JP4675748B2 - XML data conversion device and XML data restoration device - Google Patents

Description

  The present invention relates to an XML document database having a tree structure described in XML (Extensible Markup Language), and more particularly to an XML data conversion device for converting an XML document into tabular table data, and The present invention relates to an XML data restoration apparatus for restoring an XML document from such table data.

  Conventionally, various methods have been adopted for converting an XML document into a table format and storing it in a database, and retrieving the stored data at high speed.

  A typical method is to create a rule for converting a schema from a schema defining the structure of an XML document, such as DTD (Document Type Definition), XML Schema, RELAX NG, etc. There is a method of converting into a plurality of tables for each type or for each node name. For example, in Patent Document 1, a table is created for each element having the same name based on the schema, and the contents of each element and attribute value items and the link relationship between the tables are stored in the table.

JP 2004-178084 A

As a problem of the conventional method, the first problem is that a schema is essential for conversion. Therefore, there is a problem that a valid XML document having a schema can be converted, but a verified XML document that does not require a schema cannot be converted.
The second problem is that a plurality of tables are required. As the number of tables increases, there is a problem that storage and retrieval processing becomes complicated.

  The present invention has been made to solve the above problems, and XML data that can convert a verified XML document that does not require a schema into a single table that can be restored to the original XML document. An object is to obtain a conversion device and an XML data restoration device.

The XML data conversion apparatus according to the present invention includes a node name extraction unit that extracts identification information of each node from the XML data, and a bit only for a predetermined type of node according to the type of each node of the XML data. A bit grant unit that does not give bits to other types of nodes, a node depth measurement unit that measures the node depth when each node is represented by a tree structure, and a bit grant unit Based on the presence / absence of a given bit and the node depth measured by the node depth measurement unit, the measured value of the node depth is multiplied by n (n is an arbitrary natural number of 2 or more), and the bit is If it is given, it is provided with a bit / depth combination part that generates a numerical value to which 1 is added and outputs the numerical value as a numerical value corresponding to the identification information of each node.

The XML data conversion apparatus according to the present invention generates a numerical value indicating the type of each node and the node depth based on the presence / absence of bit assignment according to the type of each node of the XML data and the node depth. Since it is output as a numerical value corresponding to the identification information, the XML structure can be expressed with a small numerical value without requiring a schema to generate table data, and can be restored to the original XML data. Can be converted into table data.

Embodiment 1 FIG.
In the present invention, the nodes of the XML document include “non-empty element” which is the most basic information unit in the XML document, “empty element” which is an empty element having no content, and elements in the XML document. It is assumed that there are five types of “attribute” to which additional information is added, “element text” that is an element value, and “attribute text” that is an attribute value.

  On the other hand, as an XML document node, an “XML declaration” that declares that the document is an XML document, a “processing instruction” that describes a processing instruction to the application, and a statement that ignores logic or semantic structure as an XML document element “CDATA section” to describe, “comment” to describe a sentence that is not interpreted as an XML document element, “character reference” to describe a character reference by character code, and “entity reference” to describe an entity representing a character string or a file It shall not be included. Here, since “XML declaration”, “processing instruction”, “CDATA section”, “comment”, “character reference”, and “entity reference” are not main nodes in the XML document, they are considered in the database of the XML document. There is no big problem even if not.

  Further, ignorable line breaks and spaces (so-called “ignorable white space”) between nodes are not treated as nodes and are ignored. For example, in the XML document of FIG. 2 described later, line breaks are made from <aaa> to <bbb />, from <bbb /> to <ccc ddd = "eee">, and from </ ccc> to </ aaa>. There are spaces and spaces, but they are not treated as nodes and ignored.

  Also, in DOM (Document Object Model) which is a typical API (Application Programming Interface) of an XML document, “attribute” is not handled as a child node of “element”. In the present invention, “attribute” is handled as a child node of “element”, but there is no particular problem.

FIG. 1 is a configuration diagram showing an XML data conversion device and an XML data restoration device according to Embodiment 1 of the present invention.
In the figure, the XML data conversion device and the XML data restoration device are composed of an XML document storage unit 10, a table storage unit 20, a conversion unit 30, and a restoration unit 40, and the conversion unit 30 serves as the XML data conversion device. The restoration unit 40 corresponds to an XML data restoration device.

  The XML document storage unit 10 is original data that is converted into table format data by the conversion unit 30 and is a storage unit for storing the XML document restored by the restoration unit 40. The conversion unit 30 is a functional unit that converts an XML document stored in the XML document storage unit 10 into data in a table format and sends the data to the table storage unit 20, and includes a node name extraction unit 31, a bit addition unit 32, and a node A depth measurement unit 33 and a bit / depth combination unit 34 are provided.

