MrC-temp
Note: The Regex() page is now at its permanent home: MC expression language page
Note: The File Properties page is now at its permanent home: File Properties (tags) page
This is MrC's working space for work-in-progress Wiki pages.
[ in progress, search and smartlist rules ]
Searching
Before getting too detailed, it is essential to have a basic understanding of how a query works in Media Center. Being at its core a database, the Media Center library maintains information (or properties) for each file (e.g. audio tracks, image files, video files, etc.) that has been imported.
Conceptually, when performing a query, Media Center tests a search phrase against each file in the library. If the search phrase evaluates to true for the file, the file is included in the final file list; otherwise, it is not.
A search phrase may be one or more search terms. Each search term, in order, is tested against every file in the current file list. The basic idea is that of filtering. From the list of all imported files, a initial search term reduces the list, and additional search terms further narrows the results to produce a final list of matching files.
Queries can generally test any file properties, or even test the results from an evaluated expression. So long as the query produces a true value (a value of 1), the file will be included.
Queries are used or input in numerous places throughout Media Center - they are the heart of what drives file list production used to populate Views (panes and categories values, file lists) and Smartlists, or via Search to narrow the list of files presented in the current view. Queries can be entered in the Search bar using Text or Wizard mode, the Edit Smartlist dialog box, and in any Set rules for file display dialog available in view customization (Standard View, Theater View, Gizmo/WebGizmo, Media Network's DLNA server).
A simple query might test some value against the contents of a specific property, such as the name of an album, a date, or episode number. For example, the following search phrase:
- [Album]=Pina
queries all files asking if the Album property contains the exact sequence of (case-insensitive) letters pina. Files that match are included in the resulting list; non-matching files are excluded.
Compound queries may be constructed by adding additional search terms, thus testing additional properties. Multiple search terms are combined by an implicit and operator. So it follows that the search phrase:
- [Name]=Midnight [Artist]=Thelonious
queries all files whose Name contains Midnight and from those, queries the current list to test that the Artist property contains Thelonious.
Generally, any library field may be used in a query; see the Media Center File Properties document for a list of the standard properties, and see Options > Library & Folders > Manage Library Fields for the complete list, including custom user fields.
Keep in mind that the order of the files returned from a query is generally undefined or random. Sorting is done by the view, or specifically by other query constructs such as Modifiers.
The next few sections describe the available operators available to construct search queries from simple to complex. Following that will be a description of search query Modifiers.
Comparison Operators
The query language provides the standard comparison operators of equal-to, less-than, less-than/equal-to, greater-than and greater-than/equal-to. These allow defining a search term to compare a specified value against a given field (also called property).
For date fields, values may include units such as d, w, y, h, m and s to indicate day, week, month, year, hour, minute, and second respectively. Floating point values may be used (e.g. .5w for 1/2 week).
| Operator | Description |
|---|---|
| field=value | Equal to the specified value.
Example: Return all files whose Artist field contains smith anywhere. [Artist]=Smith |
| field=<value | Less than the specified value.
Example: Return all files imported within the last 1/2 day (12 hours): [Date Imported]=<.5d |
| field=<=value | Less than or equal to the specified value.
Example: Return all files that are rated less than or equal to 2: [Rating]=<=2 |
| field=>value | Greater than the specified value.
Example: Return all files that are rated greater than 3: [Rating]=>3 |
| field=>=value | Greater than or equal to the specified value.
Example: Return all files whose bitrate is greater than or equal to 256kbps: [Bitrate]=>=256 |
Take note that the = character always follows a field name in comparison operations. In the case of equal to, the equivalence operator is implicit. This can be best illustrated by comparing the following example comparisons operations on the [Date (year)] field:
- [Date (year)]=1980
- [Date (year)]=<1980
- [Date (year)]=<=1980
- [Date (year)]=>1980
- [Date (year)]=>=1980
Quoting and Anchoring
Certain characters are used by the Media Center query language (e.g. <space> as the separator for search terms). To use these characters, they need to be quoted. Additionally, by default, Media Center queries are free to search anywhere within a given property. The special constructs listed below provide a means to both quote and anchor search terms.
A pair of double quotes " " is used to include spaces or special characters in a search phrase. Replacing the opening quote with an opening bracket [ will anchor the search to the beginning. Likewise, the closing quote may be replaced with a closing bracket ] to anchor at the end. Replacing both quotes will fully anchor the search, requiring a full match from beginning to end.
| Quote/Anchor | Description |
|---|---|
| "phrase" | Double quotes are used to include spaces or special characters in the search phrase. The phrase will match anywhere within a string.
Example: Match something that contains the string Steve Miller: "Steve Miller" |
| [phrase" | Same as double quotes above, but forces the phrase to match only at the beginning of the string.
Example: Match something that starts with Stan, such as Stan Getz, Stand by Me, but not One Standard Night: [Stan" |
| "phrase] | Same as double quotes above, but forces the phrase to match only at the end of the string.
Example: Match something that ends with stand, such as I Will Stand, I Didn't Understand, but not The Standards: "stand] |
| [phrase] | Same as double quotes above, but forces the phrase to match both at the beginning and end of the string.
Example: Match exactly Bob Dylan and exclude Bob Dylan & the Band: [Bob Dylan] |
| ^word | Restricts matching to a full word. A word is broken by space, punctuation, etc.
Example: Match car as a full word, as in A Car for All, but not Barcarolle. ^car |
Grouping and Combining
Multiple search terms can be combined to form more complex queries. Queries are read and evaluated left to right.
| Grouping | Description |
|---|---|
| s1 and s2 | Narrows the results returned by requiring matches of both of the search terms s1 and s2.
Example: Return all files by artist Frank Sinatra and orchestra Tommy Dorsey: [Artist]="Frank Sinatra" and [Orchestra]="Tommy Dorsey" Since the and operation is implicit between search terms, is it not required. The following search phrase is equivalent to that shown in the example above: [Artist]="Frank Sinatra" [Orchestra]="Tommy Dorsey" |
| s1 or s2 | Expands the results returned by accepting matches of either (or both) of the search terms s1 or s2.
Example: Return all files named Spying Glass or named Angel: [Name]=[Spying Glass] or [Name]=[Angel] |
| (s1 op s2) | Groups search terms to force precedence when using multiple search terms with the and and the or operators.
Example: Return all files whose artist is exactly Bob Dylan and whose year is either 1966 or 2001: [Artist]=[Bob Dylan] ([Date (year)]=1966 or [Date (year)]=2001) Note the distinction of the example above with the following example: [Artist]=[Bob Dylan] [Date (year)]=1966 or [Date (year)]=2001 The first example uses grouping parenthesis to force the order of evaluation, and returns files from Bob Dylan as the artist, from the year 1966 or 2001. The second example, due to order of evaluation from left to right, returns files with Bob Dylan as the artist from the year 1966, and also returns all files with year 2001. |
| val1,val2 | Combines two or more values into a list, identical to the or operator. No spaces are allowed between the comma(s) and the values.
Example: Return all files whose artist is any of Queen, Heart, or the Grateful Dead: artist=[Queen],[Heart],"Grateful Dead" The search phrase in the example above is identical to the more cumbersome: ([Artist]=[Queen] or [Artist]=[Heart] or [Artist]="Grateful Dead") |
Negation
| Negation | Description |
|---|---|
| -field | Inverts the sense of the comparison, returning those files whose field does not match the specified value. Usage is limited to the equality and comparison operators.
Example: Return all files whose track number is not 1: -[Track #]=1 Example: Return all files whose track number is not greater than or equal to 3: -[Track #]=>=3 Note that this equivalent to the more direct search phrase: [Track #]=<3 Example: Return all files by artist Mark Isham, except those whose album names begin with after or quiz, or end with home, and exclude files from 1993: [Artist]="Mark Isham" -[Album]=[after",[quiz","home] -[Date (year)]=1993 |
Modifiers
Queries and results can be modified by using one or more of the following special modifiers. Some modifiers act globally on, or affect the context of, the query, while others operate on the results returned as the query is being processed from left-to-right.
Some complex queries with modifiers will require manual entry in the Search Rules Importer/Exporter dialog available via the Import/Export button. The Edit Search wizard forces modifiers to the end of the query, thus removing the left-to-right processing required for certain modifiers such as ~seq or ~sort. Hint: always copy your complex query before leaving the Importer/Exporter so that it can be pasted again after testing.
Some of the modifiers below can operate on one or more fields. These compound field lists are expressed as a list of comma-separated fields [field1],[field2],...,[fieldn].
Note: For single character modifiers (i.e. ~n, ~d, ~s and ~t), the = character between the modifier and the value is optional (e.g., ~n30 is equivalent to ~n=30).
| Modifier | Description |
|---|---|
| ~d=database | Selects (limits) the Media Center database used in the query (e.g. Main, CD, Bad, Removed, etc.). More than one database may be specified by combining selectors.
Example: Limit the query to the CD and Main databases: ~d=cm |
| ~dup=fields | Returns a list of only duplicate files, where duplicates are determined by comparing the combined values in the specified fields list. Duplicate detection is based on matching values in fields, not by examining file content.
