For fast performance, we should have an index on the key field that is used
in the related table.
The Related tab appears in the Info pane when a record in a table is picked with an Alt-click. It allows us to search for records in a secondary table that are related to the picked record, creating on-the-fly joins between the picked record and records in the other table. Up to ten related records from the other table are displayed.
For fast performance, we should have an index on the key field that is used
in the related table.
Specified relations persist for as long as the current project is open in the Manifold session. If we close the project or exit Manifold, the setup is not saved.
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Setup - Press to launch the Related dialog, to set up how related records are found and displayed. |
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Refresh - Repeat the search for related records using the criteria setup in the Related dialog. Useful to refill the related records list after switching out of and then returning to the Related tab. |
(table name) |
The name of the related table from which related records are shown will appear in the Related tab toolbar. |
(related list) |
A list of up to the first ten related records found, displaying fields as chosen in the Related dialog when the relation was set up. |
To show related records:
Alt-clicking a different record in the current table will automatically show related records in the Related tab. If we switch to different tabs and then back to the Related tab, or if we unpick the record in the current table and then pick a record again, we can get the related records list back by pressing the Refresh button.
To change the setup, for example, to find related records using a different table, press the Setup button and specify a different relation.
Specified relations persist for as long as the current project is open in the Manifold session. If we close the project or exit Manifold, the setup is not saved.
Use the Related dialog to specify relations to display in the Relations tab of the Info pane:
Current table |
The table we are currently using, in which we have Alt-clicked a record. |
Related table |
The secondary table in which we want to find records that are related to the record we have Alt-clicked in the current table. |
Key fields |
A field in the current table and a field in the related table that have the same value for related records.
Important: When working with larger related tables, the field used as key field in the related table should have an index on it. Take a moment to pop open the Schema dialog on the related table to verify that an index exists on the field that will be used as a key field. |
(Fields to display) |
A list of fields in the related table, allowing us to choose which fields will be displayed for related records in the Related tab. |
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Click a box to toggle between full (show the field) and empty (do not show the field. |
OK |
Apply the setup and search for records related to the Alt-clicked record using the specified related table and key fields. |
Cancel |
Close the dialog without changing any prior setup. |
We will use two tables that also feature in Join dialog examples, such as the Join Example: Add Publisher Name to a Table of Book Titles topic.
One table we will use is a table of book titles, seen above, where each title has a publisher code in the pub_id field.
The other table is a table of publishers, seen below, where each publisher also has a publisher code in the pub_id field.
With the focus on the publishers table, we Alt-click a record to pick that record. A triangle appears in the row handle to show the record has been picked.
Our intention is to see records in the titles table that are related to whatever record we pick in the publishers table. When we pick a publisher, we want to see a list of book titles from that publisher.
The Info pane immediately shows the picked record in the Values tab. We click the Related tab. The Related tab is empty, since we have not yet set up a relation to find related records.
We press the Setup
button to launch the Related dialog,
which allows us to set up a relation.
The Related dialog is very similar to the Join dialog. In the upper left is the current table, the publishers table. In the upper right is the related table, the table within which we want to find records that are related to the record we have Alt-clicked in the current table. The parameter boxes have pull down menus that are loaded with possible choices, for example, tables in our projects from which we can choose a related table, and fields within each table that we can use as a key field.
We choose the titles table as the related table. As soon as we choose the titles table, all of the fields in that table appear in the dialog as fields we can choose for display in the list of related records that the Related tab will show.
We choose the pub_id field in both the publishers table and in the titles table as the key fields to use. The Related dialog uses a simple understanding of related: two records are related when their key field values are the same.
We choose four fields from the titles table to show for related records that are listed. Press OK.
Immediately, the Related tab is populated with a list of records from the titles table that are related to the record we have Alt-clicked, which we can see by switching to the Values tab, as seen at right above. We can switch back and forth between the Values and Related tabs as we like. Each of the records shown in the Related tab is a book title record in the titles table that has publisher P01 in its pub_id field, the same publisher that we have Alt-clicked in the publishers table.
If we look at the titles table, we can see how the Related tab has searched for and has found titles for the publisher we picked in the publishers table. The Related tab displays the first ten related records it finds.
