C#对现有sqlite数据库中、特定表中是否存在某列、

 1 System.Data.SQLite.SQLiteConnection conne = new System.Data.SQLite.SQLiteConnection();
 2 System.Data.SQLite.SQLiteConnectionStringBuilder connstr = new System.Data.SQLite.SQLiteConnectionStringBuilder();
 3 connstr.DataSource = System.AppDomain.CurrentDomain.BaseDirectory + "//DB//Course.db";
 4 conne.ConnectionString = connstr.ToString();
 5 conne.Open();
 6 
 7 System.Data.SQLite.SQLiteCommand cmd = new System.Data.SQLite.SQLiteCommand();
 8 
 9 string sql = "Select * From UserLoginInfo WHERE UserAccount =‘-------‘";
10 cmd.CommandText = sql;
11 cmd.Connection = conne;
12 
13 System.Data.SQLite.SQLiteDataAdapter adapter = new System.Data.SQLite.SQLiteDataAdapter(cmd);
14 DataSet data = new DataSet();
15 adapter.Fill(data);
16 DataTable table = data.Tables[0];
17 
18 bool HasShowAccount = false;
19 for (int i = 0; i < table.Columns.Count; i++)
20 {
21     if (table.Columns[i].ColumnName.Equals("ShowAccount"))
22     {
23         HasShowAccount = true;
24     }
25 }
26 
27 if (!HasShowAccount)
28 {
29     sql = "alter table UserLoginInfo add column ShowAccount CHAR(50)";
30     cmd.CommandText = sql;
31     cmd.ExecuteNonQuery();
32 }
33 conne.Close();