Example: Return a list of duplicate files by using the [Name] and [Artist] fields as the duplicate detectors: ~dup=[Name],[Artist] |
| ~nodup=fields | Returns a list with duplicate files removed, where duplicates are determined by comparing the combined values in the specified fields list. Only one of any duplicate file is included in the list. Duplicate detection is based on matching values in fields, not by examining file content.
Example: Return a list of all files with duplicates removed, by using the [Genre] field as the duplicate detectors. The returned list include one random file from each genre. ~nodup=[Genre] |
| ~fill | Returns a list of files to fill the specified device to maximum capacity. This modifier limits the number of files returned based on the amount of empty space left on the default or specified device.
Examples: Fill the default or specified device to maximum capacity: ~fill ~fill=[D:\] |
| ~a | Expands the track list (if necessary) to include the remaining tracks from the album(s).
Example: Return all tracks containing the name Feliz Navidad, and expand that list to include the remaining tracks in the album(s). If the track is on three albums, then all tracks from all three albums are returned. [Name]="Feliz Navidad" ~a |
| ~limit f,n,fields
|
Limits the set of files to at most n files from each of at most f values from the combined fields. This is easier explained with a simple example. From there, the general concept should be clearer.
Example: Limit the returned files, first by selecting at most 10 unique artists, and from each of those artists, return at most 2 files:
First 10 distinct artists will be randomly selected from the list of all possible artists, and then 2 random files from each of those artists will be selected and returned. If the limit cannot be satisfied (because there are too few artists, or too few files-per-artist), the available artists or files will be returned. In other words, these values are upper limits. The value of -1 is used to select all values, and can be used for either f or n. Example: Return all files from the Rock genre, but limit those results, first by randomly selecting at most 5 unique album / year pairs, and selecting all files from each of those albums:
|
| ~n=num | Limits to a maximum of num files.
Example: Return at most 20 randomly selected tracks:
|
| ~mix=n,s | Creates a mix of n files, according to the rules set by one or more comma-separated mix specifiers s. The format of each search specifier s is:
and val is either a number (e.g. 15) or a percentage (e.g. 10%), and criteria is a standard search phrase. The overall mix syntax follows the form:
The values val1, val2, ... should be either all percentages or all numeric, and should sum to either 100% or to the maximum number of tracks, respectively. Otherwise, the resulting mix proportions are not clearly defined. Example: Selecting from all Rock tracks, return a 10-track mixture with a 60/40 percentage split between artists whose names contain Mark or Tom, respectively.
|
| ~s=num | Limits the number of files such that the cumulative size does not exceed num megabytes.
Example: Return a random set of files totaling a maximum of 650MB.
|
| ~sort=fields | Sorts the list of files by the specified list of fields.
Example: Sort the list of files first by date, and then by track number:
Two special sort terms can be used: Random is used to randomize the order of list of files, and [Sequence] can be used to sort by the sequence number previously set with the ~seq modifier. Example: Randomize (shuffle) the list of files:
|
| ~t=num | Limits the cumulative track time to not exceed the num minutes.
Example: Limit the set of files to a maximum of 60 minutes:
|
| ~%=num | Limits the set of files to a maximum of num percent of the total possible.
Example: Randomly select and return 50% of the files imported into Media Center within the last week: [Date Imported]=<1w ~%=50 |
| ~seq | Assigns a monotonically increasing sequence number to the current set of files. This modifier is useful in a more complex query to return the sort order set earlier.
Example: Select all tracks imported in the past 4 weeks, and sort them in descending order by date imported, assign a sequence number to be used later, limit the number of tracks to two per album, and sort based on the sequence number assigned earlier: [Date Imported]=<4w ~sort=[Date Imported]-d ~seq ~limit=-1,2,[Album] ~sort=[Sequence] |
Search, Search Wizard and More
The query language has grown over time, and there are several ways to express an identical query. Where Search tries to do what you mean (by searching most fields automatically and presenting a list of possible matches from which to choose), the translation into the Search Wizard often requires a more specific or precise query. Also note that the Search Wizard tends to restructure queries, preferring the less ambiguous, but more pedantic form. This can result in some queries not translating accurately from Search into Search Wizard. For example, the loosely written three-term search query using the or operator
- [Artist]=[Queen] or [Artist]=[Heart] or [Artist]="Grateful Dead"
will be incorrectly translated by Search Wizard into a three-term and operation
- [Artist]=[Queen] [Artist]=[Heart] [Artist]="Grateful Dead"
instead of the correctly grouped search phrase
- ([Artist]=[Queen] or [Artist]=[Heart] or [Artist]="Grateful Dead")
Media Center file properties support search keywords, often abbreviations or alternate forms of the property name. These keywords can be used to specify searching a given field. For example, the [Date (year)] field can be specified either by using its full field name [Date (year)] or by using the year= search keyword. As mentioned above, when pushing a query from Search into the Search Wizard, search keywords are translated into the field's full name form. This can be seen by entering a search keyword into Search, and then entering Search Wizard and using the Import/Export button to examine the full query.
