Sails Waterline SQL加入填充

Waterline是否支持執行SQL連接（除了query()）？我在模型中建立了關聯，但生成的實際SQL查詢是循環選擇語句。目前是否只支持「n + 1選擇」？我在某處丟失配置選項嗎？Sails Waterline SQL加入填充

這裏是一個1->許多填充正在循環選擇語句的一個例子：（帆/水線/帆MySQL的v0.10.0-RC8）

/** 
* City.js 
*/ 
module.exports = { 
"adapter": "someMysqlServer", 
"tableName": "city", 
autoCreatedAt: false, 
autoUpdatedAt: false, 
schema: true, 
attributes: { 
    "id": { 
     "type": "integer", 
     "primaryKey": true, 
     "autoIncrement": true, 
     "columnName": "ID" 
    }, 
    "Name": { 
     "type": "string", 
     "maxLength": 35 
    }, 
    "District": { 
     "type": "string", 
     "maxLength": 20 
    }, 
    "Population": { 
     "type": "integer" 
    }, 
    "CountryCode": { 
     //a city has one country 
     "model": "Country" 
    } 
}}; 




/** 
* Country.js 
*/ 

module.exports = { 
    "adapter": "someMysqlServer", 
    "tableName": "country", 
    autoCreatedAt: false, 
    autoUpdatedAt: false, 
    schema: true, 
    attributes: { 
     "id": { 
      "type": "string", 
      "required": true, 
      columnName: "Code", 
      "primaryKey": true, 
      "maxLength": 3 
     }, 
     "Name": { 
      "type": "string", 
      "maxLength": 52 
     }, 
     Continent: "string", 
     "Region": { 
      "type": "string", 
      "maxLength": 26 
     }, 
     SurfaceArea: "float", 
     IndepYear: "integer", 
     Population: "integer", 
     LifeExpectancy: "float", 
     GNP: "float", 
     GNPOld: "float", 
     LocalName: "string", 
     GovernmentForm: "string", 
     HeadOfState: "string", 
     Capital: "integer", 
     Code2: "string", 
     Cities: { 
      //country has many cities 
      "collection": "City", 
      "via": "CountryCode" 
     } 
    } 
};

然後，當我導航到http://localhost:1337/country?populate=[Cities]我日誌顯示以下SQL被執行：

SELECT `country`.`Name`, `country`.`Continent`, `country`.`Region`, `country`.`SurfaceArea`, `country`.`IndepYear`, `country`.`Population`, `country`.`LifeExpectancy`, `country`.`GNP`, `country`.`GNPOld`, `country`.`LocalName`, `country`.`GovernmentForm`, `country`.`HeadOfState`, `country`.`Capital`, `country`.`Code2`,`country`.`Code` FROM `country` LIMIT 30 OFFSET 0 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ABW' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='AFG' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='AGO' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='AIA' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ALB' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='AND' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ANT' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ARE' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ARG' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ARM' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ASM' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ATA' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ATF' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='ATG' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='AUS' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='AUT' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='AZE' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BDI' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BEL' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BEN' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BFA' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BGD' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BGR' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BHR' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BHS' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BIH' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BLR' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BLZ' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BMU' LIMIT 30 
SELECT `city`.`Name`, `city`.`CountryCode`, `city`.`District`, `city`.`Population`, `city`.`ID` FROM `city` WHERE `city`.`CountryCode`='BOL' LIMIT 30

來源

2014-07-14 jaredfromsubway

我遇到同樣的問題。測試我是否使用？populate = [model] url我得到相同的行爲。如果我明確調用Model.find（）。populate（'OtherModel'），我會得到一個稍微更優化的版本（使用IN），但仍然沒有連接。 – Rowan

在測試的.populate()實施故意簡化支持儘可能廣泛的組適配器。在最後的v0.10發行版中，受支持的「核心」SQL適配器（sails-mysql和sails-postgresql）將執行實際的連接。

來源

2014-07-26 22:54:40 sgress454

@ sgress454對此有何更新？我只是安裝了帆0.10.2和sails-mysql 0.10.4和mysql日誌顯示以下輸出：'（SELECT * FROM city AS city WHERE CountryCode =「ABW」ORDER BY city.id ASC LIMIT 30）UNION（SELECT * FROM ASC LIMIT 30）（...） – jaredfromsubway

這是因爲你正在擊中默認限制爲30條記錄的藍圖路線。在這種情況下，你不能做簡單的連接，因爲查詢只返回30行，你真正想要的是最多900行（30個國家，每個都有30個城市）。因此，'UNION'比仍然爲每個國家進行單獨的查詢要好得多。如果您可以將其歸結爲單個查詢，那麼我們對查看它非常感興趣！有關更多信息，請參見[本文]（http://www.xaprb.com/blog/2006/12/07/how-to-select-the-firstleastmax-row-per-group-in-sql/）問題。 – sgress454

Sails Waterline SQL加入填充

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