The modColumns table extends the SQL Server schema information for solution table columns. For a SQL Server store, it is an extension of the sysColumns table.
The modColumns table stores entries for selected columns in a team solution that require additional properties. For each column, it stores a local ID required to link the column with its parent column in a hierarchy, the table ID, and the column name. The name and the table ID make up the primary key and relate modColumns and sysColumns in a one-to-one relationship.
Caution You do not alter the modColumns table manually. Use the Access Workflow Designer and the Team Solutions Manager to make changes. Schema integrity is not guaranteed if you make manual changes to any solutions system tables.
The modColumns table contains four general types of columns. The following table provides a brief description of each.
| Column type | Description |
| State columns | Each workflow-enabled table has an associated state column, which controls the workflow. State columns have an associated workflow table and lookup table, which are stored in modColumns. |
| Lookup columns | For each such column, the lookup table ID is stored in modColumns. |
| Hierarchy columns | A parent-child hierarchy is defined by a relationship between a parent column and a child column. For all child user tables, the related column has an entry in modColumns and stores the ID of the related column in the parent table. |
| Other columns | If a solution must define attributes, such as Caption or Searchable, or add any other custom property to a column, it should add the column to modColumns. |
The modColumns database table contains a number of columns used by the team solutions. The following table lists those columns and their data types and provides a brief description of each.
| Column | Data type | Description |
| Id | identity (int) | Unique identifier for the column used only by the modColumns table. |
| Table_id | int | Unique identifier for the column table in modObjects. |
| Name | nvarchar(128) | Column name. |
| Workflow_id | int | ID of the workflow table or Null. |
| Lookup_id | int | ID of the lookup table or Null. |
| Parent_col_id | int | ID of the related column in the parent table. |
| Caption | nvarchar(256) | Friendly name of the object component used as the caption for tables or columns (for example, "Issue due date"). |
| Properties | ntext | Reserved for user-defined properties. |
| rowguid | uniqueidentifier | Unique identifier used for replication. |