ObjectRedis

Redis database client object

Used to create and manage Redis database, creation method:

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var db = require("db");
var test = new db.openRedis("redis-server");

inheritance relationship

member properties

onsuberror

Function, query and set the error handling function. When the sub has an error or the network is interrupted, it will be called back. When the callback occurs, all subs of this object will be terminated.

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Function Redis.onsuberror;

member function

command

redis basic command method

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Value Redis.command(String cmd,
    ...args);

Call parameters:

cmd: String, specifies the command to send
args: ..., specify the parameters to be sent

Return results:

Value, returns the result returned by the server

set

Associate the string value value to the key. If the key already holds another value, SET overwrites the old value, regardless of the type.

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Redis.set(Buffer key,
    Buffer value,
    Long ttl = 0);

Call parameters:

key:Buffer, specify the key to be associated
value:Buffer, specify the data to be associated
ttl: Long, set the survival time for the key in milliseconds; if ttl is 0, then the survival time is not set

setNX

Set the value of key to value if and only if key does not exist. If the given key already exists, SETNX takes no action.

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Redis.setNX(Buffer key,
    Buffer value,
    Long ttl = 0);

Call parameters:

key:Buffer, specify the key to be associated
value:Buffer, specify the data to be associated
ttl: Long, set the survival time for the key in milliseconds; if ttl is 0, then the survival time is not set

setXX

Set the value of key to value, and set the key only if the key already exists.

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Redis.setXX(Buffer key,
    Buffer value,
    Long ttl = 0);

Call parameters:

key:Buffer, specify the key to be associated
value:Buffer, specify the data to be associated
ttl: Long, set the survival time for the key in milliseconds; if ttl is 0, then the survival time is not set

mset

Set one or more key-value pairs at the same time. If a given key already exists, MSET will overwrite the old value with the new value.

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Redis.mset(Object kvs);

Call parameters:

kvs: Object, specifies the key/value object to be set

Set one or more key-value pairs at the same time. If a given key already exists, MSET will overwrite the old value with the new value.

1Redis.mset(...kvs);

Call parameters:

kvs: ..., specify the key/value list to be set

msetNX

Set one or more key-value pairs at the same time if and only if all given keys do not exist

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Redis.msetNX(Object kvs);

Call parameters:

kvs: Object, specifies the key/value object to be set

Set one or more key-value pairs at the same time if and only if all given keys do not exist

1Redis.msetNX(...kvs);

Call parameters:

kvs: ..., specify the key/value list to be set

append

If key already exists and is a string, the append command appends value to the end of key's original value. If key does not exist, append simply sets the given key to value.

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Integer Redis.append(Buffer key,
    Buffer value);

Call parameters:

key:Buffer, specify the key to be appended
value:Buffer, specify the data to be appended

Return results:

Integer, after appending value, the length of the string in key

setRange

Use the value parameter to overwrite the string value stored in the given key, starting from offset offset

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Integer Redis.setRange(Buffer key,
    Integer offset,
    Buffer value);

Call parameters:

key:Buffer, specify the key to be modified
offset: Integer, specifies the modified byte offset
value:Buffer, specify the data to be overwritten

Return results:

Integer, the length of the string after being modified

getRange

Returns the substring of the string value in key. The interception range of the string is determined by the two offsets of start and end (including start and end)

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Buffer Redis.getRange(Buffer key,
    Integer start,
    Integer end);

Call parameters:

key:Buffer, specify the key to be queried
start: Integer, specifies the starting byte offset of the query
end: Integer, specifies the end byte offset of the query

Return results:

Buffer, intercept the substring obtained

strlen

Returns the length of the string value stored in key. When key stores a value other than a string value, an error is returned.

1Integer Redis.strlen(Buffer key);

Call parameters:

key:Buffer, specify the key to be calculated

Return results:

Integer, the length of the string value. When key does not exist, return 0

bitcount

Counts the number of bits set to 1 in the given string

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Integer Redis.bitcount(Buffer key,
    Integer start = 0,
    Integer end = -1);

Call parameters:

key:Buffer, specify the key to be calculated
start: Integer, specifies the starting byte to be calculated, you can use negative values, -1 represents the last byte, and -2 represents the second to last byte, and so on.
end: Integer, specifies the end byte to be calculated, you can use negative values, -1 represents the last byte, and -2 represents the penultimate byte, and so on.

Return results:

Integer, the number of bits set to 1

get

Returns the string value associated with key. If key does not exist, returns the special value Null.

1Buffer Redis.get(Buffer key);

Call parameters:

key:Buffer, specify the key to be associated

Return results:

Buffer, when key does not exist, return Null, otherwise, return the value of key

mget

Returns all (one or more) values for the given key. If a key does not exist in the given key, then this key returns the special value nil.

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NArray Redis.mget(Array keys);

Call parameters:

keys: Array, specifies the key array to be queried

Return results:

NArray, a list containing all values for a given key

Returns all (one or more) values for the given key. If a key does not exist in the given key, then this key returns the special value nil.

