Package net.java.ao.db

Class H2DatabaseProvider

java.lang.Object
net.java.ao.DatabaseProvider
net.java.ao.db.H2DatabaseProvider
All Implemented Interfaces:
Disposable
public class H2DatabaseProvider extends DatabaseProvider

  • Constructor Details

  • Method Details

    • renderQueryLimit

      protected String renderQueryLimit(Query query)
      Description copied from class: DatabaseProvider

      Renders the LIMIT portion of the query in the database-specific SQL dialect. There is wide variety in database implementations of this particular SQL clause. In fact, many database do not support it at all.

      Unfortunately, we live in the real world of proprietary database implementations that requires us to use database specific keywords or semantics to achieve these outcomes. Appropriate methods should be overridden in such cases.

      An example return value: " LIMIT 10,2"

      There is usually no need to call this method directly. Under normal operations it functions as a delegate for DatabaseProvider.renderQuery(Query, TableNameConverter, boolean).

      Overrides:
      renderQueryLimit in class DatabaseProvider
      Parameters:
      query - The Query instance from which to determine the LIMIT properties.
      Returns:
      The database-specific SQL rendering of the LIMIT portion of the query.

    • renderAlterTableAddColumn

      protected Iterable<SQLAction> renderAlterTableAddColumn(NameConverters nameConverters, DDLTable table, DDLField field)
      Description copied from class: DatabaseProvider
      Generates the database-specific DDL statements required to add a column to an existing table. Included in the return value should be the statements required to add all necessary functions and triggers to ensure that the column acts appropriately. For example, if the field is tagged with an @OnUpdate annotation, chances are there will be a trigger and possibly a function along with the ALTER statement. These "extra" functions are properly ordered and will only be appended if their values are not null. Because of this, very few database providers will need to override this method.

      Each SQLAction should have a corresponding undo action; these will be executed in reverse order if the action needs to be rolled back.

      Overrides:
      renderAlterTableAddColumn in class DatabaseProvider
      table - The table which should receive the new column.
      field - The column to add to the specified table.
      Returns:
      An array of DDL statements to execute.
      See Also:
      • #renderFunctionForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)
      • #renderTriggerForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.SequenceNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)

    • renderAlterTableChangeColumn

      protected Iterable<SQLAction> renderAlterTableChangeColumn(NameConverters nameConverters, DDLTable table, DDLField oldField, DDLField field)
      Description copied from class: DatabaseProvider

      Generates the database-specific DDL statements required to change the given column from its old specification to the given DDL value. This method will also generate the appropriate statements to remove old triggers and functions, as well as add new ones according to the requirements of the new field definition.

      The default implementation of this method functions in the manner specified by the MySQL database. Some databases will have to perform more complicated actions (such as dropping and re-adding the field) in order to satesfy the same use-case. Such databases should print a warning to stderr to ensure that the end-developer is aware of such restrictions.

      Thus, the specification for this method allows for data loss. Nevertheless, if the database supplies a mechanism to accomplish the task without data loss, it should be applied.

      For maximum flexibility, the default implementation of this method only deals with the dropping and addition of functions and triggers. The actual generation of the ALTER TABLE statement is done in the DatabaseProvider.renderAlterTableChangeColumnStatement(net.java.ao.schema.NameConverters, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField, net.java.ao.schema.ddl.DDLField, net.java.ao.DatabaseProvider.RenderFieldOptions) method.

      Overrides:
      renderAlterTableChangeColumn in class DatabaseProvider
      table - The table containing the column to change.
      oldField - The old column definition.
      field - The new column definition (defining the resultant DDL). @return An array of DDL statements to be executed.
      See Also:
      • #getTriggerNameForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)
      • #getFunctionNameForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)
      • #renderFunctionForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)
      • #renderTriggerForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.SequenceNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)

    • renderAlterTableChangeColumnStatement

      protected SQLAction renderAlterTableChangeColumnStatement(NameConverters nameConverters, DDLTable table, DDLField oldField, DDLField field, DatabaseProvider.RenderFieldOptions options)
      Description copied from class: DatabaseProvider
      Generates the database-specific DDL statement only for altering a table and changing a column. This method must only generate a single statement as it does not need to concern itself with functions or triggers associated with the column. This method is only to be called as a delegate for the DatabaseProvider.renderAlterTableChangeColumn(net.java.ao.schema.NameConverters, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField, net.java.ao.schema.ddl.DDLField) method, for which it is a primary delegate. The default implementation of this method functions according to the MySQL specification.
      Overrides:
      renderAlterTableChangeColumnStatement in class DatabaseProvider
      table - The table containing the column to change.
      oldField - The old column definition.
      field - The new column definition (defining the resultant DDL).
      Returns:
      A single DDL statement which is to be executed.
      See Also:

