DATA RETRIEVING SYSTEM

PURPOSE:To retrieve required data by the small number of retrievals by converging keys to be set up next out of keys relating to a key set up by a user and providing only the key concerned out of the converged keys. CONSTITUTION:When a user sets up a retrieval condition and the setting is completed, 'RETRIEVAL' 31f is selected in a menu by using a mouse 33 to request retrieval. The retrieval is executed by the following three processes in accordance with the number of data to be retrieved. When there is no data coincident with a retrieving condition, the set key is changed, a changed candidate key for retrieval is inferred and a guide is displayed. In addition, the key causing the absence of the data coincident with the retrieving condition is decided. When there are too much data coincident with the retrieving condition, keys are added, the succeeding set candidate key for reretrieval is inferred and a guide is displayed. When the number of data coincident with the retrieving condition is in a proper range for inspecting the detailed contents of individual data, the retrieved data are displayed on a summary image display area 61.