Redis Hash Operations

"Redis hash Operation "

1.hset key field value

　　Sets in the field hash stored on key to value . If key does not exist, a new key holding a hash is created. If field already exists in the hash, it's overwritten.

Return value

Integer reply, specifically:

• 1If is field a new field in the hash and was value set.
• 0If field already exists in the hash and the value is updated.

　　

2.hexists key field

Returns if is a field existing field in the hash stored at key .

Return value

Integer reply, specifically:

• 1If the hash contains field .
• 0If the hash does not contain field , or key does not exist.

　　

3.hget key field

　　Returns the value associated with the field hash stored at key .

Return value

Bulk string reply:the value associated field with, or when was not present in the nil field hash or key does not exist .

　　

4.Hdel key field [field ...]

Removes the specified fields from the hash stored at key . Specified fields and does not exist within this hash is ignored. If key does not exist, it is treated as a empty hash and this command returns 0 .

Return value

The Integer reply:the number of fields this were removed from the hash, not including specified but non existing fields.

5.Hkeys Key

　　Returns all field names in the hash stored key .

Return value

Array reply:list of fields in the hash, or an empty list when key does not exist.

　　

6.hvals Key

Returns all values in the hash stored key .

Return value

Array reply:list of values in the hash, or a empty list when key does not exist.

　　

7.Hgetall Key

Returns all fields and values of the hash stored at key . In the returned value, every field name was followed by it value, so the length of the reply is twice the size of the hash .

Return value

Array reply:list of fields and their values stored in the hash, or a empty list when key does not exist.

　　

8.Hlen Key

　　Returns the number of fields contained in the hash stored at key .

Return value

Integer Reply:number of In the the hash, or 0 when key does not exist.

　　

9.hmset key field value [Field value ...]

Sets the specified fields to their respective values in the hash stored at key . This command overwrites any existing the hash. If key does not exist, a new key holding a hash is created.

Redis Hash Operations