UUID Functions

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UUID Functions

Vector implements the following SQL procedures to create, convert, and compare UUIDs:

• UUID_CREATE( )

• UUID_COMPARE(uuid1, uuid2)

• UUID_TO_CHAR(u)

• UUID_FROM_CHAR(c)

UUID_CREATE( ) Function

The UUID_CREATE() function creates a 128 bit UUID:

> createdb uuiddb

> sql uuiddb

* CREATE TABLE uuidtable (u1 BYTE (16), u2 BYTE(16));

* INSERT INTO uuidtable VALUES (UUID_CREATE(), UUID_CREATE());

// Verify the length in byte format

* SELECT LENGTH(u1) FROM uuidtable;

//Length returned equals 16 bytes

UUID_COMPARE(uuid1, uuid2) Function

The UUID_COMPARE(uuid1, uuid2) function returns an integer value:

// Determine if u1 is greater than, less than, or equal to u2

* SELECT UUID_COMPARE(u1, u2) FROM uuidtable;

// u1 > u2

UUID_TO_CHAR(u) Function

The UUID_TO_CHAR(u) function converts a generated UUID into its character representation.

* SELECT UUID_TO_CHAR(u1) FROM uuidtable;

// Verify length of UUID in character format

* SELECT LENGTH(UUID_TO_CHAR(u1)) FROM uuidtable;

//A UUID contains 36 characters

UUID_FROM_CHAR(c) Function

The UUID_FROM_CHAR(c) function converts a UUID from its character representation into byte representation:

// Insert a UUID in character format into a table

//

* CREATE TABLE uuidtochar

SELECT UUID_TO_CHAR(u1) AS c1 FROM uuidtable;

* SELECT c1 FROM uuidtochar;

//
// convert UUID into byte representation
//

* SELECT UUID_FROM_CHAR(c1) FROM uuidtochar;