Abstract:
In a data linking method of extracting data of a host data base on a computer into a portable remote terminal, an item definition data base which defines a record attribute, an object storage data base which stores object data on a record basis, a relation definition data base which defines relations among object data and a definition data base which defines relations among the respective data bases, and conducts synchronous processing of writing. The portable remote terminal conducts link data solution processing based on a record attribute of the item definition data base when a record item of the object storage data base refers to other object storage data base, and changes, when the display order of object data of the object storage data base is changed or when existence/non-existence of display is selected, the display order of object data of said item definition data base or an attribute indicative of existence/non-existence of display according to the contents of the change or the selection, and the computer further reads an updated record from said object storage data base of the portable remote terminal to update the host data base.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a system for linking data between a computer and a portable remote terminal and a data linking method therefor and, more particularly, to a system for linking data between a computer and a portable remote terminal enabling data extracted from a personal computer into a portable remote terminal to be edited and applied freely and a data linking method therefor. 
     2. Description of the Related Art 
     In recent years, more and more cases occur in business etc. where various information in a data base on a computer at an office is brought out by a portable remote terminal to user&#39;s destination and is made the most of. Conducted, for example, are bringing out customer&#39;s information into a portable remote terminal and referring to/editing the information, or bringing information of a product of outside trade into a portable remote terminal and referring to the information, or bringing out information about business negotiations that a user currently has into a portable remote terminal and making the most of the information. 
     In a case where data on a data base of a personal computer is read into a portable remote terminal and the portable remote terminal is brought to a user&#39; destination to use the data, when a volume of data is large, much time is conventionally cost for the processing of extracting data from the personal computer into the portable remote terminal and the processing of synchronizing the terminal with the personal computer which is conducted when data editing is executed on the portable remote terminal because the data in the personal computer is taken in as it is into the portable remote terminal. 
     Also in conventional systems, data in a data base is taken in as it is into a portable remote terminal to result in bringing out data that needs not to be brought out by the portable remote terminal as well, which hinders operation and application when necessary data is actually referred to by the portable remote terminal. 
     Among conventional art related to data link between computers are, for example, distributed data base management systems disclosed in Japanese Patent Laying-Open (Kokai) No. Heisei 8-305714 and Japanese Patent Laying-Open (Kokai) No. Heisei 2-58165. 
     Disclosed in Japanese Patent Laying-Open (Kokai) No. Heisei 5-89004 is a technique of downloading a data base of a host computer into a portable remote terminal and uploading data updated offline by the portable remote terminal into the host computer in synchronization with the host computer. 
     The above-described conventional data link between a personal computer and a portable remote terminal has such problems as set forth below. 
     First, since data on the personal computer is taken in into the portable remote terminal as it is, when a volume of data is large, much time is cost for the processing of extracting data from the personal computer into the portable remote terminal and the processing of synchronizing the terminal with the personal computer which is conducted when data edging is executed on the portable remote terminal. 
     Secondly, in a conventional system, data in a data base is taken in into a portable remote terminal as it is to result in bringing out data that needs not to be brought out by the portable remote terminal as well, which hinders quick application of data when necessary data is actually referred to by the portable remote terminal. 
     Thirdly, since data taken in into a portable remote terminal should be synchronized with a host data base on a computer, the order of items of data on the portable remote terminal can not be changed by a user as required. This prevents efficient use of data. 
     Although Japanese Patent Laying-Open (Kokai) No. Heisei 5-89004 discloses a system of downloading a data base of a host computer into a portable remote terminal and uploading data updated offline by the portable remote terminal into the host computer in synchronization with the host computer, the system only provides synchronization of the data updated on the portable remote terminal based on user ID and fails to solve none of the above-described problems. 
     Also, the distributed data base management systems disclosed in the above-described Japanese Patent Laying-Open (Kokai) No. Heisei 8-305714 and Japanese Patent Laying-Open No. 2-58165 relate to a technique of providing synchronization of data bases dispersedly arranged at a plurality of sites connected through LAN, they recite none of a technique of bringing out a data base on a computer into a portable remote terminal to conduct reference/editing and synchronous processing as well. 
