Question

I have a problem. I try to create a database backup of a local database.

When I start the program in VS everything is fine because path to database is less than 128 characters. However, when I publish and install the app, path is more than 128 characters in length and I get that error.

On the Internet I found two solutions:

To use a single quote
To set: SET QUOTED_IDENTIFIER OFF & SET ANSI_NULLS ON

but whichever combination I try, I cannot get it right.

Can anyone tell me how to get it right?

My code:

internal void CreateDbBackup(string DbBackupPath)
{
    SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);

    SqlCommand GetDataFile = new SqlCommand();
    GetDataFile.Connection = con;
    GetDataFile.CommandText = "select physical_name from sys.database_files where type = 0";

    con.Open();
    string YourDataFile = (string)GetDataFile.ExecuteScalar();
    con.Close();

    SqlCommand cmd = con.CreateCommand();
    cmd.CommandText = string.Format(@"BACKUP DATABASE [" + YourDataFile + "] TO  DISK = N'{0}' WITH  INIT ,  NOUNLOAD ,  NOSKIP ,  STATS = 10,  NOFORMAT", DbBackupPath);

    con.Open();
    cmd.ExecuteNonQuery();
    con.Close();
}

Answer 1

当您选择Optional.ofNullable(toCheck) .filter(e -> { int strLen; if (str == null || (strLen = str.length()) == 0) { return true; } for (int i = 0; i < strLen; i++) { if ((Character.isWhitespace(str.charAt(i)) == false)) { return false; } } return true; }) .isPresent()时，会得到一堆文件名。在select physical_name from sys.database_files之后，BACKUP DATABASE的语法不是文件名，而是数据库名。

您的文件名包含路径，这会导致总路径太长而无法将其解释为数据库名称。如果路径较长，则会出现错误，即找不到具有该名称的数据库。这会更直接地告诉你你做错了什么。

您应该已经从连接字符串中获取了数据库名称。

The identifier that starts with … is too long. Maximum length is 128

1 个答案: