This post is part of a series on programming policy-based management. The series begins here.
So, we were working with a policy that required an ObjectSet. ObjectSets contain TargetSets. For example, the ObjectSet for the naming policy (IMultipartName) we were working on needs a TargetSet for Procedure, Synonym, Table, Function, Type, View, and XmlSchemaCollection.
Note that this collection is similar to what you'd see for a MultipartName policy in the SSMS designer dialog. The title for it in SSMS is "Against Targets:". We want our policy to apply only to Tables. After fumbling around for a while attempting to define TargetSets and add them to the ObjectSet's collection of them, I found that the seven TargetSets I needed were *already* defined. This reduces enabling only the table's TargetSet to two lines of additional code. Notice that you can reference a specific TargetSet in an ObjectSet by using an indexer. The indexer is an SMO URL.
TargetSet ts1 = os1.TargetSets["Server/Database/Table"];
ts1.Enabled = true;
But how to restrict this policy to a single database? For this we need a Condition to name the database. Because this condition is simple we can use ExpressionNode.Parse(). Here's the Condition code.
// Create a condition to enforce
Condition con = new Condition(ps, "FinanceDB");
con.Facet = "Database";
// Note: Using Parse() treats the string as an SMO URL. Only works for simplest cases
string s = "@Name = 'finance'";
// try-catch code omitted for brevity
con.ExpressionNode = ExpressionNode.Parse(s);
Back to our TargetSet. We restrict the TargetSet to a specific database by using TargetSet.SetLevelCondition. SetLevelCondition takes a TargetSetLevel, and we get the appropriate TargetSetLevel (which is prepopulated) by…. you guessed it…using a SMO URL. After ts1.Enabled, this limits the policy to a single database defined by our Condition.
// FinanceDB is the name of our Condition that "limit/defines" this policy only to Finance
Having initialized the ObjectSet correctly, we now create the ObjectSet, tie it to the Policy and voila…
p2.ObjectSet = "CheckFinanceTab_ObjectSet";
Check this policy by using the following code in a query window:
create table dbo.foo (id int);
You get the expected error:
Policy 'CheckFinanceTab' has been violated by '/Server/(local)/Database/finance/Table/dbo.foo'.
This transaction will be rolled back.
Policy description: ''
Additional help: '' : ''.
Msg 3609, Level 16, State 1, Procedure sp_syspolicy_dispatch_event, Line 50
The transaction ended in the trigger. The batch has been aborted.