Useful SQL commands

Select pairs of enabled dynamic interfaces with the same hostname

SELECT i1.id, s1.id, s1.name, d1.name, s2.id, s2.name, i2.id FROM
    dynamic_interface AS i1
    INNER JOIN `range` AS r1 ON i1.range_id = r1.id
    INNER JOIN domain AS d1 ON r1.domain_id = d1.id
    INNER JOIN system AS s1 ON i1.system_id = s1.id
    INNER JOIN system AS s2
        on CONVERT(s1.name USING utf8) COLLATE utf8_bin =
            CONVERT(s2.name USING utf8) COLLATE utf8_bin AND s1.id < s2.id
    INNER JOIN dynamic_interface AS i2 ON s2.id = i2.system_id
    INNER JOIN `range` AS r2 ON i2.range_id = r2.id
    INNER JOIN domain AS d2 ON r2.domain_id = d2.id
    WHERE d1.id = d2.id AND i1.dhcp_enabled AND i2.dhcp_enabled;