UUIDs (aka GUIDs)

Since UUIDs (Universally Unique Identifiers) are so common in databases, Modern CSV has the ability to add them to cells by using the Fill Selected Cells with UUID/GUID command.

UUIDs are randomish sequences of 32 hex numbers divided into fields by - characters. An example is 7104f0c7-99a0-40e1-b255-b2bd37b74fac. The number of hex values by field is 8, 4, 4, 4, 12.

When calling the Fill Selected Cells with UUID/GUID command, you can decide whether they’re upper or lower case and whether they’re contained in braces or not. The default option is lower-case without braces.

It comes with a global setting called UUID Type. The two options are:

• Random (v4)
• Time-ordered (v7)

The default setting is Random (v4). The differences are described below.

Random (v4)

UUID v4, defined here, is mostly random or pseudorandom. There are two exceptions:

• The first hex character of the 3rd field (i.e. section separated by - characters) is always 4 for version 4.
• The first character of the 4th field is always 8, 9, a, or b since the first two bits are always set to 0b10.

Examples:

23ad175d-41f1-40f2-8a6d-a23c609b658f
df1f0e18-c208-4aaf-ba56-3421935bbaeb
dca56085-bce5-443f-a5d8-4fd224754413
f5e0d3cd-90d1-43cd-8e6e-b39ea39be3ec

Time-ordered (v7)

UUID v7, defined here, is only random in the second half. A time stamp occupies the first two fields. The rest is the same as v4, except the version character is 7 instead of 4. The first field is the Unix epoch time in seconds (i.e. the number of seconds since midnight January 1, 1970 UTC) when the UUID was generated. It’s represented in hexadecimal. The second field is the exact millisecond when the UUID was generated, also in hexadecimal. Examples:

019bf123-cf3c-7bee-8f97-2de7184eca6e
019bf123-cf3c-792a-9e86-32499c3c32ef
019bf123-cf3c-77fb-b6e1-5a4485aa1dc4
019bf123-cf3c-73df-8ab1-b7b3386a53fc

Note that the first two fields are the same because I generated them at the same time.

Bonus

You can easily make new UUIDs by using the middle mouse button to click on an already existing UUID, dragging it, and pressing the + button. It will also preserve the format (case and surrounding braces or any surrounding text). It will not necessarily preserve the UUID version. It will defer to the UUID Type setting.

The Point

The point of UUIDs is to have unique keys that will not clash. It’s theoretically possible for them to clash just as it’s theoretically possible to win the lottery every week for 100 years, but it’s not going to happen. So for databases, UUIDs make for great record IDs. While v7 UUIDs are not quite as random as v4, their time stamp improves database performance because new entries are mostly added to the end instead of inserted somewhere in the middle. UUIDs are available in either the Premium Personal or Premium Business versions of Modern CSV. If you upgrade, you also get:

• Filtering
• Join and split cells, rows, and columns
• Print and export to PDF
• Analysis tools (Premium Business only)
• A whole bunch more