     SUMMARY OF THE INVENTION 
     A first object of the present invention is to provide a system for linking data between a personal computer and a portable remote terminal which enables execution of the processing of extracting data from the personal computer into the portable remote terminal and the processing of synchronizing the portable remote terminal with the personal computer in a short time period, and a data linking method therefor. 
     A second object of the present invention is to provide a system for linking data between a personal computer and a portable remote terminal which realizes quick application of data by selectively taking in data that needs to be brought out from a data base of the computer by the portable remote terminal, and a data linking method therefor. 
     A third object of the present invention is to provide a system for linking data between a personal computer and a portable remote terminal which enables the order of items of data taken in into the portable remote terminal to be changed by a user as required, thereby realizing efficient use of data, and a data linking method therefor. 
     According to the first aspect of the invention, a system for linking data between a computer and a portable remote terminal which extracts data of a host data base on the computer into the portable remote terminal, displays and edits the extracted data on the portable remote terminal and conducts synchronous processing of updated data in the portable remote terminal and a data base in the computer, wherein 
     the computer comprissing 
     means for selecting object data to be brought out from the host data base into the portable remote terminal and a record item of the object data, 
     means for creating on the portable remote terminal, with respect to selected object data, an item definition data base which defines a record attribute, an object storage data base which stores object data on a record basis correspondingly to the item definition data base, a relation definition data base which defines relations among object data stored in the object storage data base and a definition data base which defines relations among the respective data bases created, 
     means for writing, on the basis of a record taken out from the host data base, data into the corresponding one of the object storage data bases according to the item definition data base, and 
     synchronization means for conducting synchronous processing of reading updated data from the object storage data base of the portable remote terminal and writing the data into the host data base of the computer, and 
     the portable remote terminal comprising 
     means for conducting, when a record item of the object storage data base refers to other the object storage data base, link data solution processing based on a record attribute of the item definition data base, and 
     means for changing, when the display order of object data of the object storage data base is changed or when existence/non-existence of display is selected, the display order of object data of the item definition data base or an attribute indicative of existence/non-existence of display according to the contents of the change or the selection, and wherein 
     the synchronization means of the computer reads an updated record from the object storage data base of the portable remote terminal to update the host data base of the computer. 
     In the preferred construction, the portable remote terminal further comprises updating flag setting means for setting, when updating or addition of a record is made of the object storage data base, an updating flag at the corresponding record of the object storage data base. 
     In another preferred construction, the portable remote terminal further comprises editing means for editing object data stored in the object storage data base and conducting change of the display order of data items or selection of existence/non-existence of display. 
     In another preferred construction, the portable remote terminal further comprises updating flag setting means for setting, when updating or addition of a record is made of the object storage data base, an updating flag at the corresponding record of the object storage data base, and wherein the updating flag setting means, when updating or addition of a record is made of the object storage data base, sets a flag indicating that the object storage data base in question is updated at the definition data base, and the synchronization means searches the object storage data base updated by a flag of the definition data base and reads a record at which the object storage data base updating flag searched is set to update the host data base of the computer. 
     In another preferred construction, for each record item, the item definition data base has, as attributes, other object storage data base to be referred to by the record item in question and a record item, a record item with which the record item in question links, and a record item of an object storage data base to be referred to by the linked record item. 
