Thema: Delphi Komplexe Abfrage

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Jumpy

Registriert seit: 9. Dez 2010
Ort: Mönchengladbach
1.736 Beiträge
 
Delphi 6 Enterprise
 
#3

AW: Komplexe Abfrage

  Alt 19. Jun 2020, 11:14
Ich versteh den Sinn des Inner Join mit "languages l" nicht.
Such dir die l.lang_id raus wo der l.lang_code='en' ist und pack das direkt deine Joinbedingungen:

SQL-Code:
SELECT c.country_id AS countryId,
       c.country_shortcode AS ISOShort,
       c.country_longcode AS ISOLong,
       25 AS LangId, --nur mal als Beispiel
       cn.cn_name AS countryName,
       rn.reg_name AS regionName,
       sn.srn_name AS subregionName
FROM countries c
     LEFT JOIN country_names cn ON cn.cn_cid = c.country_id AND cn.cn_lang = 25,
     LEFT JOIN region_names rn ON rn.reg_id = c.country_region AND rn.reg_lang = 25,
     LEFT JOIN subregion_names sn ON sn.sr_id = c.country_subregion AND sn.srn_lang = 25
ORDER BY c.country_id;
oder wenn du das wirklich so flexibler halten willst könntest du den INNER JOIN auch tatsächlich wie in der neuen Syntax üblich verwenden:

SQL-Code:
SELECT c.country_id AS countryId,
       c.country_shortcode AS ISOShort,
       c.country_longcode AS ISOLong,
       l.lang_id AS LangId,
       cn.cn_name AS countryName,
       rn.reg_name AS regionName,
       sn.srn_name AS subregionName
FROM countries c
     INNER JOIN languages l on l.lang_code = "en"
     LEFT JOIN country_names cn ON cn.cn_cid = c.country_id AND cn.cn_lang = l.lang_id,
     LEFT JOIN region_names rn ON rn.reg_id = c.country_region AND rn.reg_lang = l.lang_id,
     LEFT JOIN subregion_names sn ON sn.sr_id = c.country_subregion AND sn.srn_lang = l.lang_id
ORDER BY c.country_id;
Ralph
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