删除表的最快方法（如果存在）

Question

I am using C# to connect to an access database and checking if a table exists in that database. This is the syntax I am using, but for a few databases that have lots of tables in them it takes quite some time to execute. Is their a faster way to do this as speed is the most important thing for this procedure?

string[] tableNames = new string[4] { "One", "Two", "Three", "Four" };
for (int q = tableNames.GetLowerBound(0); q <= tableNames.GetUpperBound(0); q++)
{
  foreach (DAO.TableDef tabledef in dd.TableDefs)
  {
    string strtable = tableNames[q];
    if (tabledef.Name == strtable) { found = true; }
    if (found) { dd.TableDefs.Delete(strtable); } 
  }
}

For any future travelers who might stumble upon this, this was my final syntax that I used --- Exponentially faster!!!

Last EDIT --- I changed the Execute statement to be encapsulated in a try/catch block as if the table name that is listed in the array does not actually exist it will throw an error.

System.Data.OleDb.OleDbConnection oleconn = new   OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + PathToDatabase" + ".mdb;");
oleconn.Open();
string[] tableNames = new string[4] { "One", "Two", "Three", "Four" };
for (int q = tableNames.GetLowerBound(0); q <= tableNames.GetUpperBound(0); q++)
{
  System.Data.OleDb.OleDbCommand cmd = new OleDbCommand("DROP TABLE " + tableNames[q], oleconn);
  try { cmd.ExecuteNonQuery(); }
  catch {}
}
oleconn.Close();

Answer 1

Reverse the loops (pseudo code):

foreach (DAO.TableDef tabledef in dd.TableDefs)
{
  if (tabledef.Name in tablearray )
  { 
    dd.TableDefs.Delete(strtable); 
  } 
}

Answer 2

I think instead of checking in C# application run following query with your ado.net.

IF OBJECT_ID (N'mytablename', N'U') IS NOT NULL 
     DROP TABLE 'mytablename'

Because it will load meta data when you use ado.net instead of that execute simple query with execute non query.

Answer 3

You can use Drop Table for deleting table.. and its syntax is

   if exists (select * from login where name = 'prishu' and pass='prishu')
    drop table login

for more information use this link

check this link also