Linq 使用 .net 中的“联接”从具有相同名称的 2 个不同表的 2 列中获取数据？

Question

1. This is my method where I emplement the autocomplete-:

public async Task<List<string>> EmailSearch(string filter)
        {
            try
            {
                var x = await _context.tbl_Account.Where(x => x.Email.Contains(filter) && x.IsActive == true).Select(x => x.Email).ToListAsync();
                return x;
            }
            catch(Exception)
            {
                throw;
            }
        }

2. In the above code I was getting the data from one table but now I want data from another table also using "Joins" with Linq for condition like in above code, in .NET Core.

3. The table names are tbl_Account and tbl_Contacts both table have a column which is named as Email (same column name).

-> Thanks in advance...

Answer 1

You create two queries and then union them, since you're just using a string as a result, you should be ok, try something like this...

public async Task<List<string>> EmailSearch(string filter)
    {
        try
        {
            var x = _context.tbl_Account
                    .Where(x => x.Email.Contains(filter) && x.IsActive == true)
                    .Select(x => x.Email);
            var y = _context.tbl_Contacts
                    .Where(x => x.Email.Contains(filter) && x.IsActive == true)
                    .Select(x => x.Email);

            var z = await x.Union(y).ToListAsync()
            return z;
        }
        catch(Exception)
        {
            throw;
        }
    }