/// <summary>
/// 删除字段
/// </summary>
/// <param name="connName">连接名</param>
/// <param name="tableName">表名</param>
/// <param name="fieldName">字段名</param>
public static void deleteField(string connName, string tableName, string fieldName)
{
DatabaseAdmin da = DatabaseAdmin.getInstance(connName);
da.deleteField(tableName, fieldName);
}