How to Add Multiple Instances of Table to Channel

Question

How to add multiple instances of a table to a channel?

Environment

HVR 5

Answer

In certain situations, e.g. when merging or splitting rows across tables, it is necessary to add multiple instances of the same base table to a channel.

The usual procedure using Table Select does not support adding a table multiple times. This would mean manually adding all columns as well, which is cumbersome especially when the table has lots of columns.

There are two methods to do this:

Method 1

1. Right-click on Tables and select New Table;
2. For Base Table Name enter the name of the table in the database (e.g. mytable), and for the Table Name enter the ‘alias’ for this table inside HVR.
3. Pick a different name for each instance (e.g. using a sequence number: mytable1, mytable2). Repeat this until you have the number of instances you require.
4. Go into the Table Select and connect to a location. The newly created tables are marked as Different Columns.
5. Select all of them and click Replace. HVR now replaces the empty column list with the list retrieved from the database ‘describe’ of the table.

Method 2

Alternatively, you can use the HVR XML import/export functionality to achieve this:

1. Add one instance of the table using Table Select in the usual way.
2. Export the HVR catalogs into an XML file either from the GUI (right-click on the channel) or using command hvrcatalogexport.
3. Open the XML file in a text editor and search for the definition of the table:

    <hvr_table chn_name="mychannel" tbl_name="mytable" tbl_base_name="mytable"/>
   

4. Copy this definition (changing the value for tbl_name) until you have the required number of instances:

    <hvr_table chn_name="mychannel" tbl_name="mytable2" tbl_base_name="mytable"/>
    <hvr_table chn_name="mychannel" tbl_name="mytable3" tbl_base_name="mytable"/>
   

5. Search for HVR's column definitions for this table:

    <hvr_column chn_name="mychannel" tbl_name="mytable" col_sequence="1" col_name="prod_id" col_key="1" col_datatype="integer4"/>
    <hvr_column chn_name="mychannel" tbl_name="mytable" col_sequence="2" col_name="prod_price" col_datatype="decimal" col_length="10,2"/>
   

6. Copy all column information for this table, each time replacing the tbl_name with the correct value until all of the added table instances have column information.
7. Import the resulting XML catalog file either from the HVR GUI (right-click on hub) or using the command hvrcatalogimport.