public static DataTable GetLectuer(MyMySql sql)
{
string sqlstr = $@"
SELECT * FROM lecture";
return(sql.executeQuery(sqlstr));
}
public static DataTable GetBooks(MyMySql sql)
{
string SQLstr = $@"
SELECT * FROM books;";
return(sql.executeQuery(SQLstr));
}
public static DataTable getUnAviliableSeats(MyMySql sql, string roomid)
{
string sqlstr = $@"
SELECT
deskid, seatid
FROM
seats
WHERE
roomid = {roomid}
AND backdatetime IS NULL";
return(sql.executeQuery(sqlstr));
}
public static string[] getBooksByTag(MyMySql sql, string tagid)
{
string sqlstr = $@"
SELECT bookid
FROM book_tag
WHERE tagid = {tagid}
GROUP BY bookid";
DataTable table = null;
if ((table = sql.executeQuery(sqlstr)) != null)
{
string[] result = table.AsEnumerable().Select(d => d.Field <string>("bookid")).ToArray <string>();
return(result);
}
return(null);
}
public static DataTable GetAllUsers(MyMySql sql_users)
{
return(sql_users.executeQuery(@"SELECT * FROM users"));
}