Memcached incr with decr command

The Memcached incr and decr commands are used to self-increase or subtract the numeric values of existing keys.

The data operated by the incr and decr commands must be a decal 32-bit unsigned integer.

If key does not NOT_FOUND, if the value of the key is not a number, CLIENT_ERROR returns and other errors return ERROR.

The incr command

Grammar:

The basic syntax format of the incr command is as follows:

incr key increment_value

The parameters are described below:

• Key: Key in the key-value structure to find cached values.
• increment_value: The increased value.

Instance

In the following example, we use visitors as key, with an initial value of 10, followed by plus 5.

set visitors 0 900 2
10
STORED
get visitors
VALUE visitors 0 2
10
END
incr visitors 5
15
get visitors
VALUE visitors 0 2
15
END

Output

Output information description:

• NOT_FOUND:key does not exist.
• CLIENT_ERROR: Self-value added is not an object.
• ERROR other errors, such as syntax errors.

Decr command

The basic syntax format of the decr command is as follows:

decr key decrement_value

The parameters are described below:

• Key: Key in the key-value structure to find cached values.
• decrement_value: The decreased value.

Instance

set visitors 0 900 2
10
STORED
get visitors
VALUE visitors 0 2
10
END
decr visitors 5
5
get visitors
VALUE visitors 0 1
5
END

In the following example, we use visitors as key, with an initial value of 10, followed by minus 5.

Output

Output information description:

• NOT_FOUND:key does not exist.
• CLIENT_ERROR: Self-value added is not an object.
• ERROR other errors, such as syntax errors.