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	Command reference

LINSERT

Syntax text Syntax diagram API methods

LINSERT key <BEFORE | AFTER> pivot element

Client:

linsert(
    name: KeyT,
    where: str,
    refvalue: str,
    value: str
) → Union[Awaitable[int], int]

Possible errors

ERR syntax error: ResponseError

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert(
    key: RedisKey,
    before: "BEFORE",
    pivot: string | Buffer | number,
    element: string | Buffer | number,
    callback?: Callback<number>
) → Result<number, Context>

linsert(
    key: RedisKey,
    after: "AFTER",
    pivot: string | Buffer | number,
    element: string | Buffer | number,
    callback?: Callback<number>
) → Result<number, Context>

Possible errors

ERR syntax error: ReplyError

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert(
    key: byte[],
    where: ListPosition,  // can be BEFORE or AFTER
    value: byte[] pivot final byte[]  // the value
) → long  // The length of the list after the insert operation, or -1 when the value pivot was not found

linsert(
    key: String,
    where: ListPosition,  // can be BEFORE or AFTER
    value: String pivot final String  // the value
) → long  // The length of the list after the insert operation, or -1 when the value pivot was not found

linsert(
    key: String,
    where: ListPosition,  // can be BEFORE or AFTER
    pivot: String,  // reference value
    value: String  // the value
) → long  // The length of the list after the insert operation, or -1 when the value pivot was not found

Possible errors

ERR syntax error: JedisDataException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert(
    key: K,  // the key.
    before: boolean,  // the before.
    pivot: V,  // the pivot.
    value: V  // the value.
) → Long  // Long integer-reply the length of the list after the insert operation, or -1 when the value pivot was not found.

Possible errors

ERR syntax error: RedisCommandExecutionException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert(
    key: K,  // the key.
    before: boolean,  // the before.
    pivot: V,  // the pivot.
    value: V  // the value.
) → RedisFuture<Long>  // Long integer-reply the length of the list after the insert operation, or -1 when the value pivot was not found.

Possible errors

ERR syntax error: RedisCommandExecutionException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert(
    key: K,  // the key.
    before: boolean,  // the before.
    pivot: V,  // the pivot.
    value: V  // the value.
) → Mono<Long>  // Long integer-reply the length of the list after the insert operation, or -1 when the value pivot was not found.

Possible errors

ERR syntax error: RedisCommandExecutionException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

LInsert(
    ctx: context.Context,
    key: Any,
    op: string,
    pivot: Any,
    value: interface{}
) → *IntCmd

Possible errors

ERR syntax error: redis.Error

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

ListInsertAfter(
    key: RedisKey,  // The key of the list.
    pivot: RedisValue,  // The value to insert after.
    value: RedisValue,  // The value to insert.
    flags: CommandFlags  // The flags to use for this operation.
) → long  // The length of the list after the insert operation, or -1 when the value pivot was not found.

ListInsertBefore(
    key: RedisKey,  // The key of the list.
    pivot: RedisValue,  // The value to insert before.
    value: RedisValue,  // The value to insert.
    flags: CommandFlags  // The flags to use for this operation.
) → long  // The length of the list after the insert operation, or -1 when the value pivot was not found.

Possible errors

ERR syntax error: RedisServerException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

ListInsertAfterAsync(
    key: RedisKey,  // The key of the list.
    pivot: RedisValue,  // The value to insert after.
    value: RedisValue,  // The value to insert.
    flags: CommandFlags  // The flags to use for this operation.
) → Task<long>  // The length of the list after the insert operation, or -1 when the value pivot was not found.

ListInsertBeforeAsync(
    key: RedisKey,  // The key of the list.
    pivot: RedisValue,  // The value to insert before.
    value: RedisValue,  // The value to insert.
    flags: CommandFlags  // The flags to use for this operation.
) → Task<long>  // The length of the list after the insert operation, or -1 when the value pivot was not found.

Possible errors

ERR syntax error: RedisServerException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert(
    $key: string,
    $whence: mixed,
    $pivot: mixed,
    $value: mixed
) → int

Possible errors

ERR syntax error: Predis\Response\ServerException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert(
    key: String,
    where: String, Symbol,  // BEFORE or AFTER
    pivot: String,  // reference element
    value: String
) → Integer  // length of the list after the insert operation, or -1 when the element pivot was not found

Possible errors

ERR syntax error: Redis::CommandError

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert_before(
    key: K,
    pivot: P,
    value: V
) → (isize)

linsert_after(
    key: K,
    pivot: P,
    value: V
) → (isize)

Possible errors

ERR syntax error: ErrorKind::Server(ServerErrorKind::ResponseError)

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

linsert_before(
    key: K,
    pivot: P,
    value: V
) → (isize)

linsert_after(
    key: K,
    pivot: P,
    value: V
) → (isize)

Possible errors

ERR syntax error: ErrorKind::Server(ServerErrorKind::ResponseError)

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

Available since:: Redis Open Source 2.2.0
Time complexity:: O(N) where N is the number of elements to traverse before seeing the value pivot. This means that inserting somewhere on the left end on the list (head) can be considered O(1) and inserting somewhere on the right end (tail) is O(N).
ACL categories:: @write, @list, @slow,
Compatibility:: Redis Software and Redis Cloud compatibility

Inserts element in the list stored at key either before or after the reference value pivot.

When key does not exist, it is considered an empty list and no operation is performed.

An error is returned when key exists but does not hold a list value.

Required arguments

key

The name of the key that holds the list.

BEFORE | AFTER

Whether to insert element before or after pivot.

pivot

The existing element to insert relative to.

element

The value to insert.

Examples

redis> RPUSH mylist "Hello"
(integer) 1
redis> RPUSH mylist "World"
(integer) 2
redis> LINSERT mylist BEFORE "World" "There"
(integer) 3
redis> LRANGE mylist 0 -1
1) "Hello"
2) "There"
3) "World"

Redis Software and Redis Cloud compatibility

Redis Software	Redis Cloud	Notes
✅ Standard ✅ Active-Active	✅ Standard ✅ Active-Active

Return information

RESP2 RESP3

One of the following:

Integer reply: the list length after a successful insert operation.
Integer reply: 0 when the key doesn't exist.
Integer reply: -1 when the pivot wasn't found.