結果差異C＃

Question

我有一個MySQL命令象下面這樣：

 
    string listfh = "Select class_id, location_nm, b.ref_desc, c.ref_desc ,a.days From fh_info as a LEFT JOIN (ref_section as b, ref_language as c) ON ((a.section_id=b.cd) and (a.language_id = c.cd)) WHERE year(a.fh_dt) = '2015' And region_id like 'B%' Order by fh_dt desc"; 
    MySqlDataAdapter daFt = new MySqlDataAdapter(listfh, conn); 
    daFt.Fill(dtList); 

結果返回NULL。但是當在Navicat Query中運行相同的命令時，它會返回正確的答案（2行）。什麼不對？

Answer 1

檢查您的connectionString（康涅狄格州）指出您的數據庫中正確和你的表/視圖名稱之前也提到你的數據庫名稱爲建立與像數據庫對象的正確連接：

string listfh = "Select class_id, location_nm, b.ref_desc, c.ref_desc ,a.days From DatabaseName.dbo.fh_info as a LEFT JOIN (DataBaseName.dbo.ref_section as b, DatabaseName.dbo.ref_language as c) ON ((a.section_id=b.cd) and (a.language_id = c.cd)) WHERE year(a.fh_dt) = '2015' And region_id like 'B%' Order by fh_dt desc"; 
    MySqlDataAdapter daFt = new MySqlDataAdapter(listfh, conn); 
    daFt.Fill(dtList);