| 摘要 |
Systems and methods are provided that programmatically provide a user interface for forming a query, comprising. A query builder displays a first row of query criteria, a second row of query criteria, the second row being logically connected to the first row by a first Boolean connector, and a third row of query criteria, the third row being logically connected to the second row by a second Boolean connector. In response to a user drag-and-drop operation, the query builder nests the third row of query criteria in the second row of query criteria. Thus, a drag-and-drop operation obviates the need for cumbersome groups of parentheses when defining the order of operation of the query. |
