Disclosed herein is a
user interface and methods for building a formulated query to search a
database of structural data which is organized by classes, attributes of classes, literals of attributes, and structural relations between classes. The
user interface can display results of the formulated query and includes a structural query section to define constraints for the formulated query. The structural query section includes one or more query elements to be populated and a means for adding one or more additional query elements, wherein each query element can have a class portion which is populated by designating one of a
special class identifier and a concrete class identifier, and can have one or more attribute and literal portions. The class portion can be populated by designating the class identifier from an offered
list, and the
user interface can further include an offer section which displays the offered
list. The offered class identifiers, relation identifiers, attribute identifiers and literal values can come from the particular searched structural data. The offered class identifiers, relation identifiers and attribute identifiers can come from the definition of the structural content of the searched data. A relationship between query elements is expressible using a defined
structural relation, such as a “contains” relation. Relationships between two or more query elements or two or more query element attribute-literal pair portions are also expressible using
logical relations, such as a logical “AND” relation, a logical “OR” relation, and a logical “XOR” relation. A query results section displays results of the formulated query after the formulated query is executed.