Convert(int,sys.fn_sqlvarbasetostr(hashbytes('md5','1455985476'))) Link
: This generates a 128-bit MD5 hash of the input string, returned as a varbinary value.
: Creating a non-obvious integer ID from a sensitive string.
For the specific input '1455985476' , the MD5 hash is 792106533f84b730c64951a1ea702c78 . Converting the relevant portion of this hex value to a signed 32-bit integer results in: Common Use Cases : This generates a 128-bit MD5 hash of
: Selecting a deterministic but seemingly random subset of rows (e.g., WHERE ABS(HashConvert) % 10 = 0 for a 10% sample).
: Using sys.fn_sqlvarbasetostr is generally discouraged in production code because it is an undocumented internal function. A more standard approach in T-SQL is CONVERT(INT, HashBytes('MD5', '...'), 2) or directly casting the binary to an integer. Converting the relevant portion of this hex value
: Distributing data rows into different "buckets" or shards by hashing a unique ID.
: This attempts to cast that hex string into a 4-byte integer. Because the hash is much larger than an integer, SQL Server typically truncates the value, often resulting in an arithmetic overflow or returning a signed integer based on the last 4 bytes of the hash. The Result : Distributing data rows into different "buckets" or
: This internal (undocumented) function converts the binary hash into its string representation (e.g., '0x792106533f84b730c64951a1ea702c78' ).