  The node name extraction unit 31 is a functional unit that extracts a node name from the XML document extracted from the XML document storage unit 10 as node identification information. The bit assigning unit 32 is a bit indicating the type of “non-empty element”, “empty element”, “attribute”, “element text”, and “attribute text” that are information indicating the type of the node described above from the XML document. It is a functional part that gives That is, of “non-empty element”, “empty element”, “attribute”, “element text” and “attribute text”, the bit is turned on for “attribute” and “element text”, and the bit is set otherwise. off. The node depth measurement unit 33 is a functional unit that measures the depth when each node of the XML document is represented by a tree structure. The bit / depth combination unit 34 is a numerical value indicating the type of node and the node depth based on the bit provided by the bit providing unit 32 and the value indicating the depth measured by the node depth measurement unit 33. Is generated in correspondence with the node name extracted by the node name extraction unit 31, and is output as data in a table format.

  The restoration unit 40 is a functional unit that restores an XML document from data in a table format stored in the table storage unit 20, and includes a node name assignment unit 41, a node type restoration unit 42, a tree structure restoration unit 43, a bit / depth A thickness division unit 44 is provided. The node name assigning unit 41 to the bit / depth dividing unit 44 perform a restoring operation corresponding to the conversion operation in the node name extracting unit 31 to the bit / depth combining unit 34, respectively.

  The bit / depth division unit 44 is a functional unit that extracts the type of the node and the value indicating the depth of the node in the tree structure from the numerical values corresponding to each node in the table data. The tree structure restoration unit 43 is a functional unit that restores the tree structure of the XML document based on the value indicating the node depth extracted by the bit / depth division unit 44. Based on the value indicating the node type extracted by the bit / depth dividing unit 44, the node type restoration unit 42 converts each node indicated by the tree structure into “non-empty element” and “empty element” which are node types. It is a functional unit that restores as “attribute”, “element text”, and “attribute text”. The node name assigning unit 41 is a functional unit that assigns a node name that is node identification information to each node restored by the node type restoring unit 42 and outputs the node name as an XML document to the XML document storage unit 10.

Next, the operation of the first embodiment will be described.
First, a method for converting an XML document into table data will be described.

First, the conversion unit 30 takes out an XML document to be converted into a table from the XML document storage unit 10.
FIG. 2 is an explanatory diagram illustrating an example of an XML document.

  In the conversion unit 30, after extracting the XML document, the node name extraction unit 31, the bit assignment unit 32, and the node depth measurement unit 33 perform the following three operations on each node of the XML document.

(1) The node name extraction unit 31 acquires the name of the node.
(2) The bit assigning unit 32 assigns a bit “node type restoration bit” for enabling the XML document to be restored later from the table. Specifically, the bit assigning unit 32 assigns the node type restoration bit on when the node type is “attribute” or “element text”. When the node type is “non-empty element”, “empty element”, or “attribute text”, the node type restoration bit off is added.
(3) The node depth measuring unit 33 measures the depth of the node when the depth of the root node is 1. Therefore, the depth of the child node of the root node is 2, the depth of the child node is 3, and so on.

  Further, (4) the bit / depth combining unit 36 combines the node type restoration bit value (2) provided by the bit providing unit 32 and the depth (3) measured by the node depth measuring unit 33. Specifically, when the depth of (3) measured by the node depth measurement unit 33 is doubled and the node type restoration bit value of (2) provided by the bit addition unit 32 is on, further Add one.

  After the above operation, in the order in which the nodes appear, the conversion unit 30 extracts the name of the node of (1) extracted by the node name extraction unit 31 in the first column of the nth row of the table if it is the nth node, The values of (4) combined by the bit / depth combining unit 36 are stored in the second column of the nth row of the table. Therefore, an XML document with n nodes can be converted into a table with n rows and 2 columns.

Specific operations (1) to (4) will be described by taking the XML document shown in FIG. 2 as an example.
FIG. 3 is an explanatory diagram showing a tree structure of the XML document shown in FIG.
FIG. 4 is an explanatory diagram of a table obtained by converting the XML document shown in FIG.

  First, in the node aaa, the node name extraction unit 31 extracts the node name aaa. Since the node of aaa is “a non-empty element”, the bit assigning unit 32 assigns the node type restoration bit off. Since the node aaa is a root node and the depth of the root node is 1, the node depth measurement unit 33 obtains a depth of 1. The bit / depth combination 36 doubles the depth 1 to obtain 2. With the above operation, the conversion unit 30 stores aaa in the first column of the first row of the table and 2 in the second column of the first row.