XXXX example: [Rating]=4 ([Genre]=[Rock" or [Date (year)]=1970-1980) is much different from r=4,5 genre=rock or year=1970-1980.
XXXX RANGE OPERATOR bugs?
XXXX FAILS: [lastplayed]=10-30
[last played]: h, d, w, y work, s, m fails; fractions are not working correctly (.6h-1h)
[Date Imported]=2d-3d
FAILS XXXX lastplayed=<60 XXXX [Last Played]=2-20 XXXX Note: The length field is calculated in seconds. The lastplayed field is calculated in minutes: <20 means smaller than, or within the last 20 minutes, whereas >20 means greater than, thus before the last 20 minutes. Using 10-30 means between 10 and 30 minutes.
Examples
Here are few examples of the kinds of rules you can create. The rules can be copy/pasted into the Search box, and you can use the Search Wizard for more assistance in developing search rules. Note: some of the examples show variations of the same rule, illustrating the use of full field names or their (keyword) abbreviations.
Greatest Hits: Return all files from album names containing Greatest Hits.
- [album]="Greatest Hits"
- al="Greatest Hits"
Date Imported: Return all files imported into Media Center in the past 7 days.
- [Date Imported]=<=7d
- dateimported=<=7d
Duration and Last Played: Return all tracks that are greater than 5 minutes (300 seconds) in duration (aka length) that have played in the last 60 minutes, and sort the results by track length.
- [Duration]=>300 [Last Played]=<60m ~sort=[Duration]
- length=>300 lastplayed=<60m ~sort=length
File Type and Artist: Return all mp3 files by artists whose names begin with Joe.
- [File Type]=mp3 [Artist]=[Joe"
Genres: Return all files that are in either the genre Opera or Classical.
- [Genre]=[Opera] or [Genre]=[Classical]
- g=[Opera] or g=[Classical]
Genre, Number of Plays, Excluding Artists, Shuffle: Return all files from genres beginning with Rock, where the number of plays is less than 5, and the Artist is neither Sting nor Beatles, and shuffle the results.
- [Genre]=[Rock" [Number Plays]=<5 -[Artist]=Sting,Beatles ~sort=Random
Playlist, Last Played, Limit Tracks: Return 10 random files from the "Top 40 1983" playlist which were not played in the last 5 days.
- [Playlist]="Top 40 1983" [Last Played]=>5d ~n=10
sort, rating, limit time
- ~sort=Random [Rating]=>=3 ~t=60
- Result: Find 60 minutes worth of files rated 3 or higher and sort them randomly.
mix
- g=rock ~mix=100,50%,{[Rating]=>3},25%,{[Rating]=1,2},25%,{[Rating]=[]}
- Result: play 100 rock tracks, 50% of which are rated 4 and 5, 25% of which are rated 1 and 2 and 25% unrated.
- ~mix=50,50%,{[Genre]=[Country Rock]},50%,{[Genre]=[Alternative Rock]}
- Result: play 50 tracks, ½ of which are Country Rock, and ½ of which are Alternative Rock.
limit
- [genre]=[rock] ~limit=7,-1,[album]
- Result: play only 7 rock albums.
- Explanation: for all rock, find only 7 albums, and play all (-1) tracks from that album.
- The syntax for use with ~limit is:
- ~limit=LIMIT_TOTAL_KEYS,LIMIT_PER_KEY,KEY_FIELDS
- This means: take a key field (e.g., album), limit the total of that field (7 albums, or –1 for unlimited), and of that total, limit again per field (2 tracks per album, or –1 for unlimited).
- ~limit=-1,1,[Artist] ~limit=-1,2,[Decade]
- Result: plays 10 tracks, 2 from each of the decades (a custom field) and the same artist appears only once.
- Explanation: The first limit: find unlimited artists (-1), and play only one track per artist (1). The second part means: find all decades (-1) and limit to 2 tracks per decade (2).
- [genre]=[rock] ~limit=7,2,[album]
- Result: From the rock genre, find 7 albums, and play only 2 tracks per album.
- Explanation: for all rock, limit the total albums to 7, and limit those 7 albums to 2 tracks each.
random year smartlist, 1930-1962
[Media Type]=[Audio] [Date (year)]=1930-1963 ~limit=1,-1,[Year] ~sort=Random