Midas uses a Lucene engine to index item metadata. You may enter queries conforming to Lucene search syntax into the text area, and click "Search" to fetch results.

All item documents automatically contain the following fields:

• name - The name of the item
• description - The item description
• md5 - A list of all the MD5 checksums of the bitstreams in the item

Searches are case insensitive. If you wanted to search for an item whose name contained the token "turtle", you would type:

name: turtle

Which would return items such as TurtlePicture.jpg, MY_TURTLE, etc.

If you wanted to search for an item whose description contains any word starting with "foo", you can use the wildcard character *, as in the example below:

description: foo*

This would return items that had descriptions containing "foo", "fool", "football", etc.

You can also use boolean operators AND and OR in these queries, such as:

name: turtle AND description: foo*

In addition to these default fields, you may also search on a custom metadata field set on the item. These fields have user-defined types; each custom metadata field is prefixed with its type name. The list of type names is as follows:

• text - Tokenized text (the default)
• int - Integers
• long - Long Integers
• float - Floating Point numbers
• double - Double precision floating point numbers
• string - Non-tokenized string literals
• boolean - Boolean values

When searching, the type prefix must match the type that the field was declared as when it was added to the item. The format for searching by a custom metadata field is <type>-<element>.<qualifier>. For instance, if a user had set a custom metadata field on an item with the type "Integer", the element "DICOM", the qualifier "NumSlices", and the value "400", you could search for it using the metadata field as follows:

int-DICOM.NumSlices: 400

If the qualifier part was left empty, leave off the .qualifier portion of the field.