     According to the second aspect of the invention, a method of linking data between a computer and a portable remote terminal which extracts data of a host data base on the computer into the portable remote terminal, displays and edits the extracted data on the portable remote terminal and conducts synchronous processing of updated data in the portable remote terminal and a data base in the computer, comprising 
     the steps of the computer of: 
     with respect to object data to be brought out into the portable remote terminal which is selected from the host data base and a record item of the object data, creating, on the portable remote terminal, an item definition data base which defines a record attribute, an object storage data base which stores object data on a record basis correspondingly to the item definition data base, a relation definition data base which defines relations among object data stored in the object storage data base and a definition data base which defines relations among the respective data bases created, 
     on the basis of a record taken out from the host data base, writing data into the corresponding one of the object storage data bases according to the item definition data base, and 
     conducting synchronous processing of reading updated data from the object storage data base of the portable remote terminal and writing the data into the host data base of the computer, 
     the steps of the portable remote terminal of: 
     when a record item of the object storage data base refers to other the object storage data base, conducting link data solution processing based on a record attribute of the item definition data base, and 
     when the display order of object data of the object storage data base is changed or when existence/non-existence of display is selected, changing the display order of object data of the item definition data base or an attribute indicative of existence/non-existence of display according to the contents of the change or the selection, and 
     the step of the computer of reading an updated record from the object storage data base of the portable remote terminal to update the host data base of the computer. 
     In the preferred construction, the method of linking data between a computer and a portable remote terminal further comprising 
     the step of the portable remote terminal of, 
     when updating or addition of a record is made of the object storage data base, setting an updating flag at the corresponding record of the object storage data base. 
     In another preferred construction, the method of linking data between a computer and a portable remote terminal further comprising 
     the steps of the portable remote terminal of: 
     when updating or addition of a record is made of the object storage data base, setting an updating flag at the corresponding record of the object storage data base and further setting a flag indicating that the object storage data base in question is updated at the definition data base, wherein 
     in synchronous processing of the computer, the object storage data base updated by a flag of the definition data base is searched and a record at which the object storage data base updating flag searched is set is read to update the host data base of the computer. 
     According to another aspect of the invention, a computer readable memory which stores a program for linking data between a computer and a portable remote terminal which extracts data of a host data base on the computer into the portable remote terminal, displays and edits the extracted data on the portable remote terminal and conducts synchronous processing of updated data in the portable remote terminal and a data base in the computer, wherein 
     the data link program comprises the steps of: 
     on the side of the computer 
     with respect to object data to be brought out into the portable remote terminal which is selected from the host data base and a record item of the object data, creating, on the portable remote terminal, an item definition data base which defines a record attribute, an object storage data base which stores object data on a record basis correspondingly to the item definition data base, a relation definition data base which defines relations among object data stored in the object storage data base and a definition data base which defines relations among the respective data bases created, 
     on the basis of a record taken out from the host data base, writing data into the corresponding one of the object storage data bases according to the item definition data base, and 
     conducting synchronous processing of reading updated data from the object storage data base of the portable remote terminal and writing the data into the host data base of the computer, 
     on the side of the portable remote terminal 
     when a record item of the object storage data base refers to other the object storage data base, conducting link data solution processing based on a record attribute of the item definition data base, and 
     when the display order of object data of the object storage data base is changed or when existence/non-existence of display is selected, changing the display order of object data of the item definition data base or an attribute indicative of existence/non-existence of display according to the contents of the change or the selection, and 
     on the computer, reading an updated record from the object storage data base of the portable remote terminal to update the host data base of the computer. 
     Other objects, features and advantages of the present invention will become clear from the detailed description given herebelow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only. 
     In the drawings: 
     FIG. 1 is a diagram showing system structure of a data link system for linking data between a personal computer and a portable remote terminal according to an embodiment of the present invention; 
     FIG. 2 is a diagram showing program module structure of the personal computer and the portable remote terminal realizing the data link system of the present invention; 
     FIG. 3 is a diagram showing each program of the personal computer and the portable remote terminal of the present invention and arrangement of a generated DB in the portable remote terminal; 
     FIG. 4 is a diagram showing table arrangement of a data base definition DB in the DB on the portable remote terminal of the present invention; 
     FIG. 5 is a diagram showing table arrangement of an item definition DB in the DB on the portable remote terminal of the present invention; 
     FIG. 6 is a diagram showing table arrangement of a relation definition DB in the DB on the portable remote terminal of the present invention; 
     FIG. 7 is a diagram showing table arrangement of a user&#39;s selection item DB in the DB on the portable remote terminal of the present invention; 
     FIG. 8 is a diagram showing table arrangement of an object storage DB in the DB on the portable remote terminal of the present invention; 
     FIG. 9 is a flow chart for use in explaining the contents of initialization processing by an application program of the personal computer of the present invention; 
     FIG. 10 is a flow chart for use in explaining the contents of the processing of synchronizing the personal computer and the portable remote terminal of the present invention; 
     FIG. 11 is a diagram showing an example of display screen on which a user selects the order of data items to be displayed in data editing on the portable remote terminal of the present invention; 
     FIG. 12 is a diagram showing an example of data editing screen on the portable remote terminal of the present invention; 
     FIG. 13 is a diagram showing an example of data editing screen on the portable remote terminal of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiment of the present invention will be discussed hereinafter in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instance, well-known structures are not shown in detail in order to unnecessary obscure the present invention. 
