從字符串列表中選擇數據sql

Question

我想從已定義的字符串列表中選擇數據，稍後將根據該列表進行基於某些條件的過濾。

但是，當我想下面的代碼：

List<string> inventoryList = new List<string>(); 

inventoryList.Add("a147"); 
inventoryList.Add("w150"); 

string.Format("SELECT * FROM (VALUES '{0}') AS InventoryList(InventoryCode)" 
        + " SELECT a.[InventoryCode] FROM [InventoryList] a INNER JOIN [PlayerAccount] b WITH (NOLOCK) ON a.[InventoryCode] = b.[PlayerInventoryCode] WHERE b.[PlayerID] = 146", inventoryList); 

--- Other codes to connect to the database and so on ---- 

它會產生這樣的：

SELECT * FROM (VALUES 'System.Collections.Generic.List`1[System.String]') AS InventoryList(InventoryCode) SELECT a.[InventoryCode] FROM [InventoryList] a INNER JOIN [PlayerAccount] b WITH (NOLOCK) ON a.[InventoryCode] = b.[PlayerInventoryCode] WHERE b.[PlayerID] = 146 

，而且我得到的錯誤是：

異常：'System.Collections.Generic.List`1 [System.String]'附近的語法不正確。

編輯：

預期結果將創建InventoryList表InventoryCode爲列名與內部的上述值：

InventoryList <-- table 
InventoryCode <-- column name 
1. a147 
2. w150 

然後，會像普通查詢：

SELECT a.[InventoryCode] FROM InventoryList a INNER JOIN [PlayerAccount] .... 

Answer 1

下面

SELECT * FROM (VALUES 'a147', 'w150') AS InventoryList(InventoryCode) 
SELECT a.[InventoryCode] FROM [InventoryList] a INNER JOIN [PlayerAccount] b WITH (NOLOCK) ON a.[InventoryCode] = b.[PlayerInventoryCode] WHERE b.[PlayerID] = 146 

你預期的SQL查詢有兩個問題正數。第一個問題是，下面SELECT語句無效

SELECT * FROM (VALUES 'a147', 'w150') AS InventoryList(InventoryCode) 

你會得到Incorrect syntax near 'a147'錯誤。它應該包括(和)如下

SELECT * FROM (VALUES ('a147'), ('w150')) AS InventoryList(InventoryCode) 

第二個問題，你不能在第二SELECT聲明做SELECT從InventoryList如下

SELECT a.[InventoryCode] FROM [InventoryList] a 

因爲InventoryList是不是一個真正的表。你會得到Invalid object name 'InventoryList'錯誤。

你都應該聯合聲明如下

SELECT a.[InventoryCode] 
FROM (SELECT * FROM (VALUES ('a147'), ('w150')) AS InventoryList(InventoryCode)) a 
INNER JOIN [PlayerAccount] b WITH (NOLOCK) 
    ON a.[InventoryCode] = b.[PlayerInventoryCode] 
WHERE b.[PlayerID] = 146 

現在我們要生成使用C＃上面查詢的一部分。如果你有inventoryList定義如下

List<string> inventoryList = new List<string>(); 

inventoryList.Add("a147"); 
inventoryList.Add("w150"); 

您可以使用string.Join組合和LINQ選擇這樣

string values = string.Join(",", inventoryList.Select(x => "('" + x + "')")); 

生成以下的輸出：('a147'),('w150')，然後使用values變量如下產生預期的SQL查詢

string output = string.Format("SELECT a.[InventoryCode] FROM (SELECT * FROM (VALUES {0}) AS InventoryList(InventoryCode)) a INNER JOIN [PlayerAccount] b WITH (NOLOCK) ON a.[InventoryCode] = b.[PlayerInventoryCode] WHERE b.[PlayerID] = 146", values); 

在線演示：https://dotnetfiddle.net/yLKsBv

Answer 2

您需要使用如下的string.format方法。

string.Format("SELECT * FROM (VALUES '{0}','{1}') AS InventoryList" 
           + " SELECT a.[InventoryCode] FROM [InventoryList] a INNER JOIN [PlayerAccount] b WITH (NOLOCK) ON a.[InventoryCode] = b.[PlayerInventoryCode] WHERE b.[PlayerID] = 146", inventoryList[0] , inventoryList[1]); 

你可以使用的string.joinstring.Join("','", inventoryList.ToArray())物品

string.Format("SELECT * FROM (VALUES '{0}') AS InventoryList" 
           + " SELECT a.[InventoryCode] FROM [InventoryList] a INNER JOIN [PlayerAccount] b WITH (NOLOCK) ON a.[InventoryCode] = b.[PlayerInventoryCode] WHERE b.[PlayerID] = 146", string.Join("','", inventoryList.ToArray()));