  Next, in the node bbb, the node name extraction unit 31 extracts the node name bbb. Since the node of bbb is an “empty element”, the bit assigning unit 32 assigns the node type restoration bit off. Since the node depth of bbb is 2, the node depth measurement unit 33 obtains the depth 2. The bit / depth combination 36 doubles the depth 2 to obtain 4. With the above operation, the conversion unit 30 stores bbb in the first column of the second row of the table and 4 in the second column of the second row.

  In the ccc node, the node name extraction unit 31 extracts the node name ccc. Since the node of ccc is “a non-empty element”, the bit assigning unit 32 assigns the node type restoration bit off. Since the node depth of ccc is 2, the node depth measurement unit 33 obtains the depth 2. The bit / depth combination 36 doubles the depth 2 to obtain 4. With the above operation, the conversion unit 30 stores ccc in the first column of the third row and 4 in the second column of the third row.

  In the ddd node, the node name extraction unit 31 extracts the node name ddd. Since the node of ddd is “attribute”, the bit assigning unit 32 assigns the node type restoration bit on. Since the “attribute” is a child node of “element”, the depth of the node of ddd is 3, so the node depth measurement unit 33 obtains a depth of 3. The bit / depth coupling part 36 doubles the depth 3 and adds 1 to obtain 7. With the above operation, the conversion unit 30 stores ddd in the first column of the fourth row of the table and 7 in the second column of the fourth row.

  In the eee node, the node name extraction unit 31 extracts the node name eee. Since the node of eee is “attribute text”, the bit assigning unit 32 assigns the node type restoration bit off. Since the node depth of eee is 4, the node depth measurement unit 33 obtains the depth 4. The bit / depth combination 36 doubles the depth 4 to obtain 8. With the above operation, the conversion unit 30 stores eee in the first column of the fifth row of the table and 8 in the second column of the fifth row.

In the fff node, the node name extraction unit 31 extracts the node name fff. Since the node of fff is “element text”, the bit assigning unit 32 assigns the node type restoration bit on. Since the node depth of fff is 3, the node depth measurement unit 33 obtains a depth of 3. The bit / depth coupling part 36 doubles the depth 3 and adds 1 to obtain 7. With the above operation, the conversion unit 30 stores fff in the first column of the sixth row and 7 in the second column of the sixth row.
The table in which the XML document is converted by the operations (1) to (4) is finally as shown in FIG.

  After the values are stored in the table, the conversion unit 30 stores the table obtained by converting the XML document in the table storage unit 20.

  As a result of the above operation, any verified XML document including nodes of “non-empty element”, “empty element”, “attribute”, “element text”, and “attribute text” is converted into a single two-column table. be able to.

Next, a method for restoring the original XML document from the above-described two-column table will be described.
First, the restoration unit 40 extracts a table to be restored to an XML document from the table storage unit 20. After taking out the table to be restored, the bit / depth dividing unit 44 divides the values in the second column of the table into the node type restoration bit and the node depth. Specifically, the remainder obtained by dividing the value in the second column of the nth row of the table by 2 is the bit assigned to the nth, and the quotient is the depth of the nth node.

The operation of the bit / depth dividing unit 44 will be described with reference to the table of FIG.
When the value 2 in the second column of the first row is divided by 2, the remainder is 0 and the quotient is 1, so the node type restoration bit off is given to the first node, and the depth of the first node is 1. It is.
If the value 4 in the second column in the second row is divided by 2, the remainder is 0 and the quotient is 2, so the node type restoration bit off is given to the second node, and the depth of the second node is 2. It is.
When the value 4 in the second column of the third row is divided by 2, the remainder is 0 and the quotient is 2, so the node type restoration bit off is given to the third node, and the depth of the third node is 2. It is.
When the value 7 in the second column of the fourth row is divided by 2, the remainder is 1 and the quotient is 3, so the node type restoration bit on is assigned to the fourth node, and the depth of the fourth node is 3. It is.
When the value 8 in the second column of the fifth row is divided by 2, the remainder is 0 and the quotient is 4, so the node type restoration bit off is given to the fifth node, and the depth of the fifth node is 4. It is.
When the value 7 in the second column of the sixth row is divided by 2, the remainder is 1 and the quotient is 3, so the node type restoration bit on is assigned to the sixth node, and the depth of the sixth node is 3 It is.

  After the bit / depth division, the tree structure restoration unit 43 restores the tree structure of the XML document from the depth information obtained by the bit / depth division unit 44. Here, if the parent node of its own node is known, the tree structure can be restored in order. The rule for searching for the parent node of his node is as follows: “A parent node of a node is one shallower than that node and is the closest node that appears before his node.”

