When data that includes circular references is loaded into QlikView, loosely coupled tables are created automatically, to avoid that the circular references create a loop in the QlikView internal logic. These loosely coupled tables need to be handled in order to visualize data in a way that is expected and understandable.
Understanding circular references
Any table can also be made loosely coupled interactively from this dialog or via macros.
The normal QlikView associative logic is disconnected internally for loosely coupled tables. This means that selections in one field do not propagate through to the other fields in the table. This may be very useful in a number of situations, typically when it is needed to avoid circular references in the data structure.
This dialog page consists of two lists, the Tables list and the Fields list.
Either table can be sorted on any column, by clicking its column header.
The Tables list contains the following information:
| Property | Description |
|---|---|
| Name | The name of the internal table. |
| Loosely Coupled | If the alternative is checked, the table is loosely coupled. It is possible to deliberately set this alternative for a table here. |
| # Records | The number of records (rows) of the table. |
| # Fields | The number of fields (columns) of the table. |
| # Keys | The number of key (connecting) fields (columns) of the table. |
| Comment |
Displays the comments read from the data source and the comment made on the field. |
The Fields list at the bottom of the page shows all fields of the QlikView document or, if one internal table has been selected in the list above, the fields of that table. The columns are as follows:
| Property | Description |
|---|---|
| # | The internal number of the field. Numbers 0 to 5 are used by the QlikView system fields, which are not displayed in this list. |
| Name | The name of the field. |
| Dimensions | Mark the check box to the right of the field name to add the system tag $dimension to the field. This tag denotes a field recommended for use in chart dimensions, list boxes etc. A field tagged with dimension will be displayed at the top of all field selection controls in QlikView except in the Edit Expression dialog. |
| Measures | Mark the check box to the right of the field name to add the system tag $measure to the field.. This tag denotes a field recommended for use in expressions. A field tagged with measure will be displayed at the top of all field selection controls in the Edit Expression dialog. |
| Tags |
Displays the field tags. $ denotes a system tag. |
| Comment | Displays the comments read from the data source and an indicator for any special status of the field, such as Semantic, AndMode, AlwaysOneSelected, Info, Locked or Hidden. |
| # Tables | The number of tables in which the field occurs. |
| # Values | The total number of field values, disregarding selections. This information is not available for key (connecting) fields. |
| # Distinct | The total number of distinct field values, disregarding selections. |
| Type |
Displays an indicator for any special status of the field, such as Semantic, AndMode, AlwaysOneSelected, Locked or Hidden. |
| Edit Tags... | Opens a dialog where it is possible to add and remove tags. System tags cannot be removed here. Tags added may not be given a name occupied by a system tag. |
| Export Structure | By pressing this button it is possible to export the table structure of the document to a set of text files. These text files, one for the tables (file-name.Tables.tab), one for the fields (filename.Fields.tab) and one for mapping in between (filename.Mappings.tab) can easily be read back into QlikView for further analysis with the full power of the QlikView logic. A dialog will appear where the target folder can be chosen for the export. The default is to put the files in the same folder as the QlikView document. |
| Tag Clean-Up | Click this button to clean up any tags that might be left after a field has been removed from the QlikView document. |
