List of Refactorings and Transformations

Add CRUD Methods (page 232): Introduce stored procedures (methods) to implement the creation, retrieval, update, and deletion (CRUD) of the data representing a business entity.

Add Foreign Key Constraint (page 204): Add a foreign key constraint to an existing table to enforce a relationship to another table.

Add Lookup Table (page 153): Create a lookup table for an existing column.

Add Mirror Table (page 236): Create a mirror table, an exact duplicate of an existing table in one database, in another database.

Add Parameter (page 278): Existing method needs information that was not passed in before.

Add Read Method (page 240): Introduce a method—in this case, a stored procedure—to implement the retrieval of the data representing zero or more business entities from the database.

Add Trigger For Calculated Column (page 209): Introduce a new trigger to update the value contained in a calculated column.

Apply Standard Codes (page 157): Apply a standard set of code values to a single column to ensure that it conforms to the values of similar columns stored elsewhere in the database.

Apply Standard Type (page 162): Ensure that the data type of a column is consistent with the data type of other similar columns within the database.

Consolidate Conditional Expression (page 283): Combine sequence of conditional tests into a single conditional expression and extract it.

Consolidate Key Strategy (page 168): Choose a single key strategy for an entity and apply it consistently throughout your database.

Decompose Conditional (page 284): Extract methods from the condition.

Drop Column (page 72): Remove a column from an existing table.

Drop Column Constraint (page 172): Remove a column constraint from an existing table.

Drop Default Value (page 174): Remove the default value that is provided by a database from an existing table column.

Drop Foreign Key Constraint (page 213): Remove a foreign key constraint from an existing table so that a relationship to another table is no longer enforced by the database.

Drop Non-Nullable (page 177): Change an existing non-nullable column so that it accepts null values.

Drop Table (page 77): Remove an existing table from the database.

Drop View (page 79): Remove an existing view.

Encapsulate Table With View (page 243): Wrap access to an existing table with a view.

Extract Method (page 285): Turn the code fragment into a method whose name explains the purpose of the method.

Insert Data (page 296): Insert data into an existing table.

Introduce Calculated Column (page 81): Introduce a new column based on calculations involving data in one or more tables.

Introduce Calculation Method (page 245): Introduce a new method, typically a stored function, which implements a calculation that uses data stored within the database.

Introduce Cascading Delete (page 215): Ensure that the database automatically deletes the appropriate “child records” when a “parent record” is deleted.

Introduce Column Constraint (page 180): Introduce a column constraint in an existing table.

Introduce Common Format (page 183): Apply a consistent format to all the data values in an existing table column.

Introduce Default Value (page 186): Let the database provide a default value for an existing table column.

Introduce Hard Delete (page 219): Remove an existing column which indicates that a row has been deleted and instead actually delete the row.

Introduce Index (page 248): Introduce a new index of either unique or non-unique type.

Introduce New Column (page 301): Introduce a new column in an existing table.

Introduce New Table (page 304): Introduce a new table in an existing database.

Introduce Read-Only Table (page 251): Create a read-only data store based on existing tables in the database.

Introduce Soft Delete (page 222): Introduce a flag to an existing table which indicates that a row has been deleted instead of actually deleting the row.

Introduce Surrogate Key (page 85): Replace an existing natural key with a surrogate key.

Introduce Trigger For History (page 227): Introduce a new trigger to capture data changes for historical or audit purposes.

Introduce Variable (page 287): Put the result of the expression, or parts of the expression, in a temporary variable with a name that explains the purpose.

Introduce View (page 306): Create a view based on existing tables in the database.

Make Column Non-Nullable (page 189): Change an existing column so that it does not accept any null values.

Merge Columns (page 92): Merge two or more columns within a single table.

Merge Tables (page 96): Merge two or more tables into a single table.

Migrate Method From Database (page 257): Rehost an existing database method (a stored procedure, stored function, or trigger) in the application(s) which currently invoke it.

Migrate Method To Database (page 261): Rehost existing application logic in the database.

Move Column (page 103): Migrate a table column, with all of its data, to another existing table.

Move Data (page 192): Move the data contained within a table, either all or a subset of its columns, to another existing table.

Parameterize Method (page 278): Create one method that uses a parameter for the different values.

Remove Control Flag (page 289): Use return or break instead of a variable acting as a control flag.

Remove Middle Man (page 289): Get the caller to call the method directly.

Remove Parameter (page 279): Remove a parameter no longer used by the method body.

Rename Column (page 109): Rename an existing table column with a name that explains its purpose.

Rename Method (page 279): Rename an existing method with a name that explains its purpose.

Rename Table (page 113): Rename an existing table with a name that explains its purpose.

Rename View (page 117): Rename an existing view with a name that explains its purpose.

Reorder Parameters (page 281): Change the order of the parameters of a method.

Replace Column (page 126): Replace an existing non-key column with a new one.

Replace LOB With Table (page 120): Replace a large object (LOB) column that contains structured data with a new table or in the same table.

Replace Literal With Table Lookup (page 290): Replace code constants with values from database tables.

Replace Method(s) With View (page 265): Create a view based on one or more existing database methods (stored procedures, stored functions, or triggers) within the database.

Replace Nested Conditional With Guard Clauses (page 292): Remove nested if conditions with a series of separate IF statements.

Replace One-To-Many With Associative Table (page 130): Replace a one-to-many association between two tables with an associative table.

Replace Parameter With Explicit Methods (page 282): Create a separate method for each value of the parameter.

Replace Surrogate Key With Natural Key (page 135): Replace a surrogate key with an existing natural key.

Replace Type Code With Property Flags (page 196): Replace a code column with individual property flags, usually implemented as Boolean columns, within the same table column.

Replace View With Method(s) (page 268): Replace an existing view with one or more existing methods (stored procedures, stored functions, or triggers) within the database.

Split Column (page 140): Split a column into one or more columns within a single table.

Split Table (page 145): Vertically split (e.g., by columns) an existing table into one or more tables.

Split Temporary Variable (page 292): Make a separate temporary variable for each assignment.

Substitute Algorithm (page 293): Replace the body of the method with the new algorithm.

Update Data (page 310): Update data within an existing table.

Use Official Data Source (page 271): Use the official data source for a given entity, instead of the current one you are using.