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ES6 異步函數(shù)返值問題

Node.js JavaScript

千萬里不及你 2018-08-23 15:37:40

類中一成員函數(shù)功能查詢數(shù)據(jù)并返回結果集class DB 中...... async Query(strSql){ await this._conpool.request() .query(strSql, (err, result) => { console.dir(result.recordset); //已查詢到數(shù)據(jù)在此 return result.recordset; });}調用let db = new DB();db.Query2('select * from sc_Product').then(ret => { console.dir(ret); res.json(ret);});一直得不到正確的數(shù)據(jù)，前面打印看到Query函數(shù)查詢是正確的。請教！

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1 回答

桃花長相依

TA貢獻1860條經(jīng)驗獲得超8個贊

用promise封裝，你這個寫法有點不倫不類，（順便一提 async 是ES7)

Query(strSql)
{????return?new?Promise((resolve,reject)=>{????????this._conpool.request()
????????.query(strSql,?(err,?result)?=>?{????????????if(err){????????????????//出錯
????????????????reject(err);
????????????}else{????????????????console.dir(result.recordset);????//已查詢到數(shù)據(jù)在此
????????????????resolve(result.recordset);
????????????}
????????});
????});
}

調用:

????let?db?=?new?DB();
????db.Query('select?*?from?sc_Product').then(ret?=>?{????
????????console.dir(ret);
????????res.json(ret);
????}).catch(e=>{????????//error
????});

或者

async?function(){????let?db?=?new?DB();????try{????????let?ret?=await?db.Query('select?*?from?sc_Product');????????console.dir(ret);
????????res.json(ret);
????}catch(e){????????//error
????}
}