Filter operators
About Filter Operators
Filter operators work as part of refining your search. After you click on the filter icon a number of different operators are available in the filter windows depending on the type of data you want to filter on. For example if you want to filter on User Locations there is a choice of operator - 'Is One Of' or 'Is Not One Of'. This is a list filter and you can use 'Is One Of' with a value from the list of values displayed. Other filters allow you to filter on a value that you enter e.g. a Borrower (user) name, and there are value operators that are used with this such as 'Equals', 'Similar To'. Date filters also use specific operators e.g. Date Last Changed allows you to enter a date together with a choice of date operators - 'Between', 'After', 'Before' etc.. All the filter options are automatically combined with your search criteria using the Boolean operator AND.
Note: all filter values are case sensitive.
Boolean Operators
When you select the filter option to use, e.g. Date Entered the AND Boolean operator is set by default. This means your search criteria in the search entry box is 'AND-ED' with the filter criteria.
The Boolean operators are also used when you enter more than one filter for the search e.g. Date Entered AND Entered By. Where more than one filter is present the Boolean operators AND OR are used to combine the filters together (AND is the default). This has the following effect in this example of a configured search:
| Search criteria | The search will combine these as follows |
|---|---|
|
AND filter1 OR filter2 |
search criteria AND (filter OR filter2) |
In practice, most filters are 'AND-ED' together and the overall effect of this is to reduce the number of hits retrieved.
Filter on List
This type of filter allows you to choose from a list of given items, e.g. a list of Media Types:
| Filter | Behaviour |
|---|---|
| Is One Of | Find matches where one of the following items applies. |
| Is Not One of | Find matches where one of the following items does not apply. If any null values exist these will not be matched. |
- Search for the items and click Refine Search as above.
- In the Refine Search dialog, select the field you want to filter on, e.g. Media Type.
- Click the Filter on List icon
In the Select List Refinements box, all refinements are shown, e.g. all the OLIB Media Types.
- A Search List box is also available to search long lists. Enter a few letters / word to obtain a sub-set:
- Optionally you can also use Select/Deselect All buttons.
The Select All and Deselect All buttons act only on the items that are visible. Selections are preserved even if the item is not visible. The user can therefore search for e.g. John, click Select All, search again for Smith and click Deselect All. This will result in a list of values containing John, but not Smith.
Filter on Value (text refinements)
This type of filter works with alphanumeric data that you must type in, e.g. Borrower. The options include:
| Filter | Behaviour |
|---|---|
| Similar to |
This option has been amended to be not case sensitive. This was always the situation for fields that are normalised, but it has been extended to all fields. This change may have a noticeable performance impact. Contact OCLC Support if there is a requirement for a refinement on a particular field that is causing a problem. |
| Equals | Find an exact match with the value; does not match with null values; a case sensitive match on the entire value. |
| Begins with |
This option provides the same functionality as given by "Similar to" prior to Service Pack 11 - a case sensitive match on the start of the text. In many cases this option will perform significantly better than "Similar to". It is therefore highly recommended that this option be chosen for Saved Searches. |
| Not equals | Find a match that should not equal (exactly), the value entered; a case sensitive match on the entire value to exclude results. |
| Coalesced |
This is intended to facilitate refinements for fields that contain data such as telephone numbers, postcodes or other code values. It will carry out a case insensitive match on only the letters and numbers entered. For example, "01142677502" will match "(0114) 267-7502", and "s14lw" will match "S1 4LW". |
| Between |
This is a new option - a case sensitive match to facilitate a range search. This option can be useful, for example, to limit a title search to titles that have a copy record with a shelfmark between the two values entered. The match is inclusive at both ends of the range. For example, specifying between "123" and "456" will include both "123" and "456". However, it will not include"456.7" |
| Before | Find a match that is immediately preceding the value entered (using alphanumeric comparison); a case sensitive match to facilitate an open-ended range search. |
| After | Find a match that is immediately following the value entered (using alphanumeric comparison); a case sensitive match to facilitate an open-ended range search. |
Filter on Date
This type of filter works on date fields only, e.g. Join Date (Users), Date Catalogued (Titles).
| Filter | Behaviour |
|---|---|
| Between | Find a match that is between date1 and date2 inclusive. |
| After | Find a match that is after and not on the date value entered. |
| Before | Find a match that is before and not on the date value entered. |
| Equals | Finds a match with the date value you enter regardless of the time component. |
| Not Equals |
Find matches that do not match the date value ( regardless of time component, does not match with null values). The time component is noted if Use Time Format box is checked; null values will be matched if Accept Null Date is checked. |
| Accept Null Date | If this is checked then the search should include matches where no date is present. |
| Use Time Format | If this is checked then the time component should be included in the search. |
When you choose a Date filter, the date or days entry fields appear, depending on your chosen operator, such as "After".
E.g. Date Last Modified - After
You can enter the exact date using the calendar picker, or you can enter the number of days in the days ago box.
days ago
Use this in conjunction with a suitable operator.
For example:
"Equals 90 days ago" will list everything that was changed 90 days ago
"After 90 days ago" will list everything that has been changed since 90 days ago
When you choose the Between operator, OLIB displays 2 sets of fields:
[enter date] or [nn] days ago
and
[enter date] or [nn] days ago
If you are entering a "between x and y days ago", the larger number must be on the left (listed first).
For example:
"between 21 and 7 days ago"
not
"between 7 and 21 days ago"
If you put a value in days ago it will be used instead of any value in the associated date field.
You can remove all filter operations by clicking 