I'm using this approach to create a trigger to catch data changes. However, the system allows schema changes, and I would like to create this trigger dynamically after a new table has been created. I was trying to separate the logic into a stored procedure and call it in the trigger body, but in the stored procedure context, there's no access to inserted / updated. Is there any better approach to achieve the same result?
CREATE PROC X
@TableNameValue varchar(50)
AS
declare @bit int ,
@field int ,
@maxfield int ,
@char int ,
@fieldname varchar(128) ,
@TableName varchar(128) ,
@PKCols varchar(1000) ,
@sql varchar(2000),
@UpdateDate varchar(21) ,
@UserName varchar(128) ,
@Type char(1) ,
@PKFieldSelect varchar(1000),
@PKValueSelect varchar(1000)
select @TableName = @TableNameValue
-- date and user
select @UserName = system_user ,
@UpdateDate = convert(varchar(8), getdate(), 112) + ' ' + convert(varchar(12), getdate(), 114)
-- Action
if exists (select * from inserted)
if exists (select * from deleted)
select @Type = 'U'
else
select @Type = 'I'
else
select @Type = 'D'
-- get list of columns
select * into #ins from inserted
select * into #del from deleted
-- Get primary key columns for full outer join
select @PKCols = coalesce(@PKCols + ' and', ' on') + ' i.' + c.COLUMN_NAME + ' = d.' + c.COLUMN_NAME
from INFORMATION_SCHEMA.TABLE_CONSTRAINTS pk ,
INFORMATION_SCHEMA.KEY_COLUMN_USAGE c
where pk.TABLE_NAME = @TableName
and CONSTRAINT_TYPE = 'PRIMARY KEY'
and c.TABLE_NAME = pk.TABLE_NAME
and c.CONSTRAINT_NAME = pk.CONSTRAINT_NAME
-- Get primary key fields select for insert
select @PKFieldSelect = coalesce(@PKFieldSelect+'+','') + '''' + COLUMN_NAME + ''''
from INFORMATION_SCHEMA.TABLE_CONSTRAINTS pk ,
INFORMATION_SCHEMA.KEY_COLUMN_USAGE c
where pk.TABLE_NAME = @TableName
and CONSTRAINT_TYPE = 'PRIMARY KEY'
and c.TABLE_NAME = pk.TABLE_NAME
and c.CONSTRAINT_NAME = pk.CONSTRAINT_NAME
select @PKValueSelect = coalesce(@PKValueSelect+'+','') + 'convert(varchar(100), coalesce(i.' + COLUMN_NAME + ',d.' + COLUMN_NAME + '))'
from INFORMATION_SCHEMA.TABLE_CONSTRAINTS pk ,
INFORMATION_SCHEMA.KEY_COLUMN_USAGE c
where pk.TABLE_NAME = @TableName
and CONSTRAINT_TYPE = 'PRIMARY KEY'
and c.TABLE_NAME = pk.TABLE_NAME
and c.CONSTRAINT_NAME = pk.CONSTRAINT_NAME
if @PKCols is null
begin
raiserror('no PK on table %s', 16, -1, @TableName)
return
end
AND FOR EVERY SCHEMA CHANGE I WOULD RUN THIS STATEMENT
PS: trigtest is the new table, I've hardcoded just to test it
create trigger trigtest_ChangeTracking on trigtest for insert, update, delete
as
declare @TableNameValue varchar(50)
set @TableNameValue = 'trigtest'
exec X @TableNameValue