Question

我想通过我的Windows窗体以编程方式检查视图是否存在，如果存在，请删除它。我知道如何在SQL Server中执行此操作但从未在C＃中尝试过此操作。我正在使用这种语法，但无法弄清楚它的exat语法（或者它是否正确）。

using (var command1 = connection.CreateCommand())
{
  command1.CommandText = "If Object_ID('ServerName.dbo.ViewName', 'V') IS NOT NULL DROP VIEW 'ServerName.dbo.ViewName'
}

Answer 1

为什么不查询sys.views目录视图。下面的代码段。

bool exists;
var cmd = new OdbcCommand(
  "select case when exists((select * from sys.views where name ='" + 
  viewName + "')) then 1 else 0 end");
exists = (int)cmd.ExecuteScalar() == 1;

Answer 2

为什么sql命令如果作为来自C＃的命令执行会有什么不同？

以下内容应该有效：

using (var command1 = connection.CreateCommand())
{
  command1.CommandText = "IF EXISTS(select * from INFORMATION_SCHEMA.VIEWS where TABLE_SCHEMA = 'dbo' and TABLE_NAME = 'ViewName') DROP VIEW dbo.ViewName";
  //todo: execute command, etc...
}

Answer 3

只需要执行命令

using (var sqlconnection = new SqlConnection())
{
    using (var command = sqlconnection.CreateCommand())
    {
         command.CommandText = "If Object_ID('ServerName.dbo.ViewName', 'V') IS NOT NULL DROP VIEW 'ServerName.dbo.ViewName'";
         command.ExecuteNonQuery();
     }
 }

检查视图是否存在

3 个答案: