# Hashids TSQL Generator
Generates TSQL hash encode functions compatible with hashids.org implementations.
A small set of TSQL functions to generate YouTube-like hashes from one or many numbers. Use hashids when you do not want to expose your database ids to the user.
The included hashids-tsql generator creates a custom set of TSQL functions to encode values with your chosen salt and other options.
The SQL functions generated by hashids-tsql can currently encode numbers, but cannot decode them yet.
The command below will generate a set of TSQL encode functions and test objects into the
npm install -g hashids-tsqlhashids-tsql -t test.sql
What is it?
hashids (Hash ID's) creates short, unique, decryptable hashes from unsigned integers.
(NOTE: This is NOT a true cryptographic hash, since it is reversible.)
It was designed for websites to use in URL shortening, tracking stuff, or making pages private (or at least unguessable).
This algorithm tries to satisfy the following requirements:
- Hashes must be unique and decryptable.
- They should be able to contain more than one integer (so you can use them in complex or clustered systems).
- You should be able to specify minimum hash length.
- Hashes should not contain basic English curse words (since they are meant to appear in public places - like the URL).
Instead of showing items as
3, you could show them as
You can choose to store these hashes in the database or encrypt + decrypt on the fly. If storing them in the database,
then hashids-tsql will let you encode hashids in a TSQL stored procedure, trigger or computed column.
All integers need to be greater than or equal to zero.
See hashids.org for more information on this technique.
TSQL does not have function overloading, so the single
encode function that is common in other hashids.org libraries
is instead represented here as a set of
encode functions with slight variations in name and declaration.
The basic forms of
encode for TSQL are:
encode2(int, int) string
encodeSplit(string, string) string
In TSQL, the
encode functions that take 1 or 2 integers will be much more useful than the one that takes a table
because typically, you don't want to construct a table variable just to pass 1 or 2 integers into a function.
There are multiple variations on each basic form, in order to return different int and string types (
encode1A returns a
varchar (ASCII) value.
encode1B accepts a
encode1BA accepts a
and returns a
varchar (and so on).
The SQL Server database project HashidsTsql in this repository contains a full set of pre-generated functions to test with.
The primary use case for a TSQL hashid encoding function can be seen in the
where the table's
encode1 to hash the
Id column once as part of the atomic INSERT of a record.
As a persisted computed column,
HashId can also be indexed.
If every table were to use the same
encode1 function, then any row in any table with
Id = 1 would have the same
encode2 is provided, which takes 2 numbers. So, TableX can call
encode2(1, [Id]) and TableY can
encode2(2, [Id]) and so on...guaranteeing that the hash for each table's [Id] column don't collide.
Two more TSQL encode functions are currently included which create a hashid from a list of numbers in a table or
delimited string. They are
Usage: hashids-tsql [options] [file or directory/ path]Options:-h, --help output usage information-V, --version output the version number-d, --database [name] Database name. [HashidsTsql]-m, --schema [name] Database schema. [hashids]-a, --ascii Generate ASCII/varchar compatible function(s).-b, --bigint Generate BIGINT compatible function(s).-e, --encodeOnly Generate encode function(s) only.-s, --salt [value] Salt. [random]-n, --minHashLength [n] Minimum hash length. -l, --alphabet [value] Alphabet. [a-z,A-Z,1-9,0]-x, --fileExt [value] Extension for output files. [sql]-t, --test Generate test procedureds and tables.
- Find a better way to detect if a directory path is provided than by looking at the last character.
- Replace No-UTF8-BOM-in-templates.txt note with usage of something like "strip-bom" in app.js
- Create all manner of automated tests, primarily to test against other implementations.
- Create TSQL functions for decoding and integrate them into the hashids-tsql generator.