     FIG. 1 is a diagram showing system structure of a data link system for linking data between a personal computer and a portable remote terminal according to the embodiment of the present invention. 
     The data link system is structured to have a personal computer  10  and a portable remote terminal  11  connected through a connection cable  12 , thereby enabling data transmission and reception between the computer and the terminal.  13  denotes an input means (pen) for performing data editing (display and input) on the portable remote terminal  11 . The portable remote terminal  11  arbitrarily extracts part of data of a data base (DB) in the personal computer  10  to edit data (display/modification/input). 
     FIG. 2 is a diagram showing program module structure of the personal computer  10  and the portable remote terminal  11  realizing the data link system of the present invention. The program module of the personal computer  10  is composed of an operating system A 20  and an application program A 21  and has a host DB  22 . The program module of the portable remote terminal  11  is composed of an operating system B 30  and an application program B 31  and has a DB  40 . 
     Control for sending and receiving DB data is given by the operating system A 20  and the operating system B 30 . An arrow PO indicates a direction of program control made when the DB 40  is accessed by the application program A 21  of the personal computer  10 . 
     FIG. 3 shows each program of the personal computer  10  and the portable remote terminal  11  and DB arrangement of the generated DB 40  in the portable remote terminal  11 . 
     As illustrated in the figure, the DB 40  of the portable remote terminal  11  is composed of a data base definition DB 41 , an item definition DB 42 , a relation definition DB 43 , a user&#39;s selection item DB 44  and an object storage DB ( 45   a ,  45   b ,  45   c , . . .  45   n ). 
     Display and editing on the portable remote terminal  11  are executed with respect to data within the DB  40  by the application program B 31 . FIG. 11 shows an example of a display screen  210  on which a user selects the order of data items to be displayed in data editing (display/input) conducted by the application program B 31  on the portable remote terminal  11 . FIGS. 12 and 13 each show an example of a screen for data editing conducted on the portable remote terminal  11  by the application program B 31  of the portable remote terminal  11 . 
     FIGS. 4 to  8  show structure of the DB 40  on the portable remote terminal  11 . 
     FIG. 4 is a diagram showing table arrangement of the data base definition DB 41  of FIG.  3 .  41 - 1 ˜ 41 - 4  each show a column of the data base definition DB 41 .  411 ˜ 416  denote records where data is stored. 
     FIG. 5 is a diagram showing table arrangement of the item definition DB 42  of FIG.  3 .  42 - 1 ˜ 42 - 13  each show a column of the item definition DB 42 .  421 ˜ 425  denote records where data is stored. 
     FIG. 6 is a diagram showing table arrangement of the relation definition DB 43  of FIG.  3 .  43 - 1 ˜ 43 - 3  each denote a column of the relation definition DB 43 . 
     FIG. 7 is a diagram showing table arrangement of the user&#39;s selection item DB 44  of FIG.  3 .  44 - 1 ˜ 44 - 3  each denote a column of the user&#39;s selection item DB 44 . 
     FIG. 8 is a diagram showing table arrangement of the object storage DBs  45   a ,  45   b ,  45   c , . . . ,  45   n .  45 - 1 ˜ 45 - 10  each denote a column of the object storage DB 45 . The object storage DB 45   a  represents an object storage DB of a company indicated by the record  415  of the data base definition DB 41 , while the object storage DB 45   b  represents an object storage DB of a product indicated by the record  416  of the data base definition DB 41 . 