The operation of the tree structure restoration unit 43 will be described with reference to the table shown in FIG.
Since the first is the root node, there is no parent node.
The parent node of the second node is the first.
The parent node of the third node is the first.
The parent node of the fourth node is the third.
The parent node of the fifth node is the fourth.
The parent node of the sixth node is the third.
The tree structure of the XML document that can be restored from the two-column table by the above operation is as shown in FIG. Here, the numbers with circles correspond to the data in the first to sixth rows of the table of FIG. Further, the black circle numbers indicate that the node type restoration bit is on.

After the tree structure restoration, the node type restoration unit 42 restores the node type from the node type restoration bit on / off and the node tree structure information.
In the present invention, the node type can be restored by the following restrictions.
“Attribute” always has a child node, which is “attribute text”.
• “Element text” has no child nodes.
Due to the above limitations, (1) “attribute” and “element text” whose bit is on can be identified by whether or not they have child nodes. (2) The “element” and the “attribute text” whose bits are off can be identified by whether or not the parent node is an attribute. (3) Further, “non-empty element” and “empty element” can be identified by having a child node.

FIG. 6 is a flowchart showing the restoration process.
That is, when the bit is on (step ST61) and has a child node (step ST62), the node type restoration unit 42 has the node type “attribute”, the bit is on (step ST61), and has no child node. In the case of (step ST62), it is determined as “element text”. If the bit is off (step ST61), the parent node is not an attribute (step ST63), and has no child nodes (step ST64), it is “empty element”, the bit is off (step ST61), and the parent node is If it is not an attribute (step ST63) and has a child node (step ST64), "non-empty element", if the bit is off (step ST61) and the parent node is an attribute (step ST63), "attribute text" Is determined.

Hereinafter, the specific operation of the node type restoration unit 42 will be described with reference to FIGS.
The first node is No in the conditional branch in step ST61, No in the conditional branch in step ST63, and Yes in the conditional branch in step ST64, and the first node is an “non-empty element”.
In the second node, No in the conditional branch in step ST61, No in the conditional branch in step ST63, No in the conditional branch in step ST64, and the second node is an “empty element”.

The third node is No in the conditional branch in step ST61, No in the conditional branch in step ST63, and No in the conditional branch in step ST64, and the third node is a “non-empty element”.
The fourth node is Yes in the conditional branch in step ST61 and Yes in the conditional branch in step ST62, and the fourth node is an “attribute”.
The fifth node is No in the conditional branch in step ST61 and Yes in the conditional branch in step ST63, and the fifth node is “text of attribute”.
In the sixth node, Yes in the conditional branch in step ST61, No in the conditional branch in step ST62, and the sixth node is “element text”.

After restoring the node type, the node name assigning unit 41 assigns the name of the node stored in the first column of the nth row of the table to the nth node.
The operation of the node name assigning unit 41 will be described using the table in FIG. 4 as an example.
Since the value in the first column of the first row of the table is aaa, the name of the first node is aaa.
Hereinafter, the names of the nodes can be similarly obtained for the second to sixth lines.

With the information obtained by the operations of the node name assigning unit 41 to the bit / depth dividing unit 44 described above, the tree structure of the node, the type of each node, and the name of each node are complete, so that it can be restored as an XML document. it can.
Finally, the restoration unit 40 stores the restored XML document in the XML document storage unit 10.

  With the above operation, a verified XML document including nodes of “non-empty element”, “empty element”, “attribute”, “element text”, and “attribute text” can be restored from the two-column table.

  In the first embodiment, the bit / depth coupling unit 34 doubles the depth measurement value. However, the bit / depth coupling unit 34 is not limited to twice, and the multiple is an arbitrary natural number of 2 or more. If it is. However, by reducing the multiple, the numerical value in the second column is reduced, and the amount of information can be reduced.

As described above, according to the XML data conversion apparatus of the first embodiment, the XML data conversion apparatus converts XML data into table data composed of identification information of each node of XML data and numerical values corresponding thereto. A node name extraction unit that extracts identification information of each node from the XML data, and a bit is given only to a predetermined type of node according to the type of each node , and other types of nodes A bit granting unit that does not grant bits, a node depth measurement unit that measures the node depth when each node is represented by a tree structure, presence / absence of bit granting given by the bit granting unit, and a node based on the node depth measurement by the depth measuring unit, the node n a measurement of the depth (n is an arbitrary natural number of 2 or more) multiplied and if the bit is imparted added 1 Generating a number, since a bit depth coupling unit for outputting a value corresponding to the numerical identity of each node, small structures of XML without requiring schema to generate the table data It can be converted into single table data that can be expressed numerically and can be restored to the original XML data.

