Saturday, February 25, 2012

Matching a Views columns to its underlying tables columns

Hello,

Using SQL Server 2000, I'm trying to put together a query that will
tell me the following information about a view:
The View Name
The names of the View's columns
The names of the source tables used in the view
The names of the columns that are used from the source tables

Borrowing code from the VIEW_COLUMN_USAGE view, I've got the code
below, which gives me the View Name, Source Table Name, and Source
Column Name. And I can easily enough get the View columns from the
syscolumns table. The problem is that I haven't figured out how to
link a source column name to a view column name. Any help would be
appreciated.

Gary

select
v_obj.name as ViewName,
t_obj.name as SourceTable,
t_col.name as SourceColumn
from
sysobjects t_obj,
sysobjects v_obj,
sysdepends dep,
syscolumns t_col
where
v_obj.xtype = 'V'
and dep.id = v_obj.id
and dep.depid = t_obj.id
and t_obj.id = t_col.id
and dep.depnumber = t_col.colid
order by
v_obj.name,
t_obj.name,
t_col.namegaryderousse@.yahoo.com (Gary DeRousse) wrote in message news:<9ce1cc62.0311051041.2dd0f428@.posting.google.com>...
> Hello,
> Using SQL Server 2000, I'm trying to put together a query that will
> tell me the following information about a view:
> The View Name
> The names of the View's columns
> The names of the source tables used in the view
> The names of the columns that are used from the source tables
> Borrowing code from the VIEW_COLUMN_USAGE view, I've got the code
> below, which gives me the View Name, Source Table Name, and Source
> Column Name. And I can easily enough get the View columns from the
> syscolumns table. The problem is that I haven't figured out how to
> link a source column name to a view column name. Any help would be
> appreciated.
> Gary
>
> select
> v_obj.name as ViewName,
> t_obj.name as SourceTable,
> t_col.name as SourceColumn
> from
> sysobjects t_obj,
> sysobjects v_obj,
> sysdepends dep,
> syscolumns t_col
> where
> v_obj.xtype = 'V'
> and dep.id = v_obj.id
> and dep.depid = t_obj.id
> and t_obj.id = t_col.id
> and dep.depnumber = t_col.colid
> order by
> v_obj.name,
> t_obj.name,
> t_col.name

I don't believe that this information is available - sysdepends
records that the dependency exists, but not exactly what the
dependency is. The mapping of view to table columns could be 1:N or
M:N (or 1:0, in fact), so I would guess that MS decided that it wasn't
worth the effort to try and capture the detailed column mapping.

Simon|||Simon,

Thanks for the information, even though it wasn't what I wanted to hear.

Gary

sql@.hayes.ch (Simon Hayes) wrote in message news:<60cd0137.0311060041.35542cec@.posting.google.com>...
> garyderousse@.yahoo.com (Gary DeRousse) wrote in message news:<9ce1cc62.0311051041.2dd0f428@.posting.google.com>...
> > Hello,
> > Using SQL Server 2000, I'm trying to put together a query that will
> > tell me the following information about a view:
> > The View Name
> > The names of the View's columns
> > The names of the source tables used in the view
> > The names of the columns that are used from the source tables
> > Borrowing code from the VIEW_COLUMN_USAGE view, I've got the code
> > below, which gives me the View Name, Source Table Name, and Source
> > Column Name. And I can easily enough get the View columns from the
> > syscolumns table. The problem is that I haven't figured out how to
> > link a source column name to a view column name. Any help would be
> > appreciated.
> > Gary
> > select
> > v_obj.name as ViewName,
> > t_obj.name as SourceTable,
> > t_col.name as SourceColumn
> > from
> > sysobjects t_obj,
> > sysobjects v_obj,
> > sysdepends dep,
> > syscolumns t_col
> > where
> > v_obj.xtype = 'V'
> > and dep.id = v_obj.id
> > and dep.depid = t_obj.id
> > and t_obj.id = t_col.id
> > and dep.depnumber = t_col.colid
> > order by
> > v_obj.name,
> > t_obj.name,
> > t_col.name
> I don't believe that this information is available - sysdepends
> records that the dependency exists, but not exactly what the
> dependency is. The mapping of view to table columns could be 1:N or
> M:N (or 1:0, in fact), so I would guess that MS decided that it wasn't
> worth the effort to try and capture the detailed column mapping.
> Simon

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