    • renderFieldForLatestH2

      protected String renderFieldForLatestH2(DDLTable table, DDLField field)

    • renderConstraints

      protected String renderConstraints(NameConverters nameConverters, List<String> primaryKeys, DDLTable table)
      Overrides:
      renderConstraints in class DatabaseProvider

    • renderFieldDefault

      protected String renderFieldDefault(DDLTable table, DDLField field)
      Overrides:
      renderFieldDefault in class DatabaseProvider

    • renderAlterTableDropKey

      protected SQLAction renderAlterTableDropKey(DDLForeignKey key)
      Description copied from class: DatabaseProvider
      Generates the database-specific DDL statement required to remove a foreign key from a table. For databases which do not support such a statement, a warning should be printed to stderr and a null value returned. This method assumes that the DatabaseProvider.renderForeignKey(DDLForeignKey) method properly names the foreign key according to the DDLForeignKey.getFKName() method.
      Overrides:
      renderAlterTableDropKey in class DatabaseProvider
      Parameters:
      key - The foreign key to be removed. As this instance contains all necessary data (such as domestic table, field, etc), no additional parameters are required.
      Returns:
      A DDL statement to be executed, or null.

    • renderDropIndex

      protected SQLAction renderDropIndex(IndexNameConverter indexNameConverter, DDLIndex index)
      Description copied from class: DatabaseProvider
      Generates the database-specific DDL statement required to drop an index. The syntax for this operation is highly standardized and thus it is unlikely this method will be overridden. If the database in question does not support indexes, a warning should be printed to stderr and null returned.
      Overrides:
      renderDropIndex in class DatabaseProvider
      index - The index to drop. This single instance contains all of the data necessary to drop the index, thus no separate parameters (such as a DDLTable) are required.
      Returns:
      A DDL statement to be executed, or null.

    • renderConstraintsForTable

      protected String renderConstraintsForTable(UniqueNameConverter uniqueNameConverter, DDLTable table)
      Description copied from class: DatabaseProvider
      Renders the foreign key constraints in database-specific DDL for the table in question. Actually, this method only loops through the foreign keys and renders indentation and line-breaks. The actual rendering is done in a second delegate method.
      Overrides:
      renderConstraintsForTable in class DatabaseProvider
      table - The database-agnostic DDL representation of the table in question.
      Returns:
      The String rendering of all of the foreign keys for the table.
      See Also:

    • renderUnique

      protected String renderUnique(UniqueNameConverter uniqueNameConverter, DDLTable table, DDLField field)
      Description copied from class: DatabaseProvider
      Renders the UNIQUE constraint as defined by the database-specific DDL syntax. This method is a delegate of other, more complex methods such as DatabaseProvider.renderField(net.java.ao.schema.NameConverters, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField, net.java.ao.DatabaseProvider.RenderFieldOptions). The default implementation just returns UNIQUE. Implementations may override this method to return an empty String if the database in question does not support the constraint.
      Overrides:
      renderUnique in class DatabaseProvider
      Returns:
      The database-specific rendering of UNIQUE.

    • parseValue

      public Object parseValue(int type, String value)
      Description copied from class: DatabaseProvider

      Parses the database-agnostic String value relevant to the specified SQL type in int form (as defined by Types and returns the Java value which corresponds. This method is completely database-agnostic, as are all of all of its delegate methods.

      WARNING: This method is being considered for removal to another class (perhaps TypeManager?) as it is not a database-specific function and thus confuses the purpose of this class. Do not rely upon it heavily. (better yet, don't rely on it at all from external code. It's not designed to be part of the public API)

      Overrides:
      parseValue in class DatabaseProvider
      Parameters:
      type - The JDBC integer type of the database field against which to parse the value.
      value - The database-agnostic String value to parse into a proper Java object with respect to the specified SQL type.
      Returns:
      A Java value which corresponds to the specified String.

    • getReservedWords

      protected Set<String> getReservedWords()
      Description copied from class: DatabaseProvider
      Retrieves the set of all reserved words for the underlying database. The set returns should be speculative, meaning that it should include any possible reserved words, not just those for a particular version. As an implementation guideline, the Set instance returned from this method should guarentee O(1) lookup times, otherwise ORM performance will suffer greatly.
      Specified by:
      getReservedWords in class DatabaseProvider
      Returns:
      A set of upper case reserved words specific to the database.

    • getH2VersionUtil

      public H2VersionUtil getH2VersionUtil()