1NArray Redis.mget(...keys);

Call parameters:

keys: ..., specify the key list to be queried

Return results:

NArray, a list containing all values for a given key

getset

Sets the value of the given key to value and returns the old value of the key

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Buffer Redis.getset(Buffer key,
    Buffer value);

Call parameters:

key:Buffer, specify the key to be queried and modified.
value:Buffer, specify the modified value

Return results:

Buffer, returns the old value of the given key

decr

Subtract the decrement from the value stored in key

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Long Redis.decr(Buffer key,
    Long num = 1);

Call parameters:

key:Buffer, specify the key to be modified
num: Long, specifies the value to be subtracted

Return results:

Long, after subtracting num, the value of key

incr

Add the increment to the value stored in key

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Long Redis.incr(Buffer key,
    Long num = 1);

Call parameters:

key:Buffer, specify the key to be modified
num: Long, specifies the value to be added

Return results:

Long, after adding num, the value of key

setBit

For the string value stored in key, set or clear the bit at the specified offset.

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Integer Redis.setBit(Buffer key,
    Integer offset,
    Integer value);

Call parameters:

key:Buffer, specify the key to be modified
offset: Integer, specifies the modified bit offset
value: Integer, specifies the parameter to be set or cleared, which can be 0 or 1

Return results:

Integer, specifies the bit where the offset was originally stored

getBit

For the string value stored in key, obtain the bit at the specified offset

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Integer Redis.getBit(Buffer key,
    Integer offset);

Call parameters:

key:Buffer, specify the key to be queried
offset: Integer, specifies the bit offset of the query

Return results:

Integer, the string value specifies the bit at the offset

exists

Check if the given key exists

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Boolean Redis.exists(Buffer key);

Call parameters:

key:Buffer, specify the key to be associated

Return results:

Boolean, if the key exists, return True, otherwise return False

type

Returns the type of value stored in key

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String Redis.type(Buffer key);

Call parameters:

key:Buffer, specify the key to be queried

Return results:

String, returns the type of value stored in key. Possible values are none (key does not exist) string (string) list (list) set (set) zset (ordered set)hash(hash table)

keys

Find all keys matching the given pattern

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NArray Redis.keys(String pattern);

Call parameters:

pattern: String, specify query mode

Return results:

NArray, a list of keys matching the given pattern

del

Delete one or more given keys. Non-existing keys will be ignored.

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Integer Redis.del(Array keys);

Call parameters:

keys: Array, specifies the key array to be deleted

Return results:

Integer, the number of deleted keys

Delete one or more given keys. Non-existing keys will be ignored.

1Integer Redis.del(...keys);

Call parameters:

keys: ..., specify the key list to be deleted

Return results:

Integer, the number of deleted keys

expire

Set the lifetime for a given key. When the key expires, it will be automatically deleted.

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Boolean Redis.expire(Buffer key,
    Long ttl);

Call parameters:

key:Buffer, specify the key to be set
ttl: Long, set the survival time for the key in milliseconds

Return results:

Boolean, if the key exists, return True, otherwise return False

ttl

Returns the remaining survival time of the given key

1Long Redis.ttl(Buffer key);

Call parameters:

key:Buffer, specify the key to be queried

Return results:

Long, returns the remaining survival time of the key in milliseconds. When the key does not exist, it returns -2. When the key exists but the remaining survival time is not set, it returns -1.

persist

Remove the lifetime of a given key and convert this key from "volatile" (key with lifetime) to "persistent" (a key without lifetime and never expires)

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Boolean Redis.persist(Buffer key);

Call parameters:

key:Buffer, specify the key to be set

Return results:

Boolean, if the key exists, return True, otherwise return False

rename

Rename key to newkey. When key is the same as newkey, or key does not exist, an error is returned.

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Redis.rename(Buffer key,
    Buffer newkey);

Call parameters:

key:Buffer, specify the key to be renamed
newkey:Buffer, specify the destination key to be renamed

renameNX

If and only if newkey does not exist, rename the key to newkey. When the key does not exist, return an error.

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Boolean Redis.renameNX(Buffer key,
    Buffer newkey);

Call parameters:

key:Buffer, specify the key to be renamed
newkey:Buffer, specify the destination key to be renamed

Return results:

Boolean, when the modification is successful, return True, if newkey already exists, return False

sub

Subscribe to the information of a given channel and automatically call func when a message occurs. func contains two parameters, channel and message in order. The same function on the same channel will only be called back once.

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2Redis.sub(Buffer channel,
    Function func);

Call parameters:

channel:Buffer, specify the subscribed channel name
func: Function, specify the callback function

Subscribe to the information of a given set of channels, and automatically call the corresponding callback function when a message occurs. The same function on the same channel will only be called once.

