golang 数据库 空字段 问题,hive库更新字段数据

代码：

package mainimport (_ "github.com/go-sql-driver/mysql""fmt""database/sql")func main() {d13()fmt.Println("--------------------------")d14()}func d13(){var err errorconnect := "f:f@tcp(192.168.1.0:3306)/lr1"db, err := sql.Open("mysql", connect)if err != nil{fmt.Println("connect mysql failed, address = " + connect, err)} else{sqlContent := "select real_nm, sex, birth, ext from member where tenant=? and mem_id=?"rows, err := db.Query(sqlContent, "ST", "2017")if err != nil{fmt.Println(err)} else{for rows.Next() {var nm stringvar sex stringvar birth stringvar ext stringerr := rows.Scan(&nm, &sex,&birth, &ext) // birth字段在数据库中是空字段if err != nil{fmt.Println("d11 error. ", err)}fmt.Println(nm)fmt.Println(sex)fmt.Println(birth)fmt.Println(ext)}}}}func d14(){var err errorconnect := "f:f@tcp(192.168.1.0:3306)/lr1"db, err := sql.Open("mysql", connect)if err != nil{fmt.Println("connect mysql failed, address = " + connect, err)} else{sqlContent := "select real_nm, sex, birth, ext from member where tenant=? and mem_id=?"rows, err := db.Query(sqlContent, "ST", "2017")if err != nil{fmt.Println(err)} else{for rows.Next() {nm := sql.NullString{String:"", Valid:false}sex := sql.NullString{String:"", Valid:false}birth := sql.NullString{String:"", Valid:false}ext := sql.NullString{String:"", Valid:false}err := rows.Scan(&nm, &sex,&birth, &ext) // birth字段在数据库中是空字段if err != nil{fmt.Println("d12 error. ", err)}fmt.Println(nm.String)fmt.Println(sex.String)fmt.Println(birth.String)fmt.Println(ext.String)}}}}

运行结果截图：

因为数据库的birth字段为空，所以它在给golang的string对象birth赋值时，出错了（golang的 string不能等于nil）所以后续的数据库的ext就没有再赋值给golang的ext对象了， 而是返回error对象

参考路径：