I have a SQL query for MySQL:
WITH `cte` AS ( ( SELECT 1431655747 AS `n` FROM DUAL ) UNION ALL ( SELECT 1431655733 AS `n` FROM DUAL ) UNION ALL ( SELECT 715827794 AS `n` FROM DUAL ) UNION ALL ( SELECT 715827865 AS `n` FROM DUAL ) UNION ALL ( SELECT 1073741809 AS `n` FROM DUAL ) UNION ALL ( SELECT 1073741759 AS `n` FROM DUAL ) UNION ALL ( SELECT 715827800 AS `n` FROM DUAL ) UNION ALL ( SELECT 1431655693 AS `n` FROM DUAL ) UNION ALL ( SELECT 715827789 AS `n` FROM DUAL ) UNION ALL ( SELECT 715827838 AS `n` FROM DUAL ) UNION ALL ( SELECT 715827823 AS `n` FROM DUAL ) UNION ALL ( SELECT 858993391 AS `n` FROM DUAL )) SELECT `cte`.`n`, `maxmind_country`.`country`.`name_en` FROM `cte` JOIN `maxmind_country`.`ipv4` ON `cte`.`n` BETWEEN `maxmind_country`.`ipv4`.`start_int` AND `maxmind_country`.`ipv4`.`last_int` JOIN `maxmind_country`.`country` ON `maxmind_country`.`country`.`geoname_id` = `maxmind_country`.`ipv4`.`v_geoname_id`;
After conversion to jOOQ DSL:
String ipAlias = "n"; SelectSelectStep<Record1<UInteger>> unionIps = ips .stream() .distinct() .map(value -> DSL.select(DSL.val(value).as(ipAlias))) .reduce((r1, r2) -> (SelectSelectStep<Record1<UInteger>>) r1.unionAll(r2)) .orElse(null); if(unionIps == null) return null; CommonTableExpression<Record1<UInteger>> cte = DSL.name("cte").as(unionIps); Field<UInteger> ipField = cte.field(ipAlias, UInteger.class); return dslContext .with(cte) .select(ipField, COUNTRY.NAME_EN) .from(cte) .join(IPV4).on(ipField.between(IPV4.START_INT, IPV4.LAST_INT)) .join(COUNTRY).on(COUNTRY.GEONAME_ID.eq(IPV4.V_GEONAME_ID)) .fetchMap(ipField, Country.class);
The result is:
+------------+----------------+ | n | name_en | +------------+----------------+ | 1431655747 | Spain | | 1431655733 | Spain | | 715827794 | China | | 715827865 | China | | 1073741809 | United States | | 1073741759 | United States | | 715827800 | China | | 1431655693 | Spain | | 715827789 | China | | 715827838 | China | | 715827823 | China | | 858993391 | United Kingdom | +------------+----------------+ 12 rows in set (0.16 sec)
But the explanation shows that there are redundant UNIONs:
id select_type table partitions type possible_keys key key_len ref rows filtered Extra 1 PRIMARY <derived2> ALL 12 100,00 1 PRIMARY ipv4 ALL ipv4_start_int_UNIQUE,ipv4_last_int_UNIQUE,ipv4_v_geoname_id_fk_idx 325934 11,11 Range checked for each record (index map: 0x7) 1 PRIMARY country eq_ref PRIMARY PRIMARY 4 maxmind_country.ipv4.v_geoname_id 1 100,00 2 DERIVED No tables used 3 UNION No tables used 4 UNION No tables used 5 UNION No tables used 6 UNION No tables used 7 UNION No tables used 8 UNION No tables used 9 UNION No tables used 10 UNION No tables used 11 UNION No tables used 12 UNION No tables used 13 UNION No tables used
I rewrote a SQL using another MySQL syntax - VALUES ROW(1), ROW(2), ROW(n):
WITH `cte` AS ( VALUES ROW(1431655747), ROW(1431655733), ROW(715827794), ROW(715827865), ROW(1073741809), ROW(1073741759), ROW(715827800), ROW(1431655693), ROW(715827789), ROW(715827838), ROW(715827823), ROW(858993391)) SELECT `cte`.`column_0`, `maxmind_country`.`country`.`name_en` FROM `cte` JOIN `maxmind_country`.`ipv4` ON `cte`.`column_0` BETWEEN `maxmind_country`.`ipv4`.`start_int` AND `maxmind_country`.`ipv4`.`last_int` JOIN `maxmind_country`.`country` ON `maxmind_country`.`country`.`geoname_id` = `maxmind_country`.`ipv4`.`v_geoname_id`;
The result is the same:
+------------+----------------+ | column_0 | name_en | +------------+----------------+ | 1431655747 | Spain | | 1431655733 | Spain | | 715827794 | China | | 715827865 | China | | 1073741809 | United States | | 1073741759 | United States | | 715827800 | China | | 1431655693 | Spain | | 715827789 | China | | 715827838 | China | | 715827823 | China | | 858993391 | United Kingdom | +------------+----------------+ 12 rows in set (0.16 sec)
But the query planner does not use UNION:
id select_type table partitions type possible_keys key key_len ref rows filtered Extra 1 PRIMARY <derived2> ALL 12 100,00 1 PRIMARY ipv4 ALL ipv4_start_int_UNIQUE,ipv4_last_int_UNIQUE,ipv4_v_geoname_id_fk_idx 325934 11,11 Range checked for each record (index map: 0x7) 1 PRIMARY country eq_ref PRIMARY PRIMARY 4 maxmind_country.ipv4.v_geoname_id 1 100,00 2 DERIVED No tables used
Question: How to convert the final script to jOOQ DSL? I can't find any way to achieve
WITH `cte` AS (VALUES ROW(1), ROW(2), ROW(n)) ... ?
As of jOOQ version 3.15, there is no way to represent the standard SQL
VALUES
constructor asorg.jooq.Select
. It can only be represented asorg.jooq.Table
, see: https://github.com/jOOQ/jOOQ/issues/5871.Therefore, you cannot yet use the jOOQ DSL to express the fully conforming syntax, but you can use
VALUES
in theFROM
clause:This should produce a plan almost identical to what you would expect. Another solution is to use Pure SQL Template.