     Detailed description will be here made of functions and table arrangement of the above-described DB 40  on the portable remote terminal  11 . 
     (a) Data Base Definition DB 41   
     The record  411  represents information of user ID (description of “ 123 ” here denotes the number of user ID), the record  412  represents the item definition DB 42 , the record  413  represents the relation definition DB 43 , the record  414  represents the user&#39;s selection item DB 44 , and the records  415  and  416  define relations of various data bases of the object storage DBs 45   a  and  45   b . The data base definition DB 41  exists only one within the portable remote terminal  11 . 
     In the data base definition DB 41  of FIG. 4, a DB name  41 - 1  represents a name or a user ID which unitarily identifies a data base. A DB attribute  41 - 2  represents a data base attribute. Here, DB_USERID is an attribute indicative of a user ID, DB_DEFINE is an attribute indicative of the item definition DB, DB_RELATE is an attribute indicative of the relation definition DB, DB_CHOICE is an attribute indicative of the user&#39;s selection item DB and DB_RECORD is an attribute indicative of the object storage DB. 
     A synchronization time and date  41 - 3  represents a time stamp when synchronous processing of a data base is conducted. A DB updating flag  41 - 4  is a flag of a data base to be updated which represents an object not to be synchronized as “0” and an object to be synchronized as “1”. 
     (b) Item Definition DB 42   
     The item definition DB 42  defines an attribute of a record item. Definitions corresponding to all the object storage DBs 45  are stored. The DB 42  exists only one within the portable remote terminal  11 . 
     In the item definition DB 42  of FIG. 5, a DB name  42 - 1  represents a DB name of the object storage DB 45 . An item name  42 - 2  represents a record item name and corresponds to the columns  45 - 1  to  45 - 10  of the object storage DB 45 . 
     A data type  42 - 3  represents a data type of a record item and a control attribute. DT_TEXT denotes text edit, DT_MEMO denotes memory edit, DT_INT denotes integer edit, DT_ID denotes record ID edit, DT_CURRENCY denotes currency edit, DT_FLOAT denotes floating point edit, DT_BOOL denotes logical value check box, DT_DATE denotes date edit, DT_TIME denotes time edit, DT_TIMESTAMP denotes time stamp edit, DT_CHOICE denotes choice drop down list, DT_CMB denotes combo drop down (edit combo), DT_LINK denotes link field drop down list and DT_FLAG denotes flag edit. 
     A control attribute  42 - 4  represents a control attribute of a record item. Here, IP_HEADER denotes a record header (not displayed), IP_NORMAL denotes normal edit, IP_MUST denotes input must and IP_STATIC denotes edit disabled. An item width  42 - 5  represents a display size of a record item. 
     A reference DB name  42 - 6  represents a name of a DB to be referred to such as combo, choice and link. 
     Here, DT_CMB represents a name of the user&#39;s selection item DB 44 , DT_CHOICE represents a name of the user&#39;s selection item DB 44  and DT_LINK represents a name of the object storage DB 45 . A reference key  42 - 7  represents a key for use in obtaining a record from a reference DB. Here, DT_CMB denotes a key name of the user&#39;s selection item DB 44 , DT_CHOICE denotes a key name of the user&#39;s selection item DB 44  and DT_LINK denotes an item name of the object storage DB 45 . 
     A link destination item name  42 - 8  represents a correlated DT_LINK item name. A reference item name  42 - 9  represents a reference item name in a DB referred to by a DT_LINK item. 
     A list display order  42 - 10  represents the item display order selected in the list display, in which 0 denotes that no item is displayed and an integer not less than  1  indicates the display order number (integer). A card display order  42 - 11  represents the item display order selected in the card display, in which 0 denotes that no item is displayed and an integer not less than 1 indicates the display order number (integer). 
