nil {
        panic(err.Error())
    }
    defer db.Close()

    db.SetMaxOpenConns(2)
    db.SetMaxIdleConns(1)
    db.SetConnMaxLifetime(time.Hour)

    stmt, err := db.Prepare("select * from student where id = ?")
    if err != nil {
        panic(err.Error())
    }
    defer stmt.Close()

    rows, err := stmt.Query(9)
    if err != nil {
        panic(err.Error())
    }
    defer rows.Close()

    for rows.Next() {
        var id, name, unit string
        err := rows.Scan(&id, &name, &unit)
        if err != nil {
            panic(err.Error())
        }
        fmt.Println(fmt.Sprintf("%s, %s, %s", id, name, unit))
    }
}

Enable client-side prepared statements

To use client-side prepared statements, set interpolateParams=true in the connection URL. The driver then interpolates query parameters locally before sending the statement to the server.

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "time"
)

const (
    user           = "adb_test"
    password       = "xxx"
    host           = "127.0.xx.xx"
    port           = 3306
    database       = "database_name"
    connectTimeout = "10s"
)

func main() {
    // Set interpolateParams=true to enable client-side prepared statements.
    url := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?timeout=%s&interpolateParams=true", user, password, host, port, database, connectTimeout)
    db, err := sql.Open("mysql", url)
    if err != nil {
        panic(err.Error())
    }
    defer db.Close()

    db.SetMaxOpenConns(2)
    db.SetMaxIdleConns(1)
    db.SetConnMaxLifetime(time.Hour)

    rows, err := db.Query("select * from student where id = ?", 9)
    if err != nil {
        panic(err.Error())
    }
    defer rows.Close()

    for rows.Next() {
        var id, name, unit string
        err := rows.Scan(&id, &name, &unit)
        if err != nil {
            panic(err.Error())
        }
        fmt.Println(fmt.Sprintf("%s, %s, %s", id, name, unit))
    }
}

Usage notes

What's next

• Learn about connection parameters supported by Go MySQL Driver in the go-sql-driver/mysql documentation.

• Explore AnalyticDB for MySQL SQL syntax to build queries for your application.