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Redis.sub(Object map);

Call parameters:

map: Object, specifies the channel mapping relationship, the object attribute name will be used as the channel name, and the value of the attribute will be used as the callback function

unsub

Unsubscribe all callbacks for the given channel

1Redis.unsub(Buffer channel);

Call parameters:

channel:Buffer, specify the channel name to unsubscribe from

The specified callback function to unsubscribe from the given channel

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2Redis.unsub(Buffer channel,
    Function func);

Call parameters:

channel:Buffer, specify the channel name to unsubscribe from
func: Function, specifies the callback function for unsubscription

Unsubscribe all callbacks for a given set of channels

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Redis.unsub(Array channels);

Call parameters:

channels: Array, specifies the channel array to unsubscribe from

Specified callback function to unsubscribe from a given set of channels

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Redis.unsub(Object map);

Call parameters:

map: Object, specifies the channel mapping relationship, the object attribute name will be used as the channel name, and the value of the attribute will be used as the callback function

psub

Subscribe to a group of channel information according to the template, and automatically call func when a message occurs. func contains three parameters, channel, message and pattern in order. The same function in the same template will only be called back once.

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Redis.psub(String pattern,
    Function func);

Call parameters:

pattern: String, specifies the subscribed channel template
func: Function, specify the callback function

Subscribe to the information of a given set of channel templates, and automatically call the corresponding func when a message occurs. The same function on the same channel will only be called back once.

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Redis.psub(Object map);

Call parameters:

map: Object, specifies the channel mapping relationship, the object attribute name will be used as the channel template, and the attribute value will be used as the callback function

unpsub

Unsubscribe all callbacks from the channel of the given template

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Redis.unpsub(String pattern);

Call parameters:

pattern: String, specify the unsubscribe channel template

Specified callback function to unsubscribe from the channel of the given template

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Redis.unpsub(String pattern,
    Function func);

Call parameters:

pattern: String, specify the unsubscribe channel template
func: Function, specifies the callback function for unsubscription

Unsubscribe all callbacks for a set of channels with a given template

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Redis.unpsub(Array patterns);

Call parameters:

patterns: Array, specifies the published channel template array

Specified callback function to unsubscribe from a group of template channels

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Redis.unpsub(Object map);

Call parameters:

map: Object, specifies the channel mapping relationship, the object attribute name will be used as the channel template, and the attribute value will be used as the callback function

pub

Send information message to the specified channel channel

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Integer Redis.pub(Buffer channel,
    Buffer message);

Call parameters:

channel:Buffer, specify the publishing channel
message:Buffer, specify the message to be published

Return results:

Integer, the number of clients receiving this message

getHash

Get the Hash object of the specified key. This object is the client containing the specified key. Only by calling its method will the database be operated.

1RedisHash Redis.getHash(Buffer key);

Call parameters:

key:Buffer, specify the key to be obtained

Return results:

RedisHash, returns a Hash object containing the specified key

getList

Get the List object of the specified key. This object is the client containing the specified key. Only by calling its method will the database be operated.

1RedisList Redis.getList(Buffer key);

Call parameters:

key:Buffer, specify the key to be obtained

Return results:

RedisList, returns a List object containing the specified key

getSet

Get the Set object of the specified key. This object is the client containing the specified key. Only by calling its method will the database be operated.

1RedisSet Redis.getSet(Buffer key);

Call parameters:

key:Buffer, specify the key to be obtained

Return results:

RedisSet, returns a Set object containing the specified key

getSortedSet

Get the SortedSet object of the specified key. This object is the client containing the specified key. Only by calling its method will the database be operated.

1RedisSortedSet Redis.getSortedSet(Buffer key);

Call parameters:

key:Buffer, specify the key to be obtained

Return results:

RedisSortedSet, returns the SortedSet object containing the specified key

dump

Serializes the given key and returns the serialized value. Use the restore command to deserialize this value into a Redis key.

1Buffer Redis.dump(Buffer key);

Call parameters:

key:Buffer, specify the key to be serialized

Return results:

Buffer, returns the value after serialization, if the key does not exist, then returns null

restore

Deserialize the given serialized value and associate it with the given key

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Redis.restore(Buffer key,
    Buffer data,
    Long ttl = 0);

Call parameters:

key:Buffer, specify the key to be deserialized
data:Buffer, specify the data to be deserialized
ttl: Long, set the survival time for the key in milliseconds; if ttl is 0, then the survival time is not set

close

Close the current database connection or transaction

1Redis.close();

toString

Returns the string representation of the object. Generally, "[Native Object]" is returned. The object can be re-implemented according to its own characteristics.

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String Redis.toString();

Return results:

String, returns the string representation of the object

toJSON

Returns a JSON format representation of the object, generally returning a collection of readable properties defined by the object.

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Value Redis.toJSON(String key = "");

Call parameters:

key: String, not used

Return results:

Value, returns a value containing JSON serializable

Development Guide

Basic module

built-in objects

community module

ObjectRedis

inheritance relationship

member properties

onsuberror

member function

command

set

setNX

setXX

mset

msetNX

append

setRange

getRange

strlen

bitcount

get

mget

getset

decr

incr

setBit

getBit

exists

type

keys

del

expire

ttl

persist

rename

renameNX

sub

unsub

psub

unpsub

pub

getHash

getList

getSet

getSortedSet

dump

restore

close

toString

toJSON