package main
import (
"database/sql"
"fmt"
_ "github.com/go-sql-driver/mysql"
)
func main() {
// Open database connection
db, err := sql.Open("mysql", "root:root@/wxappzxt.fxxx.com")
if err != nil {
panic(err.Error()) // Just for example purpose. You should use proper error handling instead of panic
}
defer db.Close()
// Execute the query
rows, err := db.Query("SELECT * FROM zxt_user")
if err != nil {
panic(err.Error()) // proper error handling instead of panic in your app
}
// Get column names
columns, err := rows.Columns()
if err != nil {
panic(err.Error()) // proper error handling instead of panic in your app
}
// Make a slice for the values
values := make([]sql.RawBytes, len(columns))
// rows.Scan wants '[]interface{}' as an argument, so we must copy the
// references into such a slice
// See http://code.google.com/p/go-wiki/wiki/InterfaceSlice for details
scanArgs := make([]interface{}, len(values))
for i := range values {
scanArgs[i] = &values[i]
}
// Fetch rows
for rows.Next() {
// get RawBytes from data
err = rows.Scan(scanArgs...)
if err != nil {
panic(err.Error()) // proper error handling instead of panic in your app
}
// Now do something with the data.
// Here we just print each column as a string.
var value string
for i, col := range values {
// Here we can check if the value is nil (NULL value)
if col == nil {
value = "NULL"
} else {
value = string(col)
}
fmt.Println(columns[i], ": ", value)
}
fmt.Println("-----------------------------------")
}
}
分析:
values := make([]sql.RawBytes, len(columns))
//sql.RawBytes实际上是 type RawBytes []byte
//[]byte这里可以与转化成string
values := make([]sql.RawBytes, len(columns))
// rows.Scan wants '[]interface{}' as an argument, so we must copy the
// references into such a slice
// See http://code.google.com/p/go-wiki/wiki/InterfaceSlice for details
scanArgs := make([]interface{}, len(values))
for i := range values {
scanArgs[i] = &values[i]
}
实际上&values[i]赋值的是values的指针,len(columns)已经赋值了长度