golang: 把sql結果集以json格式輸出

這是一個建立於 的文章，其中的資訊可能已經有所發展或是發生改變。

代碼出處：http://stackoverflow.com/questions/19991541/dumping-mysql-tables-to-json-with-golang

func getJSON(sqlString string) (string, error) {stmt, err := db.Prepare(sqlString)if err != nil {return nil, err}defer stmt.Close()rows, err := stmt.Query()if err != nil {return nil, err}defer rows.Close()columns, err := rows.Columns()if err != nil {  return "", err}count := len(columns)tableData := make([]map[string]interface{}, 0)values := make([]interface{}, count)valuePtrs := make([]interface{}, count)for rows.Next() {  for i := 0; i < count; i++ {  valuePtrs[i] = &values[i]  }  rows.Scan(valuePtrs...)  entry := make(map[string]interface{})  for i, col := range columns {  var v interface{}  val := values[i]  b, ok := val.([]byte)  if ok {  v = string(b)  } else {  v = val  }  entry[col] = v  }  tableData = append(tableData, entry)}jsonData, err := json.Marshal(tableData)if err != nil {  return "", err}fmt.Println(string(jsonData))return string(jsonData), nil }