Solution Guide for Migrating Oracle on UNIX to SQL Server - Willy .Net

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 111tables in a specific order based on the <strong>for</strong>eign key constraints (parent tables first). Optiontwo is to create tables in any order, leaving out the <strong>for</strong>eign key constraints, and addingthem after all the tables have been created.CommentsThis is a property of the table that is often not documented and, hence, easily overlookedduring a migration. SQL Server does not have a comment property associated with tablesand columns. However, SQL Server provides the capability to associate customproperties, called extended properties, with objects.Comments can be added to tables and columns using Enterprise Manager and systemstored procedures. To add a comment on tables and columns using Enterprise Manager, followthese steps:1. Expand Server, then Databases, and then the target database.2. Left-click Tables to display the list of tables.3. Right-click the target table and left-click Design Table. This brings up the TableDesigner.4. Comments <strong>for</strong> the individual columns can be added in the Description field of theColumns pane at the bottom of the Table Designer window.5. In the Table Designer window, click the Table and Index Properties button foundabove the grid.6. Left-click the Tables pane of the Properties window. Table comments can beadded in the Description field in the Tables pane.The sp_addextendedproperty system stored procedure can be used to add any userdefinedmetadata to any column in SQL Server. This (and any other properties that area dded to the column) can be retrieved with the fn_listextendedproperty function.Table 6.10 shows the syntax <strong>for</strong> adding comments at the table and column levels.Table 6.10: Comparison of Functionality<strong>for</strong> Adding Comments in <strong>Oracle</strong> andSQL Server<strong>Oracle</strong>COMMENT ON TABLE table_name IScommentCOMMENT ON COLUMNtable_name.column_name IS commentSQL Serversp_ addextendedproperty 'comment',comment,'user', schema_name, 'table',table_namesp_addextendedproperty 'comment',comment,'user', schema_name, 'table',table_name, 'column', column_nameConstraintsConstraints are data integrity rules that are defined on the columns of a table to en<strong>for</strong>cecertain business rules. As an example, the specification of data types in the definition ofthe column constitutes a constraint.