org.apache.ddlutils.alteration

Class ModelComparator

java.lang.Object

org.apache.ddlutils.alteration.ModelComparator

Direct Known Subclasses:

MSSqlModelComparator, MySqlModelComparator

public class ModelComparator
extends Object

Compares two database models and creates change objects that express how to adapt the first model so that it becomes the second one. Neither of the models are changed in the process, however, it is also assumed that the models do not change in between.

Constructor Summary

Constructors

Constructor and Description
ModelComparator(PlatformInfo platformInfo, TableDefinitionChangesPredicate tableDefChangePredicate, boolean caseSensitive) Creates a new model comparator object.

Method Summary

Methods

Modifier and Type	Method and Description
protected List	checkForAddedColumns(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Creates change objects for columns that are not present in the given source table but are in the target table, and applies them to the given intermediate model.
protected List	checkForAddedForeignKeys(Database sourceModel, Database intermediateModel, Database targetModel) Creates change objects for foreign keys that are not present in the given source model but are in the target model, and applies them to the given intermediate model.
protected List	checkForAddedIndexes(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Creates change objects for indexes that are not present in the given source table but are in the target table, and applies them to the given intermediate model.
protected List	checkForAddedTables(Database sourceModel, Database intermediateModel, Database targetModel) Creates change objects for tables that are not present in the given source model but are in the target model, and applies them to the given intermediate model.
protected List	checkForChangedColumns(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Creates change objects for columns that have a different in the given source and target table, and applies them to the given intermediate model.
protected List	checkForChangeOfColumnOrder(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Checks for changes in the column order between the given source and target table, creates change objects for these and applies them to the given intermediate model.
protected List	checkForPrimaryKeyChanges(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Creates change objects for primary key differences (primary key added/removed/changed), and applies them to the given intermediate model.
protected List	checkForRemovedColumns(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Creates change objects for columns that are present in the given source table but are no longer in the target table, and applies them to the given intermediate model.
protected List	checkForRemovedForeignKeys(Database sourceModel, Database intermediateModel, Database targetModel) Creates change objects for foreign keys that are present in the given source model but are no longer in the target model, and applies them to the given intermediate model.
protected List	checkForRemovedIndexes(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Creates change objects for indexes that are present in the given source table but are no longer in the target table, and applies them to the given intermediate model.
protected List	checkForRemovedTables(Database sourceModel, Database intermediateModel, Database targetModel) Creates change objects for tables that are present in the given source model but are no longer in the target model, and applies them to the given intermediate model.
List	compare(Database sourceModel, Database targetModel) Compares the two models and returns the changes necessary to create the second model from the first one.
protected ColumnDefinitionChange	compareColumns(Table sourceTable, Column sourceColumn, Table targetTable, Column targetColumn) Compares the two columns and returns the change necessary to create the second column from the first one if they differe.
protected List	compareModels(Database sourceModel, Database intermediateModel, Database targetModel) Compares the given source and target models and creates change objects to get from the source to the target one.
protected List	compareTables(Database sourceModel, Table sourceTable, Database intermediateModel, Table intermediateTable, Database targetModel, Table targetTable) Compares the two tables and returns the changes necessary to create the second table from the first one.
protected ForeignKey	findCorrespondingForeignKey(Table table, ForeignKey fk) Searches in the given table for a corresponding foreign key.
protected Index	findCorrespondingIndex(Table table, Index index) Searches in the given table for a corresponding index.
protected String[]	getIntermediateColumnNamesFor(Column[] columns, Table intermediateTable) Returns the names of the columns in the intermediate table corresponding to the given column objects.
protected PlatformInfo	getPlatformInfo() Returns the info object for the platform.
protected boolean	isCaseSensitive() Determines whether comparison should be case sensitive.
void	setCanDropPrimaryKeyColumns(boolean canDropPrimaryKeyColumns) Specifies whether the RemoveColumnChange are fine even for primary key columns.
void	setGeneratePrimaryKeyChanges(boolean generatePrimaryKeyChanges) Specifies whether the comparator should generate PrimaryKeyChange objects or a pair of RemovePrimaryKeyChange and AddPrimaryKeyChange objects instead.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ModelComparator

public ModelComparator(PlatformInfo platformInfo,
               TableDefinitionChangesPredicate tableDefChangePredicate,
               boolean caseSensitive)

Creates a new model comparator object.

