SQL JOIN錯誤在vb.net

我有這樣的SQL字符串：SQL JOIN錯誤在vb.net

Dim sqlQuery As String = "SELECT TOP 1 ID, FName, FoodGroup, Calories, Protein, Carbohydrates, Fat, category.ID" & 
     " FROM food where Protein<='" & txtProt.Text.ToString() & "' and FoodGroup = 4 " & "and category.ID = 1 " & "JOIN foodCategory ON food.ID = foodCategory.Food_ID" & "JOIN category ON foodCategory.Category_ID = category.ID " & "ORDER BY NEWID() "

什麼我想要做的是這樣的：我想從表中「食物」鍵入值「FName參數」到textBox中，其中表「類別」的「ID」字段爲1.

我有3個表格。第一個是餐桌，第二個是桌子類，第三個是食品類。表foodCategory具有從前兩個表到一對多關係的ID。我收到以下錯誤：JOIN附近的語法不正確。我做錯了什麼？

來源

2012-06-12 Pantheo

查詢不正確，聯接已被內FROM子句中，不能在WHERE子句中設置。

來源

2012-06-12 16:19:40 Sebas

非常感謝。我應該看到... – Pantheo

這也可能是您的連接：

... foodCategory.Food_ID" & "JOIN category ...

將評估爲

foodCategory.Food_IDJOIN category

來源

2012-06-12 16:19:29 Widor

嘗試以下查詢

dim sqlQuery As String 
sqlQuery = "SELECT TOP 1 ID, FName, FoodGroup, Calories, Protein, " & _ 
      "Carbohydrates, Fat, category.ID " &_ 
      "FROM food JOIN foodCategory ON " & _ 
      "food.ID = foodCategory.Food_ID JOIN category ON " & _ 
      "foodCategory.Category_ID = category.ID " & _ 
      "where Protein<='" & txtProt.Text.ToString() & "' and " & _ 
      "FoodGroup = 4 and category.ID = 1 " & _ 
      "ORDER BY NEWID() "

而且你應該看看參數爲你的代碼是SQL注入非常脆弱的！

來源

2012-06-12 16:20:45

這個查詢是錯誤的，你不能在where子句中連接表。 –

啊thx，只是看到了錯誤複製和粘貼 –

「和」是沒有必要的。否則代碼工作。感謝關於SQL注入的警告！ – Pantheo

您的加入必須在WHERE子句前：

" FROM food" & " JOIN foodCategory ON food.ID = foodCategory.Food_ID" & "JOIN category ON  foodCategory.Category_ID = category.ID " & " WHERE Protein<='" & txtProt.Text.ToString() & "' and FoodGroup = 4 " & "and category.ID = 1 " & " ORDER BY NEWID() ";

來源

2012-06-12 16:23:26 crassr3cords

SQL JOIN錯誤在vb.net

回答

相關問題