  Also, according to the XML data conversion apparatus of the first embodiment, the bit / depth combination unit multiplies the measured value of the node depth by n (n is an arbitrary natural number equal to or greater than 2), and is provided with a bit. In such a case, since a value obtained by adding 1 is output, table data that can be restored to the original XML data can be converted by a simple process.

  Further, according to the XML data conversion apparatus of the first embodiment, since the node type is a non-empty element, empty element, attribute, element text, attribute text, the most basic information unit in XML data. Can be converted to table data.

  In the XML data conversion apparatus according to the first embodiment, the first column of the two-column table is the name of the node of the XML document, and the second column is the structure of the node of the XML document, and the name and structure can be completely separated. Therefore, it is easy to operate the XML document. In addition, since the node type and the node depth are combined and shown in the second column, the amount of information as a table can be reduced. Note that the first and second columns in the table may be reversed.

  In addition, since the structure of the XML document can be held numerically, less memory is required for the operation of the XML document. Furthermore, since it can be stored in a single table, high-speed search is possible.

  In an XML document, a non-empty element needs to be described twice with a start tag and an end tag. However, once stored in a table, only one description is required. Therefore, the compression effect of the XML document itself can be expected by the number of elements excluding empty elements.

Further, according to the XML data restoring apparatus of the first embodiment, the XML data restoring apparatus restores the XML data from the table data including the identification information of each node of the XML data and the numerical value corresponding thereto. A bit / depth dividing unit that extracts a value indicating the type of node by the presence / absence of bit assignment and a value indicating the node depth when each node is represented by a tree structure, and the bit / depth Based on the value indicating the node depth extracted by the dividing unit, the tree structure restoring unit that restores the tree structure of the XML data, and the value of the node type extracted by the bit / depth dividing unit by the presence or absence of bit assignment A node type restoration unit that restores the type of each node indicated by the tree structure, and a node name assignment unit that assigns identification information to each node whose type has been restored by the node type restoration unit. Because it was example, it is possible to restore the XML data from the table data comprising the number corresponding to the identification information of each node.

  Also, according to the XML data restoration apparatus of the first embodiment, the bit / depth division unit obtains the remainder obtained by dividing the numerical value corresponding to the identification information of each node by n (n is an arbitrary natural number of 2 or more). Since the bit value and the quotient indicating the type of the node are extracted as the value indicating the depth of the node, it is possible to restore the table data to the original XML data with a simple process.

  Further, according to the XML data restoration apparatus of the first embodiment, since the node type is a non-empty element, empty element, attribute, element text, attribute text, the most basic information unit in XML data. It can be restored to XML data.

Embodiment 2. FIG.
In the first embodiment, the bit assigning unit 32 assigns the node type restoration bit off to the “attribute text”. However, the bit assigning unit 32 may assign the node type restoration bit on to the “attribute text”. That is, in the second embodiment, the fifth numerical value in the table of FIG. 4 is 9, and the fifth numerical value in the tree structure of FIG. In this case, the node type restoration unit 42 restores the original XML document by performing the following processing.

FIG. 7 is a flowchart showing restoration processing of the node type restoration unit 42 according to the second embodiment.
That is, when the bit is on (step ST71) and has a child node (step ST72), the node type restoration unit 42 has the node type “attribute”, the bit is on (step ST71), and has no child node. (Step ST72) If the parent node is an attribute (Step ST73), “attribute text”, the bit is on (Step ST71), has no child node (Step ST72), and the parent node is not an attribute (Step ST73). ) Is determined as “element text”. In addition, when the bit is off (step ST71) and has a child node (step ST74), “non-empty element”, and when the bit is off (step ST71) and has no child node (step ST74), “empty element” Is determined.

Hereinafter, the operation of the node type restoration unit 42 will be described by taking the case of FIGS. 4 and 5 in the above-described second embodiment as an example.
The first node is No in the conditional branch in step ST71 and Yes in the conditional branch in step ST74. The first node is a “non-empty element”.
The second node is No in the conditional branch of step ST71, No in the conditional branch of step ST74, and the second node is an “empty element”.

The third node is No in the conditional branch of step ST71 and Yes in the conditional branch of step ST74, and the third node is a “non-empty element”.
In the fourth node, Yes is determined in the conditional branch in Step ST71, and Yes is determined in the conditional branch in Step ST72. The fourth node is an “attribute”.
In the fifth node, Yes in the conditional branch in step ST71, No in the conditional branch in step ST72, Yes in the conditional branch in step ST73, and the fifth node is “attribute text”.
In the sixth node, Yes in the conditional branch in step ST71, No in the conditional branch in step ST72, No in the conditional branch in step ST73, and the sixth node is “element text”.

