Data acquisition device, data acquisition method and computer readable medium
The present invention is provided with a command acceptance unit ( 110 ) to accept a query command ( 201 ) to acquire data from a database, the query command including a value designation range to designate a range of a definition value corresponding to the data to be acquired, an acquisition definition storage unit ( 160 ) to store acquisition definition information ( 161 ) wherein a value definition range is associated with an acquisition method to acquire data from the database, and a command generation unit ( 120 ) to judge whether a range that overlaps with the value definition range exists in the value designation range, and when it is judged that the overlapping range exists, to generate a data acquisition command ( 202 ) to acquire data corresponding to a definition value included in the overlapping range in an acquisition method corresponding to the value definition range.
1. A data acquisition device comprising:
a memory having stored therein acquisition definition information, wherein a value definition range that defines a range of a definition value is associated with an acquisition method to acquire data from a database and the acquisition method for at least one respective definition value varies according to the defined range; and
processing circuitry configured to:
accept, from an application execution device, a query command to acquire data from the database that stores data which is associated with a definition value, the query command including a value designation range that designates a range of a definition value corresponding to the data to be acquired;
judge, by using the query command and the acquisition definition information, whether an overlapping range that overlaps with the value definition range exists in the value designation range,
when the overlapping range is judged to exist, analyze the query command to determine whether there are any candidate parts which need to be rewritten based on the stored acquisition definition information;
rewrite, when there is candidate part which needs to be rewritten, the query command based on the acquisition definition information,
generate, when the query command has been rewritten, based on the rewritten query command and the acquisition definition information, a data acquisition command to acquire data corresponding to a definition value which is included in the overlapping range, in an acquisition method corresponding to the value definition range;
output, when there is no candidate part which needs to be rewritten, the query command as the data acquisition command;
acquire data from the database by using the data acquisition command; and
provide the acquired data to the application execution device in response to the accepted query.
2. The data acquisition device as defined in claim 1 , wherein
the processing circuitry stores the acquisition definition information including a plurality of value definition ranges as the value definition range, wherein each value definition range of the plurality of value definition ranges is associated with the acquisition method, and
judges whether an overlapping range that overlaps with each value definition range of the plurality of value definition ranges exists in the value designation range, and when the overlapping range is judged to exist, generates the data acquisition command to acquire data corresponding to a definition value included in the overlapping range in an acquisition method corresponding to each value definition range of the plurality of value definition ranges.
3. The data acquisition device as defined in claim 2 , wherein when it is judged that a range that does not overlap with any value definition range of the plurality of value definition ranges exists in the value designation range, the processing circuitry makes a command to acquire a default value as data corresponding to a definition value included in the range that does not overlap be included in the data acquisition command.
4. The data acquisition device as defined in claim 3 , wherein the memory stores undefined information including the default value acquired as the data corresponding to the definition value included in the range that does not overlap.
5. The data acquisition device as defined in claim 2 , wherein the processing circuitry registers in the acquisition definition information each value definition range of the plurality of value definition ranges and the acquisition method corresponding to each value definition range of the plurality of value definition ranges.
6. The data acquisition device as defined in claim 5 , wherein the processing circuitry registers each value definition range of the plurality of value definition ranges so that each value definition range of the plurality of value definition ranges does not overlap with other value definition ranges.
7. The data acquisition device as defined in claim 6 , wherein when each value definition range of the plurality of value definition ranges overlaps with other value definition ranges, the processing circuitry reduces each value definition range of the plurality of value definition ranges or the other value definition ranges so that each value definition range of the plurality of value definition ranges does not overlap with the other value definition ranges.
8. The data acquisition device as defined in claim 1 , wherein the definition value is a date and time.
9. The data acquisition device as defined in claim 1 , wherein the definition value is determined from a plurality of conditions.
10. A data acquisition method comprising:
storing acquisition definition information, where a value definition range that defines a range of a definition value is associated with an acquisition method to acquire data from a database, wherein the acquisition method for at least one respective definition value varies according to the defined range; and
accepting, from an application execution device, a query command to acquire data from the database that stores data which is associated with a definition value, the query command including a value designation range that designates a range of a definition value corresponding to the data to be acquired,
judging, using the acquisition definition information and the query command, whether an overlapping range that overlaps with the value definition range exists in the value designation range,
when the overlapping range is judged to exist, analyzing the query command to determine whether there are any candidate parts which need to be rewritten based on the stored acquisition definition information,
rewriting when there is a candidate part which needs to be rewritten, the query command based on the acquisition definition information,
generating, when the query command has been rewritten, based on the rewritten query command and the acquisition definition information, a data acquisition command to acquire data corresponding to a definition value which is included in the overlapping range, in an acquisition method corresponding to the value definition range,
outputting, when there is no candidate part which needs to be rewritten, the query command as the data acquisition command;
acquiring data from the database by using the data acquisition command; and
providing the acquired data to the application execution device in response to the accepted query.
11. A non-transitory computer readable medium storing a data acquisition program to make a computer execute:
storing acquisition definition information, where a value definition range that defines a range of a definition value is associated with an acquisition method to acquire data from a database, wherein the acquisition method for at least one respective definition value varies according to the defined range; and
accepting, from an application execution device, a query command to acquire data from the database that stores data which is associated with a definition value, the query command including a value designation range that designates a range of a definition value corresponding to the data to be acquired,
judging, by using the acquisition definition information and the query command, whether an overlapping range that overlaps with the value definition range exists in the value designation range,
when the overlapping range is judged to exist, analyzing the query command to determine whether there are any candidate parts which need to be rewritten based on the stored acquisition definition information,
rewriting, when there is a candidate part which needs to be rewritten, the query command based on the acquisition definition information,
generating, when the query command has been rewritten, based on the rewritten query command and the acquisition definition information, a data acquisition command to acquire data corresponding to a definition value which is included in the overlapping range, in an acquisition method corresponding to the value definition range,
outputting when there is no candidate part which needs to be rewritten, the query command as the data acquisition command;
acquiring data from the database by using the data acquisition command; and
providing the acquired data to the application execution device in response to the accepted query.