The sub-lists are used to create and manage links, that are directed at the type table of the type relation displayed in the header form or originate from there. (Basically, links to all database tables can be created here, however, when the type relation in the header form is selected, only the links from or to the corresponding type table are displayed in the sub-list).
Link | name of the link between two tables |
Table-1 | name of the primary table |
Key-1 | name of the key field in the primary table |
Table-2 | name of the secondary table |
Key-2 | name of the key field in the secondary table |
>Ch (check value) | controls deleting data records in the primary table |
>Delete (delete flag) | controls actions in the secondary table when data records in the primary table are deleted |
>Outer Join | outer join flag |
<Ch (check value) | controls deleting data records in the secondary table |
<Del (delete flag) | controls actions in the primary table when data records in the secondary table are deleted |
>Outer Join | outer join flag |
Object Title | title of the object |
Comment | comment on the link record |
Form | displays the logical object for the secondary table in the form |
attribute | master attribute for link (T_CONSTRAINT) |
type, entry | string, entry required |
max. no. of characters | 20 |
selection tool | no |
multilingual field | no |
A link's name is the unique ID of the link object within the application's data model.
Table-1
You can enter (or select from the menu) only existing database tables.
Key-1
attribute
master attribute for link (T_CONSTRAINT)
type, entry
string, entry required
max. no. of characters
255
selection tool
menu with all fields of the table 1
multilingual field
no
The key is used to uniquely identify records in Table 1 of the link.
Names of Key fields may contain spaces, and several fields can be selected as Key fields. DataView then generates a string of comma-separated field names. <<CLEAR >> in the selection tool deletes the list of Key fields.
Only indexed fields should be used as keys.
Attention! Multilingual and system fields may not be used as keys in links.
More information:
-> Key fields for links
Table-2
You can enter (or select from the menu) only existing database tables.
Key-2
attribute
master attribute for link (T_CONSTRAINT)
type, entry
string, entry required
max. no. of characters
255
selection tool
menu with all fields of the table 2
multilingual field
no
The key is used to uniquely identify records in Table 2 of the link.
Names of Key fields may contain spaces, and several fields can be selected as Key fields. DataView then generates a string of comma-separated field names. <<CLEAR >> in the selection tool deletes the list of Key fields.
Only indexed fields should be used as keys.
Attention! Multilingual and system fields may not be used as keys in links.
More information:
-> Key fields for links
>Check Value
attribute
master attribute for link (T_CONSTRAINT)
type, entry
Integer, entry required
max. no. of characters
3
selection tool
no
multilingual field
no
The Check Value determines when the user can delete a record from Table 1 which is linked to records in Table 2. If the number of linked records in Table 2 is smaller than the Check Value, the record can be deleted from Table 1.
More information:
-> Checking for dependent elements
>Delete (flag)
attribute
master attribute for link (T_CONSTRAINT)
type, entry
string, entry required
max. no. of characters
1
selection tool
menu with possible actions
multilingual field
no
When master tables are linked to themselves (e.g. to display item or usage lists), entire structures could be deleted recursively. For safety's sake, DataView moves anything deleted recursively to the trash first.
More information:
-> Automatically deleting dependent elements
>Outer Join
attribute
master attribute for link (T_CONSTRAINT)
type, entry
logic
max. no. of characters
3
selection tool
no
multilingual field
no
More information:
-> Controlling display with outer joins
<Check Value
attribute
master attribute for link (T_CONSTRAINT)
type, entry
Integer, entry required
max. no. of characters
3
selection tool
no
multilingual field
no
The Check Value determines when the user can delete a record from Table 2 which is linked to records in Table 1. If the number of linked records in Table 1 is smaller than the Check Value, the record can be deleted from Table 2.
More information:
-> Checking for dependent elements
<Delete (flag)
attribute
master attribute for link (T_CONSTRAINT)
type, entry
string, entry required
max. no. of characters
1
selection tool
menu
multilingual field
no
When master tables are linked to themselves (e.g. to display item or usage lists), entire structures could be deleted recursively. For safety's sake, DataView moves anything deleted recursively to the trash first.
More information:
-> Automatically deleting dependent elements
<Outer Join
attribute
master attribute for link (T_CONSTRAINT)
type, entry
logic
max. no. of characters
3
selection tool
no
multilingual field
no
More information:
-> Controlling display with outer joins
Object Title
attribute
master attribute for link (T_CONSTRAINT)
type, entry
string, entry optional
max. no. of characters
20
selection tool
no
multilingual field
yes
The title is used in error messages.
Note!
You should always give your objects a title. If you don't, error messages will only contain the object's key, and you won't be able to find the object in a Search mask.
Comment
attribute
master attribute for link (T_CONSTRAINT)
type, entry
string, entry optional
max. no. of characters
255
selection tool
no
multilingual field
no
Form