HKEYS

HKEYS

1. 如果hash表存在且有字段，则返回所有字段名
2. 如果key不存在，则返回一个空列表

Command

$ redis-cli.exe -h 127.0.0.1 -p 6379
127.0.0.1:6379> hset snake name kobe
(integer) 1
127.0.0.1:6379> hset snake number 24
(integer) 1
127.0.0.1:6379> hkeys snake
1) "name"
2) "number"
127.0.0.1:6379> del snake
(integer) 1
127.0.0.1:6379> hkeys snake
(empty list or set)

Code

func Hkeys(c redis.Conn) {
    // If hash table is existing and has field(s), will return the name of all the fields.
    c.Do("HSET", "snake", "name", "kobe")
    c.Do("HSET", "snake", "number", "24")
    fields, err := redis.Strings(c.Do("HKEYS", "snake"))
    if err != nil {
        colorlog.Error(err.Error())
        return
    }
    for i, v := range fields {
        fmt.Println("field", i, "is:", v)
    }
    //  If key doesn't exist, will return an empty list.
    c.Do("DEL", "snake")
    fields, err = redis.Strings(c.Do("HKEYS", "snake"))
    if err != nil {
        colorlog.Error(err.Error())
        return
    }
    fmt.Println("If key doesn't exist, will return an empty list. List's length is:", len(fields))
}

Output

$ go run main.go 
field 0 is: name
field 1 is: number
If key doesn't exist, will return an empty list. List's length is: 0