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Raw String Commands

APPEND​

Syntax​

    APPEND key value

If key already exists and is a string, this command appends the value at the end of the string. If key does not exist it is created and set as an empty string.

RESP Reply​

Integer reply: the length of the string after the append operation.

DECR​

Syntax​

    DECR key

Decrements the number stored at key by one. If the key does not exist, it is set to 0 before performing the operation. An error is returned if the key contains a value of the wrong type or contains a string that can not be represented as integer.

RESP Reply​

Integer reply: the value of the key after decrementing it.

DECRBY​

Syntax​

    DECRBY key decrement

Decrements the number stored at key by the value of parameter decrement. If the key does not exist, it is set to 0 before performing the operation. An error is returned if the key contains a value of the wrong type or contains a string that can not be represented as integer.

Resp Reply​

Integer reply: the value of the key after decrementing it.

GET​

Syntax​

    GET key

Gets the value of key. If the key does not exist nil is returned.

Resp Reply​

One of the following:

  • Bulk string reply: the value of the key.
  • Nil reply: if the key does not exist.

GETEX​

Syntax​

    GETEX key [EX seconds | PX milliseconds | EXAT unix-time-seconds | PXAT unix-time-milliseconds | PERSIST]

Get the value of key and optionally set its expiration. GETEX is similar to GET, but is a write command with additional options.

The GETEX command supports a set of options that modify its behavior:

  • EX seconds -- Set the specified expire time, in seconds.
  • PX milliseconds -- Set the specified expire time, in milliseconds.
  • EXAT timestamp-seconds -- Set the specified Unix time at which the key will expire, in seconds.
  • PXAT timestamp-milliseconds -- Set the specified Unix time at which the key will expire, in milliseconds.
  • PERSIST -- Remove the time to live associated with the key.

Resp Reply​

One of the following:

  • Bulk string reply: the value of the key.
  • Nil reply: if the key does not exist or if the key's value type is not a string.

GETDEL​

Syntax​

    GETDEL key

Get the value of key and delete the key. This command is similar to GET, but that it also deletes the key on success (if and only if the key's value type is a string).

Resp Reply​

One of the following:

  • Bulk string reply: the value of the key.
  • Nil reply: if the key does not exist or if the key's value type is not a string.

GETSET​

Note: GETSET is a deprecated command, use SET with the GET argument when migrating or writing new code.

Syntax​

    GETSET key value

Atomically sets key to value and returns the old value stored at key.

Resp Reply​

One of the following:

  • Bulk string reply: the old value stored at the key.
  • Null reply: if the key does not exist.

GETRANGE​

Syntax​

    GETRANGE key start end

Returns the substring of the string value stored at key, determined by the offsets start and end (both are inclusive).

Resp Reply​

Bulk string reply: The substring of the string value stored at key, determined by the offsets start and end (both are inclusive).

SUBSTR​

Note: SUBSTR is a deprecated command, use GETRANGE when migrating or writing new code.

Syntax​

    SUBSTR key start end

Returns the substring of the string value stored at key, determined by the offsets start and end (both are inclusive).

Resp Reply​

Bulk string reply: The substring of the string value stored at key, determined by the offsets start and end (both are inclusive).

INCR​

Syntax​

    INCR key

Increments the number stored at key by one. If the key does not exist, it is set to 0 before performing the operation.

Resp Reply​

Integer reply: the value of the key after the increment.

INCRBY​

Syntax​

    INCRBY key increment

Increments the number stored at key by the value of the parameter increment. If the key does not exist, it is set to 0 before performing the operation.

Resp Reply​

Integer reply: the value of the key after the increment.

INCRBYFLOAT​

Syntax​

    INCRBYFLOAT key increment

Increment the string representing a floating point number stored at key by the specified increment. By using a negative increment value, the result is that the value stored at the key is decremented. If the key does not exist, it is set to 0 before performing the operation.

Resp Reply​

Bulk string reply: the value of the key after the increment.

LCS​

Syntax​

    LCS key1 key2 [LEN] [IDX] [MINMATCHLEN len] [WITHMATCHLEN]

Returns the longest common subsequence of the values stored at key1 and key2.

The LCS command supports a set of options that modify its behavior:

  • LEN -- Return the length of the longest common subsequence.
  • IDX -- Return the match positions of the longest common subsequence.
  • MINMATCHLEN len -- Return only matches of length greater than or equal to len.
  • WITHMATCHLEN -- Return the lengths of matches.

Resp Reply​

One of the following:

  • Bulk string reply: the longest common subsequence of the values stored at key1 and key2.
  • Integer reply: the length of the longest common subsequence (if LEN is specified).
  • Array reply: the match positions of the longest common subsequence (if IDX is specified).

MGET​

Syntax​

    MGET key [key ...]

Returns the values of all specified keys. For every key that does not exist, the special value nil is returned.

MSET​

Syntax​

    MSET key value [key value ...]

Sets the given keys to their respective values. MSET replaces existing values with new values, just as regular SET. See MSETNX if you don't want to overwrite existing values.

Resp Reply​

Array reply: a list of values at the specified keys.

MSETNX​

Syntax​

    MSETNX key value [key value ...]

Sets the given keys to their respective values. MSETNX will not perform any operation at all even if just a single key already exists.

Resp Reply​

One of the following:

  • Integer reply: 0 if no key was set (at least one key already existed).
  • Integer reply: 1 if all the keys were set.

PSETEX​

Syntax​

    PSETEX key milliseconds value

PSETEX works exactly like SETEX with the sole difference that the expire time is specified in milliseconds instead of seconds.

Resp Reply​

Simple string reply: OK.

SET​

Syntax​

    SET key value [NX | XX] [GET] [EX seconds | PX milliseconds] [KEEPTTL]

Set key to hold the string value. If key already holds a value, it is overwritten, regardless of its type. Any previous time to live associated with the key is discarded on successful SET operation.

Options:

  • EX seconds -- Set the specified expire time, in seconds (a positive integer).
  • PX milliseconds -- Set the specified expire time, in milliseconds (a positive integer).
  • NX -- Only set the key if it does not already exist.
  • XX -- Only set the key if it already exists.
  • KEEPTTL -- Retain the time to live associated with the key.

Resp Reply​

Any of the following:

  • Nil reply: GET not given: Operation was aborted (conflict with one of the XX/NX options).
  • Simple string reply: OK. GET not given: The key was set.
  • Nil reply: GET given: The key didn't exist before the SET.
  • Bulk string reply: GET given: The previous value of the key.

SETEX​

Syntax​

    SETEX key value

Set key to hold the string value and set key to timeout after a given number of seconds.

Resp Reply​

Simple string reply: OK.

SETNX​

Note: SETNX is a deprecated command, use SET with the NX argument when migrating or writing new code.

Syntax​

    SETNX key value

Set key to hold string value if key does not exist. When key already holds a value, no operation is performed.

Resp Reply​

One of the following:

  • Integer reply: 0 if the key was not set.
  • Integer reply: 1 if the key was set.

STRLEN​

Syntax​

    STRLEN key

Returns the length of the string value stored at key.

Resp Reply​

  • Integer reply: the length of the string stored at key, or 0 when the key does not exist.

SETRANGE​

Syntax​

    SETRANGE key offset value

Overwrites part of the string stored at key, starting at the specified offset, for the entire length of value.

Resp Reply​

  • Integer reply: the length of the string after it was modified by the command.