SQL查詢不適用於SQL Server

Question

我是Web服務的新手，已經編寫了一些簡單的查詢。 他們工作得很好，但是這個不返回json

SqlDataReader dr;
SqlCommand cmd = new SqlCommand("SELECT * FROM doctors WHERE address LIKE %@add%", conn);
cmd.Parameters.AddWithValue("@add", address);

dr = cmd.ExecuteReader();

如果我輸入像

"select * from doctors WHERE address = @add

它工作正常

似乎是什么問題？

Answer 1

將％添加到值中，而不是參數名稱中

var address = "%1 main street%";

SqlDataReader dr;
SqlCommand cmd = new SqlCommand("SELECT * FROM doctors WHERE address LIKE @add", conn);
cmd.Parameters.AddWithValue("@add", address);
dr = cmd.ExecuteReader();

Answer 2

嘗試這個

SqlDataReader dr;
SqlCommand cmd = new SqlCommand("SELECT * FROM doctors WHERE address LIKE '%@add%'", conn);
cmd.Parameters.AddWithValue("@add", address);
dr = cmd.ExecuteReader();