Parameters:

platformInfo - The platform info

tableDefChangePredicate - The predicate that defines whether tables changes are supported by the platform or not; all changes are supported if this is null

caseSensitive - Whether comparison is case sensitive

Method Detail

setGeneratePrimaryKeyChanges

public void setGeneratePrimaryKeyChanges(boolean generatePrimaryKeyChanges)

Specifies whether the comparator should generate PrimaryKeyChange objects or a pair of RemovePrimaryKeyChange and AddPrimaryKeyChange objects instead. The default value is true.

Parameters:

generatePrimaryKeyChanges - Whether to create PrimaryKeyChange objects

setCanDropPrimaryKeyColumns

public void setCanDropPrimaryKeyColumns(boolean canDropPrimaryKeyColumns)

Specifies whether the RemoveColumnChange are fine even for primary key columns. If the platform cannot drop primary key columns, set this to false and the comparator will create additional primary key changes. The default value is true.

Parameters:

canDropPrimaryKeyColumns - Whether RemoveColumnChange objecs for primary key columns are ok

getPlatformInfo

protected PlatformInfo getPlatformInfo()

Returns the info object for the platform.

Returns:

The platform info object

isCaseSensitive

protected boolean isCaseSensitive()

Determines whether comparison should be case sensitive.

Returns:

true if case matters

compare

public List compare(Database sourceModel,
           Database targetModel)

Compares the two models and returns the changes necessary to create the second model from the first one.

Parameters:

sourceModel - The source model

targetModel - The target model

Returns:

The changes

compareModels

protected List compareModels(Database sourceModel,
                 Database intermediateModel,
                 Database targetModel)

Compares the given source and target models and creates change objects to get from the source to the target one. These changes will be applied to the given intermediate model (the other two won't be changed), so that it will be equal to the target model after this model has finished.

Parameters:

sourceModel - The source model

intermediateModel - The intermediate model to apply the changes to

targetModel - The target model

Returns:

The changes

checkForRemovedForeignKeys

protected List checkForRemovedForeignKeys(Database sourceModel,
                              Database intermediateModel,
                              Database targetModel)

Creates change objects for foreign keys that are present in the given source model but are no longer in the target model, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

intermediateModel - The intermediate model to apply the changes to

targetModel - The target model

Returns:

The changes

checkForAddedForeignKeys

protected List checkForAddedForeignKeys(Database sourceModel,
                            Database intermediateModel,
                            Database targetModel)

Creates change objects for foreign keys that are not present in the given source model but are in the target model, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

intermediateModel - The intermediate model to apply the changes to

targetModel - The target model

Returns:

The changes

checkForRemovedTables

protected List checkForRemovedTables(Database sourceModel,
                         Database intermediateModel,
                         Database targetModel)

Creates change objects for tables that are present in the given source model but are no longer in the target model, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

intermediateModel - The intermediate model to apply the changes to

targetModel - The target model

Returns:

The changes

checkForAddedTables

protected List checkForAddedTables(Database sourceModel,
                       Database intermediateModel,
                       Database targetModel)

Creates change objects for tables that are not present in the given source model but are in the target model, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

intermediateModel - The intermediate model to apply the changes to

targetModel - The target model

Returns:

The changes

compareTables

protected List compareTables(Database sourceModel,
                 Table sourceTable,
                 Database intermediateModel,
                 Table intermediateTable,
                 Database targetModel,
                 Table targetTable)

Compares the two tables and returns the changes necessary to create the second table from the first one.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to which the changes will be applied incrementally

intermediateTable - The table corresponding to the source table in the intermediate model

targetModel - The target model which contains the target table

targetTable - The target table

Returns:

The changes

getIntermediateColumnNamesFor

protected String[] getIntermediateColumnNamesFor(Column[] columns,
                                     Table intermediateTable)

Returns the names of the columns in the intermediate table corresponding to the given column objects.

