Question

我正在修改一个C＃应用程序来遍历一堆SQL文件并用相应的表名替换视图名。

例如，一个名为＆＃34; Item＆＃34;的视图应该用名为＆＃34; Item_mst＆＃34;。

的表替换

我有一个应用程序查看的映射文件，以确定要替换的表，如下所示：

VIEWNAME1,TABLENAME1_MST
VIEWNAME2,TABLENAME2_MST

问题是，有很多场景需要寻找，我在下面用一个示例SQL文件对它们进行了描述。

Select 
    i.item <<Matches the Item table but is actually the name of the column, no replace
    ,dbo.item.u_m <<Matches the Item table with DBO., replace
    ,lot <<Matches the lot table but is actually the name of a column, no replace
    ,(Select top 1 cost from itemcost) as Cost <<itemcost is a table, replace
    ,(Select top 1 cost2 from dbo.itemcost) as Cost2 <<matches the itemcost table with dbo., replace
From 
    dbo.item i <<matches the item table with dbo.,replace
    cross join itemlot <<matches the itemlot table, replace

正如您所看到的，有许多不同的场景，我很难编写正则表达式/查找和替换算法来可靠地捕获每个场景。

我正在匹配dbo.tablename并且很容易替换它们，这是我遇到麻烦的剩余场景。是否有任何REGEX专家有任何想法？

以下是代码段：

//Replace all matched views with table names
for (int j = 0; j < viewCount.Count(); j++)
{
    //replace for "."
    curFileText = curFileText.Replace(".", "XXXPERIODXXX");
    curFileText = Regex.Replace(curFileText, "dboXXXPERIODXXX" + ViewTables[0, j] + "XXXPERIODXXX", "dboXXXPERIODXXX" + ViewTables[1, j] + "XXXPERIODXXX", RegexOptions.IgnoreCase);
    curFileText = curFileText.Replace("XXXPERIODXXX", ".");

    //replace for "newline"
    curFileText = curFileText.Replace(System.Environment.NewLine, "XXXNEWLINEXXX");
    curFileText = Regex.Replace(curFileText, ViewTables[0, j] + "XXXNEWLINEXXX", ViewTables[1, j] + "XXXNEWLINEXXX", RegexOptions.IgnoreCase);
    curFileText = curFileText.Replace("XXXNEWLINEXXX", System.Environment.NewLine);

    //Fix .column_mst spots
    curFileText = curFileText.Replace("dbo.", "XXXDBODOTXXX");
    curFileText = curFileText.Replace(".", "XXXDOTXXX");
    curFileText = Regex.Replace(curFileText, "XXXDOTXXX" + ViewTables[1, j], "XXXDOTXXX" + ViewTables[0, j], RegexOptions.IgnoreCase);
    curFileText = curFileText.Replace("XXXDOTXXX", ".");
    curFileText = curFileText.Replace("XXXDBODOTXXX", "dbo.");

    //replace for " "
    curFileText = curFileText.Replace(" ", "XXXSPACEXXX");
    curFileText = Regex.Replace(curFileText, "dbo." + ViewTables[0, j] + "XXXSPACEXXX", "dbo." + ViewTables[1, j] + "XXXSPACEXXX", RegexOptions.IgnoreCase);
    curFileText = curFileText.Replace("XXXSPACEXXX", " ");
}

Answer 1

为什么不向后解决问题？根据您的RDBMS，您可以使用select table_name, view_definition from information_schema.views之类的查询来获取所有视图名称和基础SQL的列表。在某个地方，每个视图的SQL将是一个select ... from <table name>语句，用于仅基于单个表的视图。将这些结果复制到Sublime或Notepad ++中并使用简单的正则表达式（将([\w\W]+)(\s+from\s+)(\S+)([\w\W]+)替换为$3）来导出与其基础表关联的视图名称列表，如下所示：
vSomeView SomeTable vOtherView OtherTable

完成后，再次使用正则表达式生成.Replace链，将^([^ ])( )(\w\W)$替换为.Replace("$1", "$3")。将.Replace链复制/粘贴到您用于执行此迁移的C＃代码中。

寻找C＃Regex模式SQL表的特定解决方案

1 个答案: