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| package main
import ( "database/sql" "fmt" _ "github.com/go-sql-driver/mysql" )
type user struct { id int age int name string }
var db *sql.DB
func initDb() (err error) { dsn := "root:yuan1121@tcp(127.0.0.1:3306)/lpyuan?charset=utf8mb4&parseTime=True" db, err = sql.Open("mysql", dsn) if err != nil { fmt.Println("open mysql failed") return err }
err = db.Ping() if err != nil { return err } return nil }
func queryRowDemon() { var u user sqlstr := "select id, name, age from user where id =?" err := db.QueryRow(sqlstr, 2).Scan(&u.id, &u.name, &u.age) if err != nil { fmt.Println("scan failed, err:%v\n", err) return } fmt.Printf("id:%d name:%s age:%d\n", u.id, u.name, u.age) }
func queryMultiRowDaemon() { sqlstr := "select id, name, age from user where id > ?" rows, err := db.Query(sqlstr, 0) if err != nil { fmt.Println("db.Query failed, err:", err) return } defer rows.Close() for rows.Next() { var u user err := rows.Scan(&u.id, &u.name, &u.age) if err != nil { fmt.Println("Scan failed , err:", err) return } fmt.Printf("id:%d name:%s age:%d\n", u.id, u.name, u.age) } }
func insertRowDaemon() { sqlstr := "insert into user(name, age) values (?, ?)" ret, err := db.Exec(sqlstr, "张龙", 26) if err != nil { fmt.Println("Exec failed") return } theId, err := ret.LastInsertId() if err != nil { fmt.Println("get last insterId is failed") return } fmt.Printf("insert success, the id is %d", theId) }
func deleteRowDemo() { sqlStr := "delete from user where id = ?" ret, err := db.Exec(sqlStr, 3) if err != nil { fmt.Printf("delete failed, err:%v\n", err) return } n, err := ret.RowsAffected() if err != nil { fmt.Printf("get RowsAffected failed, err:%v\n", err) return } fmt.Printf("delete success, affected rows:%d\n", n) }
func prepareDemon() { sqlstr := "insert into user(name, age) values(?, ?)" stmt, err := db.Prepare(sqlstr) if err != nil { fmt.Println("Prepare sqlstr failed") return } defer stmt.Close() _, err = stmt.Query("马汉", 23) if err != nil { fmt.Println("stmt.Query failed") return } _, err = stmt.Query("李白", 21) if err != nil { fmt.Println("stmt.Query failed ") return }
var m = map[string]int{ "赵虎":22, "打算的撒":23, "银行":24, } for k, v := range m { stmt.Exec(k, v) } fmt.Println("insert success") }
func transactionDemon(){ tx, err := db.Begin() if err != nil{ if tx != nil{ tx.Rollback() } fmt.Println("begin trans failed, err:", err) return } sqlstr1 := "Update user set age = 30 where id = ?" ret1, err := tx.Exec(sqlstr1, 2) if err != nil{ fmt.Println("Exec sql1 error, err:", err) tx.Rollback() return } affRows1, err := ret1.RowsAffected() if err != nil{ tx.Rollback() fmt.Println("RowsAffected failed") return } sqlstr2 := "Update user set age=40 where id=?" ret2, err := tx.Exec(sqlstr2, 3) if err != nil{ tx.Rollback() fmt.Println("exec sqlstr2 failed, err:", err) return } affRows2, err := ret2.RowsAffected() if err != nil{ tx.Rollback() fmt.Println("RowsAffected failed, err:", err) return } fmt.Printf("affRows1:%d affRows2:%d\n", affRows1, affRows2) if affRows1 == 1 && affRows2 == 1{ fmt.Println("事务提交了。。。") tx.Commit() }else{ tx.Rollback() fmt.Println("事务回滚了~") } fmt.Println("exec trans success") }
func main() { err := initDb() if err != nil { fmt.Println("initDB error!") return } fmt.Println("连接数据库成功") fmt.Println("单行查询:") queryRowDemon() fmt.Println("多行查询:") queryMultiRowDaemon() transactionDemon() }
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