     A record index  42 - 12  represents an index to each column of a record of the object storage DB 45  in question. Index exists only for an item that a user has brought out. An updating flag  42 - 13  is a flag of a record to be updated which represents an object not to be synchronized as 0 and an object to be synchronized as 1. 
     (c) Relation Definition DB 43   
     The relation definition DB 43  defines relations such as detailed/link destination corresponding to the object storage DB 45 . Definitions corresponding to all the object storage DBs 45  are stored. The relation definition DB 43  exists only one within the portable remote terminal  11 . 
     A host DB name  43 - 1  represents a top-level object storage DB name which is a DB name of the object storage DB 45  as a host. A detailed DB name  43 - 2  denotes a second-level object storage DB name which is a detailed DB name that can be displayed with respect to the host object storage DB 45 . A link destination detailed DB item name  43 - 3  represents an item name of a detailed DB where a record ID of a host DB is stored. 
     (d) User&#39;s Selection Item DB 44   
     The user&#39;s selection item DB 44  defines the contents of a combo item and a choice item. The DB exists only one within the portable remote terminal  11 . 
     A key name  44 - 1  represents a key which identifies a record group. The key name is used in the reference key  42 - 7  of the item definition DB 42 . An item value  44 - 2  represents an item value within the group and corresponds to a record value in the choice item. An item contents  44 - 3  represents item contents which correspond to those in the combo item. 
     (e) Object Storage DB 45   
     The DBs exist in the plural within the portable remote terminal  11 . The DBs exist as many as the number of objects to be linked with the personal computer  10 . 
     A serial ID 45 - 1  represents a record ID in a data base on the side of the portable remote terminal  11  which is sequentially applied at the time of the synchronous processing. At the time of new addition, the ID is applied to the end as a serial number. At the time of deletion, the ID has a blank. A record ID 45 - 2  represents a record ID on the side of the personal computer  10  which is not changed on the side of the portable remote terminal  11 . A time stamp  45 - 3  represents a time stamp of a record on the side of the personal computer  10 . The time stamp is not changed on the side of the portable remote terminal  11 . At the time of new creation, the time stamp has a blank. 
     An updating flag  45 - 4  is a flag of a record to be updated which represents an object not to be synchronized as 0 and an object to be synchronized as 1. Items  45 - 5  to  45 - n  represent record item contents values (n exist as many as the number of items which a user will bring out). 
     Next, initialization processing, downloading of host DB data, data editing on a portable remote terminal, synchronous processing of data and editing of a data display item in thus structured data link system of the present invention will be outlined with reference to the drawings. 
     (1) Initialization Processing 
     As the initialization processing, the application program A 21  of the personal computer  10  generates a DB set forth below as the setting of a DB link item. The following initialization processing is executed by user&#39;s instructions to the application program A 21 . FIG. 9 shows a flow chart of the initialization processing. 
     On the personal computer  10 , prepare a table of data which might be taken out into the portable remote terminal  11  and a table of field information and select business object data which will be taken out by a user and its record item based on the information (Step  901 ). The selection of business object data to be taken out and its record item is conducted by the user&#39;s operation of the application program A 21 . 
     Then, based on the information, create the item definition DB 42  which defines a record attribute (Step  902 ). 
     According to the contents of the created item definition DB 42 , create an individual object storage DB ( 45   a ,  45   b ,  45   c , . . . ,  45   n ) region (Step  903 ). 
     Next, create the relation definition DB 43  which defines relations such as detailed/link destination corresponding to the created object storage DB ( 45   a ,  45   b ,  45   c , . . . ,  45   n ) from the item definition DB 42  (Step  904 ). 
     Furthermore, when an alternative item data region exists within the object storage DB ( 45   a ,  45   b ,  45   c ,  45   n ), create a region of the user&#39;s selection item DB 44  (Step  905 ). Each of the created DBs is managed by the data base definition DB 41  which is created for defining a relation of a DB every time the DB is created (Step  906 ). 
