How to define default where clause on a table in oracle?

by darrion.kuhn , in category: MySQL , 5 months ago

How to define default where clause on a table in oracle?

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1 answer

by raven_corwin , 5 months ago

@darrion.kuhn 

To define a default WHERE clause on a table in Oracle, you can use a view or a global filter.

  1. Using a View: You can create a view that includes the default WHERE clause conditions. For example, if you want to filter out all rows with a specific value in a column named 'status', you can create a view like this:
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CREATE OR REPLACE VIEW my_table_view AS
SELECT *
FROM my_table
WHERE status <> 'inactive';


Now, when you query the view 'my_table_view', it will only return rows where the 'status' column is not equal to 'inactive'.

  1. Using a Global Filter: You can also define a global filter on the table itself. This can be done by setting the ROW LEVEL SECURITY attribute of the table to 'ENABLE'. Then, you can define a policy function that includes the default WHERE clause conditions. For example:
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CREATE OR REPLACE FUNCTION my_table_filter (schema VARCHAR, table_name VARCHAR)
RETURN VARCHAR
AS
BEGIN
  RETURN 'status <> ''inactive''';
END;
/

BEGIN
  DBMS_RLS.ADD_POLICY (
    object_schema => 'your_schema',
    object_name => 'my_table',
    policy_name => 'my_table_policy',
    function_schema => 'your_schema',
    policy_function => 'my_table_filter',
    statement_types => 'SELECT'
  );
END;
/


With this global filter in place, any query on the 'my_table' table will automatically apply the default WHERE clause condition defined in the 'my_table_filter' function.


By using either of these methods, you can define a default WHERE clause on a table in Oracle to filter the data based on specific conditions.