Patent ID: 8386452

Claim:
A data join system for joining join source data including an identification item and a key item with selected join target data which is one of join target data selected from a join target data group having a plurality of join target data including an identification item and a key item, the data join system comprising: a join source data storage section configured to store the join source data; a join target data storage section configured to store the join target data group; a data determination section configured to select join target data as the selected join target data if a value of the identification item included in one of join source data stored in the join source data storage section agrees with a value of the identification item included in the join target data stored in the join target data storage section or falls within a predetermined identification range set based on the value of the identification item included in the join target data, and if a value of the key item included in the join source data falls within a first predetermined range set based on a value of the key item included in the join target data; a data join section configured to join the selected join target data selected by the data determination section with the join source data to generate composite data; a composite data storage section configured to store the composite data; and a data write section configured to store the composite data generated by the data join section into the composite data storage section, wherein the predetermined identification range is a finite range including a value of the identification item included in the join target data, the first predetermined range is a finite range including a value of the key item included in the join target data, and when the selected join target data cannot be selected based on the first predetermined range, the data determination section selects join target data as the selected join target data if a value of the identification item included in the one of join source data agrees with a value of the identification item included in the join target data stored in the join target data storage section or falls within a predetermined range set based on the value of the identification item included in the join target data, and if a value of the key item included in the join source data falls within a second predetermined range set adjacent to the first predetermined range.