     Next, download the data of the host DB 22  into the portable remote terminal  11  (Step  907 ). Downloading of the data of the host DB 22  is conducted by the application program A 21 . On the basis of a record taken out from the host DB 22  and according to the contents of a record attribute of the item definition DB 42 , write data into the corresponding object storage DBs  45   a  to  45   n  (Step  907 ). 
     (2) Data Editing on the Portable Remote Terminal 
     Editing work of data taken in into the portable remote terminal  11  is conducted by the application program B 31 . FIGS. 12 and 13 each show a data editing screen on the portable remote terminal  11 . 
     In FIG. 12, displayed in the list are a company name  501 , a telephone number  502  and a facsimile (facsimile number)  503 . 
     In FIG. 13, displayed in the card are information regarding one of the companies listed in FIG. 12 (company name  601 , how to read  602 , address (metropolis/prefecture, city/ward)  603 , telephone number  604 , facsimile  605 , relation  606 ). 
     On the list display of FIG. 12, by pressing (double tap) down a line in which data of the company name  501 , the telephone number  502  and the facsimile  503  is displayed with the pen  13  as an input means of the portable remote terminal  11 , a selected record is displayed in the card to allow editing of each field. 
     (3) Synchronous Processing 
     The processing of synchronizing the host DB 22  of the personal computer  10  and the DB 40  of the portable remote terminal  11  is executed by the application program A 21 . Conducted here is reading the DB 40  on the portable remote terminal  11  by the personal computer  10  to write the data into the host DB 22  in the personal computer  10 . In other words, write a record newly added/updated into the host DB 22 . In addition, set a link field between tables to a correct record ID to solve link information. This synchronous processing is automatically executed by the application program A 21  upon connection of the portable remote terminal  11  to the personal computer  10 . The processing is also executed by an instruction from the portable remote terminal  11 . 
     In the following, the synchronous processing by the application program A 21  will be described with reference to the flow chart of FIG.  10 . 
     Solution of link data on the portable remote terminal  11  (Step  1001 ). 
     In the program of the application program B 31  of the portable remote terminal  11 , such link data solution processing as set forth below is conducted prior to the synchronous processing. This link data solution processing is automatically executed by the application program B 31 . The present processing is usually conducted also in the screen editing processing by the application program B 31 . 
     In the following, description will be made of solution of a link between records and reference to a record. 
     According to the data type  42 - 3  of the record  422  of the item definition DB 42 , an attribute of the item  5  ( 45 - 9 ) of the record  451  of the object storage DB 45   a  (company) is a link field. In this case, since the reference DB name  42 - 6  indicates “product” to link with the object storage DB 45   b  (product), according to the contents “1” of the item  5  ( 45 - 9 ) of the record  451  of the object storage DB 45   a  (company), the record  452  of the object storage DB 45   b  (product) whose serial ID is “1” is supposed to link with the record  452 . Furthermore, since the reference key  42 - 7  indicates “product name”, the contents of the item  1  ( 45 - 5 ) of the record  452  of the object storage DB 45   b  (product) will be referred to by the record index  42 - 12 . 
     As to an attribute of the item  6  ( 45 - 10 ) of the record  451  of the object storage DB 45   a  (company), according to the link destination item name  42 - 8  and the reference item name  42 - 9  of the record  423  of the item definition DB 42 , the contents of the reference item name  42 - 9  of the reference DB indicated by the link destination item name  42 - 8  will be referred to. With the link destination item name  42 - 8  indicating “line of trade”, a field of a link destination indicated by the reference DB name  42 - 6  (product) and the reference key  42 - 7  (product name) of the record  422  will be referred to. Also, since the item  5  ( 45 - 9 ) of the record  451  of the object storage DB 45   a  (company) indicates “1”, price of the record  452  of the object storage DB 45   b  (product) whose serial ID is “1” will be referred to and in the item  6  ( 45 - 10 ) of the record  451  of the object storage DB 45   a  (company), “10000” is stored as real data. 
