SQLite conditional Query

[Iczer]

maybe someone can look into this query (basically its folder-synchronising task) - it should select file (FilePathRelative) from rootFolder_2 if it not exist in or have older modification date, than same file in rootFolder_1

$s_query_string = "SELECT FilePathRelative, Time_Modified FROM SynchroDB WHERE rootFolder LIKE '"&$rootFolder_2&"' " & _
        "AND ((FilePathRelative Not IN (SELECT FilePathRelative FROM SynchroDB WHERE rootFolder LIKE '"&$rootFolder_1&"')) " & _
        "OR (FilePathRelative IN (SELECT FilePathRelative FROM SynchroDB GROUP BY FilePathRelative HAVING MAX(distinct Time_Modified)))) ORDER BY FilePathRelative;"

but it do not want to do it fo some reason

[jchd]

Is that what you need?

$s_query_string = _
"SELECT FilePathRelative, Time_Modified "& _
"FROM SynchroDB s" & _
"WHERE rootFolder LIKE '"&$rootFolder_2&"' " & _
    "AND Not exists (SELECT 1 FROM SynchroDB WHERE FilePathRelative = s.FilePathRelative and rootFolder LIKE '"&$rootFolder_1&"') " & _
    "OR Time_Modified < (SELECT Time_Modified FROM SynchroDB  WHERE FilePathRelative = s.FilePathRelative and rootFolder LIKE '"&$rootFolder_1&"') " & _
"ORDER BY FilePathRelative;"

[Iczer]

it seems pretty match like so...

didn't know about possibility of "select ... from db S where ..." construction... Maybe you can recommend me some kind of online collection/guide to sqlite queries it would be great help...

[jchd]

You can use the official website documentation http://www.sqlite.org/ and once there more precisely the SQL as Understood by SQLite pages which uses railroad diagrams to make most (but not all) syntax detail explicit.

Edited July 1, 2014 by jchd