  The operations other than the bit assigning unit 32 and the node type restoring unit 42 described above are the same as those in the first embodiment, and thus the description thereof is omitted here.

  As described above, according to the XML data conversion device and the XML data restoration device of the second embodiment, the bit assignment unit assigns the node type restoration bit on to the “attribute text”, and the node type restoration unit uses this bit. Since the node type is restored based on “on”, the same effect as in the first embodiment can be expected also in the second embodiment.

Embodiment 3 FIG.
In the first embodiment, at the time of conversion from an XML document to a table, all of the node type restoration bits are turned off in the “attribute text” in the bit assigning unit 32. Further, in the second embodiment, when the XML document is converted into the table, all the node type restoration bits are set to “on” in the “attribute text” in the bit assigning unit 32. However, on and off of the node type restoration bit may be mixed in the “attribute text” in the bit assigning unit 32. That is, in the third embodiment, the fifth numerical value of the table of FIG. 4 is 8 or 9, and the fifth numerical value of the tree structure of FIG. 5 is a white circle number or a black circle number. In this case, the node type restoration unit 42 restores the original XML document by performing the following processing.

FIG. 8 is a flowchart showing restoration processing of the node type restoration unit 42 according to the third embodiment.
That is, when the bit is on (step ST81) and has a child node (step ST82), the node type restoration unit 42 has the node type “attribute”, the bit is on (step ST81), and has no child node. (Step ST82) If the parent node is an attribute (Step ST83), "attribute text", the bit is on (Step ST81), has no child nodes (Step ST82), and the parent node is not an attribute (Step ST83) ) Is determined as “element text”. The operations in these steps ST81 to ST83 are the same as the operations in steps ST71 to ST73 in the second embodiment.

  If the bit is off (step ST81), the parent node is not an attribute (step ST84), and has no child node (step ST85), it is “empty element”, the bit is off (step ST81), and the parent node is If it is not an attribute (step ST84) and has a child node (step ST85), "non-empty element", if the bit is off (step ST81) and the parent node is an attribute (step ST84), "attribute text" Is determined. That is, the operations in steps ST81 to ST85 are the same as the operations in steps ST61 to ST64 of the first embodiment.

Hereinafter, the operation of the node type restoration unit 42 will be described by taking the case of FIGS. 4 and 5 in the above-described third embodiment as an example.
In the first node, No in the conditional branch in step ST81, No in the conditional branch in step ST84, and Yes in the conditional branch in step ST85, the first node is an “non-empty element”.
In the second node, No in the conditional branch in step ST81, No in the conditional branch in step ST84, No in the conditional branch in step ST85, and the second node is an “empty element”.
The third node is No in the conditional branch in step ST81, No in the conditional branch in step ST84, No in the conditional branch in step ST85, and the third node is an “non-empty element”.

In the fourth node, the conditional branch in step ST81 is Yes, and in the conditional branch in step ST82, Yes, the fourth node is “attribute”.
In the fifth node, if the bit is on, the conditional branch in step ST81 is Yes, the conditional branch in step ST82 is No, the conditional branch in step ST83 is Yes, and the fifth node is “attribute text”. It is. If the bit is off, the condition branch of step ST81 is No, the condition branch of step ST84 is Yes, and it is determined as “attribute text”.
In the sixth node, Yes in the conditional branch in step ST81, No in the conditional branch in step ST82, No in the conditional branch in step ST83, and the sixth node is “element text”.

  The operations other than the bit assigning unit 32 and the node type restoring unit 42 described above are the same as those in the first embodiment, and thus the description thereof is omitted here.

  As described above, according to the XML data conversion device and the XML data restoration device of the third embodiment, the node type restoration unit mixes the node type restoration bit on and off in the “attribute text” in the bit assignment unit. Then, since the node type is restored based on these bit values, the same effect as in the first embodiment can be expected also in the third embodiment.

  In the first and second embodiments, the method of assigning the node type restoration bit on / off in the bit assigning unit 32 can be completely reversed. Further, in the third embodiment, it is possible to completely reverse the method of giving the node type restoration bit on / off in the bit granting unit 32 to the nodes excluding “attribute text”.

  In the first embodiment, the bit assigning unit 32 assigns the node type restoration bit off to the nodes of “attribute” / “element text”, and “non-empty element” / “empty element” / “attribute text”. The node type restoration bit on can also be given to the node "." In this case, Yes and No are switched in the conditional branch step ST61 of the flowchart of FIG.

  In the second embodiment, the bit assigning unit 32 assigns the node type restoration bit off to the nodes of “attribute”, “element text”, and “attribute text”, and “non-empty element” / “empty element”. The node type restoration bit on can also be given to the node "." In this case, Yes and No are switched in the conditional branch step ST71 of the flowchart of FIG.

  In the third embodiment, the bit assigning unit 32 assigns the node type restoration bit off to the nodes of “attribute” and “element text”, and to the nodes of “non-empty element” and “empty element”. A node type restoration bit on can also be given. A node type restoration bit on may be assigned to a node of “attribute text”, or a node type restoration bit off may be given. In this case, Yes and No are switched in the conditional branch step ST81 of the flowchart of FIG.

  Even when the node type restoration bit is added as described above, the same effect as in the first embodiment can be expected.

Embodiment 4 FIG.
In the first to third embodiments, the node depth measurement unit 33 may obtain the rank of appearance of the parent node of each node instead of the depth of each node. However, 0 is obtained when the own node is the root node and there is no parent node. In this case, if the parent node of the own node is known, the tree structure restoring unit 43 can restore the tree structure as shown in FIG.

The operation of the node depth measurement unit 33 in the fourth embodiment will be described using the XML document shown in FIG. 2 as an example.
In the aaa node, since aaa is the parent node, the node depth measuring unit 33 obtains 0.
In the node of bbb, since the appearance rank of the parent node aaa is first, the node depth measurement unit 33 obtains 1.
In the ccc node, since the appearance rank of the parent node aaa is first, the node depth measurement unit 33 obtains 1.
In the node of ddd, since the appearance rank of the parent node ccc is third, the node depth measurement unit 33 obtains 3.
In the eee node, since the appearance rank of the parent node ddd is fourth, the node depth measurement unit 33 obtains 4.
In the node of fff, since the appearance rank of the parent node ccc is third, the node depth measurement unit 33 obtains 3.

  Further, the tree structure restoration unit 43 restores the tree structure from the appearance order of the parent node of each node, using these values as alternatives to the depth of each node.

  As described above, according to the XML data conversion apparatus of the fourth embodiment, the node depth measurement unit outputs the appearance rank of the parent node of each node as an alternative to the depth of each node, According to the XML data restoration device, the tree structure restoration unit restores the tree structure from the appearance order of the parent node of each node as an alternative to the depth of each node, and thus the same effect as in the first embodiment. Can be expected.

Embodiment 5. FIG.
In the first to fourth embodiments, the bit type and the node depth are combined by the bit / depth combining unit 34 to obtain the values in the second column of the table. The bit value of the assigning unit 32 and the numerical value of the node depth may be used as values in a table of three columns, which will be described as a fifth embodiment.

  Here, the configurations of the XML data conversion device and the XML data restoration device are the same as those in FIG. 1 except that the bit / depth combination unit 34 and the bit / depth division unit 44 are not provided. explain.

FIG. 9 is an explanatory diagram of a table created by the XML data conversion apparatus according to the fifth embodiment.
This is obtained by converting the XML document shown in FIG. 2 into table data by the conversion unit 30 and corresponds to the table data of FIG. 4 in the first embodiment. Here, the first column shows the name of the node, the second column shows the on / off of the bit given by the bit assigning unit 32, and the third column shows the depth of each node measured by the node depth measuring unit 33. Is shown. In FIG. 9, “*” in the fourth and sixth lines indicates the bit on.

  Further, as the operation of the restoration unit 40, the tree structure restoration unit 43 restores the tree structure based on the values in the third column of the table data shown in FIG. 9, and the node type restoration unit 42 sets the bit in the second column. The node type is restored by on / off. The operation for restoring the node type in this case is performed in the same manner as in the first embodiment.

As described above, according to the XML data conversion apparatus of the fifth embodiment, the XML data is represented by the identification information of each node of the XML data, the value indicating the type of the corresponding node, and each node in a tree structure. An XML data conversion device for converting into table data composed of numerical values indicating node depths when represented, a node name extraction unit for extracting identification information of each node from XML data, and depending on the type of each node When a bit is assigned only to a predetermined type of node and output as a value indicating whether or not a bit is assigned to each node, and when each node is represented by a tree structure Since it has a node depth measurement unit that outputs a numerical value corresponding to the node depth, it does not require a schema to generate table data, and can be restored to the original XML data Una it is possible to convert a single table data, it is possible to simplify the conversion process.

Further, according to the XML data restoration apparatus of the fifth embodiment, the identification information of each node of the XML data, the value indicating the type of the corresponding node, and the node depth when each node is represented by a tree structure An XML data restoration device for restoring XML data from table data consisting of a numerical value indicating a tree structure restoring unit for restoring a tree structure of XML data based on a numerical value indicating a node depth, and a bit of a node type Based on the value indicated by the presence / absence of assignment, a node type restoration unit that restores the type of each node indicated by the tree structure, and identification information is assigned to each node whose type has been restored by the node type restoration unit Since the node name assigning unit is provided, the XML data can be restored from the table data composed of the identification information of each node and the numerical value corresponding thereto, and the restoration process is simplified. It can be.

