| 摘要 |
PROBLEM TO BE SOLVED: To reduce the preservation memory capacity and to quickly restore data by giving coordinates to individual items of data in a table form and preserving change values, the version number, and related data correspondingly to coordinates at the time of correction and restoring the change value of each coordinate only once retroactively from a designated version number at the time of restoration and eliminating preservation of duplicate data and restoration of duplicate values. SOLUTION: At the time of first input or correction of data where coordinates are given to individual items in a table form, a data preservation means 2 preserves first inputted values or changed values, the version number, and related data correspondingly to first inputted or corrected coordinates. A data restoration means 3 successively traces back preserved data from the designated version number or the latest version number to restore data in the same coordinates only once and perfroms this operation for all coordinates. |