In the publishers table we can Alt-click a different publisher, to pick that publisher. We have picked the publisher with a pub_id code of P03.
Instantly, the Related tab updates to show related records from the titles table. In this case, there are only three titles from that publisher in the titles table.
As long as we pick different records in the publishers table, the Related tab in the Info pane will automatically refresh, to update the list of related records whenever we pick a different publisher. If we switch away from picked records, and then go back to picking records, we will have to refresh the list using the Refresh button.
With the focus on the publishers table, we can unpick the picked record by pressing Esc key.
With no picked record, the Info pane simply displays the default Component tab.
We now Alt-click a record in the publishers table. We have picked the publisher with code P02.
The Info pane immediately displays the values for that picked record in the Values tab. We click the Related tab to switch to the related records list.
The list is now empty, since we switched away from picking records. We recover the relation by pressing the Refresh button, and instantly the Related list is updated with records from the titles table that are related to the record we picked in the publishers table. In this case, the publisher has only one title.
Each table can have its own settings in the Relations tab. For example, in addition to the related records setting we have set up for the publishers table, we can also set up the Relations tab from the titles table.
The titles table lists a pub_id code for the publisher of each book title, but if we want to see the name of the publisher for a picked title, we can use the Related tab to do so.
We start by Alt-clicking a record in the titles table.
Picking a record pops open the Values tab in the Info pane, loaded with the fields for that record. We click on the Related tab to switch to that tab.
We press the Setup
button to launch the Related dialog.
In the Related dialog, we choose the publishers table as the related table, and we choose the pub_id field as the key field in both the current, titles table and in the related, publishers table.
We choose the country, pub_id, and pub_name fields to display for related records. Press OK.
The Related tab instantly shows the record related to the title we picked. Each title has only one publisher so there is only one related record in the publishers table for each title.
To see the name of the publisher for a different title, we Alt-click a different record to pick that title.
Right away, the Related tab reports the name of that publisher.
Panes are "live action" so if we switch back to the publishers table the relation we had set up for that table still works.
In the publishers table we Alt-click the second row to pick that publisher.
The Related tab instantly shows us related records, that is, all titles, from that publisher that are found in the titles table. In this case there is only one title published by that publisher, and thus only one related record to show.
Indexes - When using the Join dialog, we should have indexes in the original table and also the in the joined table for the fields in those tables that are used as key fields. The situation is simpler when using the Related tab in the Info pane: we only need an index on the key field that is used in the related table. The situation is simpler with the Relation tab because we have already picked a record in the current table with an Alt-click, so there is no need to search through a big table to find that record. We only need to search the related table, to find any records related to the record we have picked. To speed up that search, which works by finding key field values in the related table that match the key field for the field we have picked, we should have an index on the field we will use as a key field.
Assign Initial Coordinate System
Repair Initial Coordinate System
Example: Edit Coordinates While Creating an Object - When creating an object in a map using a tool such as Create Area, right in the middle of the process we can edit coordinates in the Info pane Coordinates tab. This example shows the step by step process.
Example: Edit Attributes and Move a Point - We look at the attributes for a point in a drawing layer and edit one of the attributes using a more expanded Edit dialog. We then move the point to a new location. Easy!
Example: Edit Attributes, Larger Text, IME for Asian Languages - A tour showing how to edit attributes in a drawing using the Info pane Values tab and the expanded Edit dialog, including advanced Unicode facilities and use of the built in Input Method Editor (IME) to input text in Japanese language.
Example: Assign Initial Coordinate System - Use the Info pane to manually assign an initial coordinate system when importing from a format that does not specify the coordinate system.
Example: Change Projection of an Image - Use the Reproject Component command to change the projection of an image, raster data showing terrain elevations in a region of Florida, from Latitude / Longitude to Orthographic centered on Florida.
Example: Create Parcels from Traverse Files - Traverse files using ESRI traverse file format are widely used by surveyors and government organizations in the US to define parcels and lines by describing a sequence of directions, distances and curves from a starting point. Manifold automatically handles both tangent and non-tangent curves in ESRI traverse file format as well as the full variety of options used to specify angles, distances and curves. This video shows how it's easy to create a parcel from a traverse file.