It is a block diagram which shows the XML data converter and XML data decompression | restoration apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows an example of an XML document. It is explanatory drawing which shows the tree structure of the XML document shown in FIG. It is explanatory drawing of the table which converted the XML document shown in FIG. It is explanatory drawing which shows the tree structure decompress | restored from the table of FIG. 6 is a flowchart illustrating an operation for determining a node type according to the first embodiment. 10 is a flowchart illustrating an operation for determining a node type according to the second embodiment. 12 is a flowchart illustrating an operation for determining a node type according to the third embodiment. FIG. 20 is an explanatory diagram of a table in the fifth embodiment.

Explanation of symbols

  10 XML document storage section, 20 table storage section, 30 conversion section, 31 node name extraction section, 32 bit assignment section, 33 node depth measurement section, 34 bit / depth combination section, 40 restoration section, 41 node name assignment section 42 node type restoration unit, 43 tree structure restoration unit, 44 bit / depth division unit.

Claims (9)

An XML data conversion device that converts XML data into table data composed of identification information of each node of the XML data and a numerical value corresponding to the identification information,
A node name extraction unit that extracts identification information of each node from the XML data;
According to the type of each of the nodes, a bit granting unit that gives a bit only to a predetermined type of node and does not give a bit to other types of nodes ;
A node depth measurement unit for measuring a node depth when each node is represented by a tree structure;
Based on the presence / absence of bit assignment provided by the bit assignment unit and the node depth measured by the node depth measurement unit, the measured value of the node depth is n (n is an arbitrary natural number of 2 or more). XML data provided with a bit / depth combination unit that doubles and generates a numerical value to which 1 is added when a bit is added and outputs the numerical value as a numerical value corresponding to the identification information of each node Conversion device. The XML data is converted into table data including identification information of each node of the XML data, a value indicating the type of the corresponding node, and a numerical value indicating the node depth when each node is represented by a tree structure. An XML data conversion device for converting,
A node name extraction unit that extracts identification information of each node from the XML data;
Bit assignment that assigns a bit only to a predetermined type of node according to the type of each node and outputs whether or not a bit is assigned to each node as a value representing the type of the node And
An XML data conversion device comprising: a node depth measuring unit that outputs a numerical value corresponding to a node depth when each node is represented by a tree structure. The XML data conversion apparatus according to claim 1 or 2 , wherein the node type is a non-empty element, an empty element, an attribute, an element text, or an attribute text. The XML data according to any one of claims 1 to 3 , wherein the node depth measurement unit outputs an appearance rank of a parent node of each node as an alternative to the depth of each node. Conversion device. An XML data restoration device for restoring XML data from table data comprising identification information of each node of XML data and a numerical value corresponding to the identification information,
A bit / depth dividing unit that extracts a value indicating the type of the node by the presence or absence of bit assignment and a value indicating the node depth when each node is represented by a tree structure, from a numerical value corresponding to each node;
A tree structure restoration unit for restoring the tree structure of the XML data based on the value indicating the node depth extracted by the bit / depth division unit;
A node type restoration unit that restores the type of each node indicated by the tree structure based on a value indicating whether or not a bit is provided with a node type extracted by the bit / depth division unit;
An XML data restoration apparatus comprising: a node name assigning unit that assigns the identification information to each node whose type is restored by the node type restoring unit. The bit / depth dividing unit divides a numerical value corresponding to the identification information of each node by n (n is an arbitrary natural number of 2 or more), a bit value indicating the type of the node, and a quotient as the depth of the node. 6. The XML data restoration device according to claim 5 , wherein the XML data restoration device extracts the value as the indicated value. XML for restoring XML data from table data comprising identification information of each node of XML data, a value indicating the type of node corresponding to the node, and a numerical value indicating the node depth when each node is represented by a tree structure A data restoration device,
A tree structure restoration unit for restoring the tree structure of the XML data based on the numerical value indicating the node depth;
A node type restoration unit that restores the type of each node indicated by the tree structure based on a value indicating whether or not the node is provided with a bit ;
An XML data restoration apparatus comprising: a node name assigning unit that assigns the identification information to each node whose type is restored by the node type restoring unit. The node type, the element is not empty, an empty element, attributes, elements of text, XML data restoration device according to any one of claims 7 claim 5, which is a text attribute. Tree structure restorer as an alternative to depth of each node, according to any one of claims 8 to restore the tree structure from claim 5, wherein the appearance order of the parent node of each node XML data restoration device.

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