     As the premise for conducting synchronous processing, updating flag setting processing is conducted in screen editing processing by the application program B 31 . Updating flags exist in the data base definition DB 41  and the item definition DB 42 , and the object storage DB 45 . The DB updating flag  41 - 4  of the data base definition DB 41  is set up when updating or addition is made of the managed data base. The updating flag  42 - 13  of the item definition DB 42  is set up when the contents of the item width  42 - 5 , the list display order  42 - 10  and the card display order  42 - 11  are modified. The updating flag  45 - 4  of the object storage DB is set up when a record is updated. 
     Transfer only the modified data from the portable remote terminal  11  to the personal computer  10  (Step  1002 ). 
     An object storage DB corresponding to a record whose DB updating flag  41 - 4  in the data base definition DB 41  is changed to “1” is searched and only the searched object storage DB is regarded as a DB to be synchronized. In the case of the data base definition DB 41  shown in FIG. 4, since the DB updating flags  41 - 4  of the records  412  and  415  have “1”, they are regarded as DBs to be synchronized. 
     Of the DBs considered to be synchronized (item definition DB 42 , object storage DB 45   a  (company)), only a record whose updating flag indicates “1” is transferred to the side of the personal computer  10 . 
     Merge at the personal computer  10  (Step  1003 ). DB on the side of the personal computer  10  is updated by the updated data which is transferred from the portable remote terminal  11 . 
     Transfer latest data to the portable remote terminal  11  (Step  1004 ). The personal computer  10  writes data updated later than the previous synchronization time over old data in the portable remote terminal  11 . 
     After the completion of the above-described transfer of the latest data, initialize a flag (Step  1005 ). The synchronization time and date  41 - 3  of the data base definition DB 41  is updated and the updating flags  41 - 4 ,  42 - 13  and  45 - 4  of the data base definition DB 41 , the item definition DB 42  and the object storage DB 45   a  (company) are initialized. 
     (4) Data Display Item Editing 
     A user selects and retains the order of data items to be displayed in data editing (display/input) on the portable remote terminal  11 . 
     Shown in FIG. 11 is a display screen  210  for making a user select the order of data items to be displayed in data editing (display/input) on the portable remote terminal  11  conducted by the application program B 31  illustrated in FIG.  3 . 
     DB data being read into the portable remote terminal  11  is displayed as record items within a window  221  at the left part of the screen. When there is one to be displayed among the items, selecting the item using the pen  13  as indicated by a highlight display example  242  leads to addition and deletion of display by arrow buttons  231   a  and  231   b . In the example of FIG. 11, pressing the arrow button  231   a  leads to addition of the item indicated by the highlighted display example  242  to a window  222  at the right part of the screen. A highlight display example ( 243 ) shows a state of an item being selected. 
     The order of displayed items can be changed by using arrow buttons  232   a  and  232   b  with respect to the highlight display example ( 243 ). Using the upward arrow  232   a  makes the highlight display example ( 243 ) have an immediately preceding displayed item and using the downward arrow  232   b  makes the highlight display example ( 243 ) have an immediately succeeding displayed item. 
     As described in the foregoing, the present embodiment enables the portable remote terminal  11  to arbitrarily take out a part of data items of the host DB 22  of the personal computer  10  and conduct data editing (display/modification/input). When a user brings out and uses the portable remote terminal  11  at his or her destination, therefore, effective use of data is possible. 
     As described in the foregoing, the system for linking data between a personal computer and a portable remote terminal of the present invention and the data linking method therefor attain the following effects. 
     First, the processing of taking in data from the personal computer into the portable remote terminal and the processing of synchronizing the portable remote terminal with the personal computer can be executed in a short time period because only the data that needs to be brought out from a data base of the computer by the portable remote terminal is selectable. 
     Secondly, quick application of data is enabled by selectively taking in data that needs to be brought out from a data base of the computer by the portable remote terminal. 
     Thirdly, since the order of displayed items or display/non-display of data brought out into the portable remote terminal can be changed by a user as required, efficient use of data is possible. 
     Although the invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodies within a scope encompassed and equivalents thereof with respect to the feature set out in the appended claims.