Question

我需要像这样加入两个表

var quer = from i in tableB
           join s in tableA on i.Code.Split('-').FirstOrDefault() equals s.Code                       
           select new { i, s };

这是我的疑问。

public static double sum2d(double[][] theSum) {
    double total2 = 0;
    for (int row = 0; row < theSum.length; row++) {
        for (int col = 0; col < theSum[row].length; col++){
            total2 = total2 + theSum[row][col];
        }
    }
    return total2;
}

但这不起作用......

我该怎么做？

Answer 1

var query = from i in tableB
            from s in tableA 
            where i.Code.StartsWith(s.Code)
            select new { i, s };

Answer 2

我会尝试：

var query = TableA.Join(TableB, 
                   a => a.Code.Split('-').FirstOrDefault(),
                   b => b.SiteCode, 
                   (a, b) => new { a = a, b = b });

Answer 3

试试这段代码它会对你有所帮助。但要确保第一个值不能为空。

var quer = from i in tableB
       join s in tableA on i.Code.Split('-')[0] equals s.Code                       
       select new { i, s };

LINQ join和Split to Sql

3 个答案: