Memcached incr and decr commands

The Memcached incr and decr commands are used to increment or decrement the numeric value of an existing key.

The data operated by the incr and decr commands must be decimal 32-bit unsigned integers.

If the key does not exist, NOT_FOUND is returned. If the value of the key is not a number, CLIENT_ERROR is returned. For other errors, ERROR is returned.

incr command

Syntax:

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

incr key increment_value

The parameter description is as follows:

• key: The key in the key-value structure is used to find cached values.

• increment_value: Increased value.

Example

In the following example, we use visitors as the key, the initial value is 10, and then add 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: The auto-incremented value is not an object.

• ERROROther errors, such as syntax errors, etc.

decr command

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

decr key decrement_value

The parameter description is as follows:

• key: The key in the key-value structure is used to find cached values.

• decrement_value: Decrement value.

Example

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 the key, the initial value is 10, and then subtracted by 5.

Output

Output information description:

• NOT_FOUND: key does not exist.

• CLIENT_ERROR: The auto-incremented value is not an object.

• ERROROther errors, such as syntax errors, etc.