Parameters:

columns - The column objects

intermediateTable - The intermediate table

Returns:

The column names

checkForRemovedIndexes

protected List checkForRemovedIndexes(Database sourceModel,
                          Table sourceTable,
                          Database intermediateModel,
                          Table intermediateTable,
                          Database targetModel,
                          Table targetTable)

Creates change objects for indexes that are present in the given source table but are no longer in the target table, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to apply the changes to

intermediateTable - The table from the intermediate model corresponding to the source table

targetModel - The target model

targetTable - The target table

Returns:

The changes

checkForAddedIndexes

protected List checkForAddedIndexes(Database sourceModel,
                        Table sourceTable,
                        Database intermediateModel,
                        Table intermediateTable,
                        Database targetModel,
                        Table targetTable)

Creates change objects for indexes that are not present in the given source table but are in the target table, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to apply the changes to

intermediateTable - The table from the intermediate model corresponding to the source table

targetModel - The target model

targetTable - The target table

Returns:

The changes

checkForChangeOfColumnOrder

protected List checkForChangeOfColumnOrder(Database sourceModel,
                               Table sourceTable,
                               Database intermediateModel,
                               Table intermediateTable,
                               Database targetModel,
                               Table targetTable)

Checks for changes in the column order between the given source and target table, creates change objects for these and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to apply the changes to

intermediateTable - The table from the intermediate model corresponding to the source table

targetModel - The target model

targetTable - The target table

Returns:

The changes

checkForRemovedColumns

protected List checkForRemovedColumns(Database sourceModel,
                          Table sourceTable,
                          Database intermediateModel,
                          Table intermediateTable,
                          Database targetModel,
                          Table targetTable)

Creates change objects for columns that are present in the given source table but are no longer in the target table, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to apply the changes to

intermediateTable - The table from the intermediate model corresponding to the source table

targetModel - The target model

targetTable - The target table

Returns:

The changes

checkForAddedColumns

protected List checkForAddedColumns(Database sourceModel,
                        Table sourceTable,
                        Database intermediateModel,
                        Table intermediateTable,
                        Database targetModel,
                        Table targetTable)

Creates change objects for columns that are not present in the given source table but are in the target table, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to apply the changes to

intermediateTable - The table from the intermediate model corresponding to the source table

targetModel - The target model

targetTable - The target table

Returns:

The changes

checkForChangedColumns

protected List checkForChangedColumns(Database sourceModel,
                          Table sourceTable,
                          Database intermediateModel,
                          Table intermediateTable,
                          Database targetModel,
                          Table targetTable)

Creates change objects for columns that have a different in the given source and target table, and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to apply the changes to

intermediateTable - The table from the intermediate model corresponding to the source table

targetModel - The target model

targetTable - The target table

Returns:

The changes

checkForPrimaryKeyChanges

protected List checkForPrimaryKeyChanges(Database sourceModel,
                             Table sourceTable,
                             Database intermediateModel,
                             Table intermediateTable,
                             Database targetModel,
                             Table targetTable)

Creates change objects for primary key differences (primary key added/removed/changed), and applies them to the given intermediate model.

Parameters:

sourceModel - The source model

sourceTable - The source table

intermediateModel - The intermediate model to apply the changes to

intermediateTable - The table from the intermediate model corresponding to the source table

targetModel - The target model

targetTable - The target table

Returns:

The changes

compareColumns

protected ColumnDefinitionChange compareColumns(Table sourceTable,
                                    Column sourceColumn,
                                    Table targetTable,
                                    Column targetColumn)

Compares the two columns and returns the change necessary to create the second column from the first one if they differe.

Parameters:

sourceTable - The source table which contains the source column

sourceColumn - The source column

targetTable - The target table which contains the target column

targetColumn - The target column

Returns:

The change or null if the columns are the same

findCorrespondingForeignKey

protected ForeignKey findCorrespondingForeignKey(Table table,
                                     ForeignKey fk)

Searches in the given table for a corresponding foreign key. If the given key has no name, then a foreign key to the same table with the same columns (but not necessarily in the same order) is searched. If the given key has a name, then the corresponding key also needs to have the same name, or no name at all, but not a different one.

Parameters:

table - The table to search in

fk - The original foreign key

Returns:

The corresponding foreign key if found

findCorrespondingIndex

protected Index findCorrespondingIndex(Table table,
                           Index index)

Searches in the given table for a corresponding index. If the given index has no name, then a index to the same table with the same columns in the same order is searched. If the given index has a name, then the a corresponding index also needs to have the same name, or no name at all, but not a different one.

Parameters:

table - The table to search in

index - The original index

Returns:

The corresponding index if found