go数据操作-MySQL
1.快速入门
下载依赖
go get -u github.com/go-sql-driver/mysql
使用MySQL驱动
func Open(driverName, dataSourceName string) (*DB, error)
Open打开一个dirverName指定的数据库，dataSourceName指定数据源，一般至少包括数据库文件名和其它连接必要的信息。
import (
"database/sql"
_ "github.com/go-sql-driver/mysql"
)
func main() {
// DSN:Data Source Name
dsn := "user:password@tcp(127.0.0.1:3306)/dbname"
db, err := sql.Open("mysql", dsn)
if err != nil {
panic(err)
}
defer db.Close() // 注意这行代码要写在上面err判断的下面
}SetMaxOpenConns
func (db *DB) SetMaxOpenConns(n int)
SetMaxOpenConns设置与数据库建立连接的最大数目。 如果n大于0且小于最大闲置连接数，会将最大闲置连接数减小到匹配最大开启连接数的限制。 如果n<=0，不会限制最大开启连接数，默认为0（无限制）。
SetMaxIdleConns
func (db *DB) SetMaxIdleConns(n int)
SetMaxIdleConns设置连接池中的最大闲置连接数。 如果n大于最大开启连接数，则新的最大闲置连接数会减小到匹配最大开启连接数的限制。 如果n<=0，不会保留闲置连接。
2.CRUD操作
2.1. Insert操作
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
type Place struct {
Country string `db:"country"`
City string `db:"city"`
TelCode int `db:"telcode"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
r, err := Db.Exec("insert into person(username, sex, email)values(?, ?, ?)", "stu001", "man", "[email protected]")
if err != nil {
fmt.Println("exec failed, ", err)
return
}
id, err := r.LastInsertId()
if err != nil {
fmt.Println("exec failed, ", err)
return
}
fmt.Println("insert succ:", id)
}2.2. Select操作
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
type Place struct {
Country string `db:"country"`
City string `db:"city"`
TelCode int `db:"telcode"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
var person []Person
err := Db.Select(&person, "select user_id, username, sex, email from person where user_id=?", 1)
if err != nil {
fmt.Println("exec failed, ", err)
return
}
fmt.Println("select succ:", person)
}2.3. Update操作
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
type Place struct {
Country string `db:"country"`
City string `db:"city"`
TelCode int `db:"telcode"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
res, err := Db.Exec("update person set username=? where user_id=?", "stu0003", 1)
if err != nil {
fmt.Println("exec failed, ", err)
return
}
row, err := res.RowsAffected()
if err != nil {
fmt.Println("rows failed, ",err)
}
fmt.Println("update succ:",row)
}2.4. Delete操作
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
type Place struct {
Country string `db:"country"`
City string `db:"city"`
TelCode int `db:"telcode"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
/*
_, err := Db.Exec("delete from person where user_id=?", 1)
if err != nil {
fmt.Println("exec failed, ", err)
return
}
*/
res, err := Db.Exec("delete from person where user_id=?", 1)
if err != nil {
fmt.Println("exec failed, ", err)
return
}
row,err := res.RowsAffected()
if err != nil {
fmt.Println("rows failed, ",err)
}
fmt.Println("delete succ: ",row)
}3. MySQL事务
mysql事务特性：
1) 原子性
2) 一致性
3) 隔离性
4) 持久性
golang MySQL事务应用：
1） import (“github.com/jmoiron/sqlx")
2) Db.Begin() 开始事务
3) Db.Commit() 提交事务
4) Db.Rollback() 回滚事务
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
type Place struct {
Country string `db:"country"`
City string `db:"city"`
TelCode int `db:"telcode"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
conn, err := Db.Begin()
if err != nil {
fmt.Println("begin failed :", err)
return
}
r, err := conn.Exec("insert into person(username, sex, email)values(?, ?, ?)", "stu001", "man", "[email protected]")
if err != nil {
fmt.Println("exec failed, ", err)
conn.Rollback()
return
}
id, err := r.LastInsertId()
if err != nil {
fmt.Println("exec failed, ", err)
conn.Rollback()
return
}
fmt.Println("insert succ:", id)
r, err = conn.Exec("insert into person(username, sex, email)values(?, ?, ?)", "stu001", "man", "[email protected]")
if err != nil {
fmt.Println("exec failed, ", err)
conn.Rollback()
return
}
id, err = r.LastInsertId()
if err != nil {
fmt.Println("exec failed, ", err)
conn.Rollback()
return
}
fmt.Println("insert succ:", id)
conn.Commit()
}