Because there are foreign key relationships between these tables, they need to be built in the order they are listed here - build parent tables first and child tables at the end. Categories table The difference to the Categories table in Access is that the Picture column is defined as VARCHAR2 in Oracle.
It only stores the image filename such as rather than a BLOB data type to store the actual image. In the caller applications, such as standalone applications or web based applications, we can define the image folder's path as a global variable, then the image path and the image filename can be joined to get the full path to the image.
An example of a more complex outer join condition in the WHERE clause is the case where the condition consists of a comparison between two table columns Note that the ( ) operator is used in two places: first in the equality comparison between the tables and second in the comparison condition for the EVENTID column.
The result of this syntax is the preservation of the outer-joined rows when the restriction on EVENTID is evaluated.
Customers table Customer_Code is a unique five-character code based on customers name.
Unlike the Access Northwind database where Customer_Code was used as the primary key, Customer_ID was created as the primary key in Oracle.
If you remove the ( ) operator from the EVENTID restriction, the query treats this restriction as a filter, not as part of the outer-join condition.
In turn, the outer-joined rows that contain nulls for EVENTID are eliminated from the result set.To produce the same behavior for all rows in TABLE2 that have no matching rows in TABLE1, specify The SALES table does not contain records for all listings in the LISTING table because not all listings result in sales.The following query outer-joins SALES and LISTING and returns rows from LISTING even when the SALES table reports no sales for a given list ID.PHONE IS 'Phone number includes country code or area code.'; COMMENT ON COLUMN CUSTOMERS.FAX IS 'Phone number includes country code or area code.'; 3.To get the full Oracle Northwind script and the image files, use the following links to download.