C# 逐字字符串文本中的替换？

关于如何在C#中编写长SQL查询，解决方案建议将长SQL查询编写为：

string query = @"
    SELECT
        c.CUSTOMER_ID,
        COALESCE (c.FIRST_NAME, ''_ + ' ' + COALESCE (c.LAST_NAME, '') AS FULL_NAME
        ct.NAME as CUSTOMER_TYPE
    FROM
        CT_CUSTOMER_TYPE AS ct INNER JOIN CUSTOMER AS c
            ON ct.CUSTOMER_TYPE_ID = c.CUSTOMER_TYPE_ID
    "; 

---

这让我对另一个相关问题感到好奇。我可以用替代法吗？也就是说，如果表名更改，但查询保持不变，我将如何处理？我必须回到使用字符串连接构建字符串的另一种方法，还是有更优雅的方法

为什么不使用string.Format？在您给出的具体示例中，您可以执行以下操作

string query = @"
SELECT
    c.CUSTOMER_ID,
    COALESCE (c.FIRST_NAME, ''_ + ' ' + COALESCE (c.LAST_NAME, '') AS FULL_NAME
    ct.NAME as CUSTOMER_TYPE
FROM
    {0} AS ct INNER JOIN {1} AS c
        ON ct.CUSTOMER_TYPE_ID = c.CUSTOMER_TYPE_ID
"; 

以及调用

string real_query = string.Format(query, tblName1, tblName2);

---

是的，您可以使用String.Format方法

string custtype = "CT_CUSTOMER_TYPE";
string cust = "CUSTOMER"; 
string query = @"
SELECT
    c.CUSTOMER_ID,
    COALESCE (c.FIRST_NAME, ''_ + ' ' + COALESCE (c.LAST_NAME, '') AS FULL_NAME
    ct.NAME as CUSTOMER_TYPE
FROM
    {0} AS ct INNER JOIN {1} AS c
        ON ct.CUSTOMER_TYPE_ID = c.CUSTOMER_TYPE_ID
"; 

string endQuery = String.Format(query, custtype, cust);

---

String .Frand方法将用{S}顺序的参数替换字符串中的参数，因此{ 0 }将用CuSTType的值替换，{C}的值为1 }。

< P>您可以考虑使用LINQ to SQL，如果还没有的话。 回答实际问题时，如果要创建查询，可以使用前面提到的

string.Format

。如果要修改现有字符串，请尝试使用

string.Replace

或

Regex.Replace

，如前所述。即:

string query = @"
    SELECT
        c.CUSTOMER_ID,
        COALESCE (c.FIRST_NAME, ''_ + ' ' + COALESCE (c.LAST_NAME, '') AS FULL_NAME
        ct.NAME as CUSTOMER_TYPE
    FROM
        CT_CUSTOMER_TYPE AS ct INNER JOIN CUSTOMER AS c
            ON ct.CUSTOMER_TYPE_ID = c.CUSTOMER_TYPE_ID
    ";
query.Replace("CT_CUSTOMER_TYPE", "NEW_TABLE_NAME");

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这是一个很好的回应和想法。