从字符串列表中选择数据sql

Question

我想从已定义的字符串列表中选择数据，稍后将根据该列表进行基于某些条件的过滤。

但是，当我想下面的代码：

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 ---- 

它会产生这样的：

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 

，而且我得到的错误是：

异常：'System.Collections.Generic.List`1 [System.String]'附近的语法不正确。

编辑：

预期结果将创建InventoryList表InventoryCode为列名与内部的上述值：

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

然后，会像普通查询：

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 

你预期的SQL查询有两个问题正数。第一个问题是，下面SELECT语句无效

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

你会得到Incorrect syntax near 'a147'错误。它应该包括(和)如下

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

第二个问题，你不能在第二SELECT声明做SELECT从InventoryList如下

SELECT a.[InventoryCode] FROM [InventoryList] a 

因为InventoryList是不是一个真正的表。你会得到Invalid object name 'InventoryList'错误。

你都应该联合声明如下

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 

现在我们要生成使用C＃上面查询的一部分。如果你有inventoryList定义如下

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

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

您可以使用string.Join组合和LINQ选择这样

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

生成以下的输出：('a147'),('w150')，然后使用values变量如下产生预期的SQL查询

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); 

在线演示：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()));