我正在使用Express.js构建一个api。现在,我的第一个睾丸正在工作。现在,我想从两个不同的表中获取值。举例来说,假设我有接下来的2张桌子
Table_A
Id: 1,
Name: Chuck,
Age: 30
Table_B
Id: 1,
NickName: Chuckthulhu,
DateStart: 2018-11-01,
IdTableA: 1
我希望在api上返回的信息是:
{Id: 1, Name: "Chuck", NickName: "Chucthulhu", DateStart: "2018-11-01"}
我该怎么做?到目前为止,这是我的代码:
var express = require("express");
var bodyParser = require("body-parser");
var sql = require("mssql");
var app = express();
app.use(bodyParser.json());
app.use(function (req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT");
res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, contentType,Content-Type, Accept, Authorization");
next();
});
var server = app.listen(process.env.PORT || 8080, function () {
var port = server.address().port;
console.log("App now running on port", port);
});
var dbConfig = {
user: "theUser",
password: "thePassword",
server: "theServer",
database: "theDb"
};
var executeQuery = function(res, query){
sql.connect(dbConfig, function (err) {
if (err) {
console.log(err);
res.send(err);
}
else {
// create Request object
var request = new sql.Request();
// query to the database
request.query(query, function (err, result) {
if (err) {
console.log(err);
res.send(err);
}
else {
res.send(result);
}
});
}
});
}
//GET API
app.get("/api/MyApi", function(req, res){
var query = "select * from [Table_A]";
executeQuery (res, query);
});
我对此很陌生。如我所见,这是获取信息的简单查询...如果这是逻辑,我只需要对Table_B做一个join
或left join
?
我正在使用Javascript,Node和Express.js,以及它在SQL Server上的数据库 谢谢。
答案 0 :(得分:1)
--From your example, IdTableA is the foreign key in Table B which relates it to a record
--in Table A, you would want to Inner Join on that to link it to Table A
--Alias your table''s with a and b and then select the appropriate columns from each
select a.[Id], a.[Name], b.[NickName], b.[DateStart]
from [Table_A] AS a
INNER JOIN [Table_B] AS b
ON b.[IdTableA] = a.[Id]