net.java.ao.DatabaseProvider
net.java.ao.db.PostgreSQLDatabaseProvider
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java.lang.Object
public class PostgreSQLDatabaseProvider
| Field Summary |
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| Fields inherited from class net.java.ao.DatabaseProvider |
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eventManager |
| Constructor Summary | |
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PostgreSQLDatabaseProvider(DisposableDataSource dataSource)
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| Method Summary | ||
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protected boolean |
considerPrecision(DDLField field)
Determines whether or not the database allows explicit precisions for the field in question. |
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protected String |
convertTypeToString(DatabaseType<?> type)
Converts the specified type into the database-specific DDL String value. |
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protected
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executeInsertReturningKey(EntityManager manager,
Connection conn,
Class<T> pkType,
String pkField,
String sql,
DBParam... params)
Delegate method to execute an INSERT statement returning any auto-generated primary key values. |
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protected String |
getFunctionNameForField(DDLTable table,
DDLField field)
Retrieves the name of the function which corresponds to the field in question (if any). |
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protected Set<String> |
getReservedWords()
Retrieves the set of all reserved words for the underlying database. |
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ResultSet |
getTables(Connection conn)
Returns a result set of all of the tables (and associated meta) in the database. |
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protected String |
getTriggerNameForField(DDLTable table,
DDLField field)
Retrieves the name of the trigger which corresponds to the field in question (if any). |
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Object |
handleBlob(ResultSet res,
Class<?> type,
String field)
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void |
handleUpdateError(SQLException e)
Tells whether this exception should be ignored when running an updated statement. |
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insertReturningKey(EntityManager manager,
Connection conn,
Class<T> pkType,
String pkField,
boolean pkIdentity,
String table,
DBParam... params)
Generates an INSERT statement to be used to create a new row in the database, returning the primary key value. |
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Object |
parseValue(int type,
String value)
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. |
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void |
putNull(PreparedStatement stmt,
int index)
Stores an SQL NULL value in the database. |
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protected String[] |
renderAlterTableChangeColumn(DDLTable table,
DDLField oldField,
DDLField field)
Generates the database-specific DDL statements required to change the given column from its old specification to the given DDL value. |
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protected String |
renderAlterTableDropKey(DDLForeignKey key)
Generates the database-specific DDL statement required to remove a foreign key from a table. |
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protected String |
renderAutoIncrement()
Generates the DDL fragment required to specify an INTEGER field as auto-incremented. |
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protected String[] |
renderDropFunctions(DDLTable table)
Generates the database-specific DDL statements required to drop all associated functions for the given table representation. |
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protected String |
renderDropIndex(DDLIndex index)
Generates the database-specific DDL statement required to drop an index. |
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protected String |
renderFieldType(DDLField field)
Renders the database-specific DDL type for the field in question. |
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protected String |
renderFunction(DatabaseFunction func)
Renders the specified DatabaseFunction in its
database-specific form. |
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protected String |
renderFunctionForField(DDLTable table,
DDLField field)
Renders the function which corresponds to the specified field, or null if none. |
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protected String |
renderOnUpdate(DDLField field)
Renders the appropriate field suffix to allow for the OnUpdate functionality. |
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protected String |
renderTriggerForField(DDLTable table,
DDLField field)
Renders the trigger which corresponds to the specified field, or null if none. |
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protected String |
renderValue(Object value)
Renders the given Java instance in a database-specific way. |
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protected boolean |
shouldQuoteID(String id)
Determines whether or not the specified identifier should be quoted before transmission to the underlying database. |
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| Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
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public PostgreSQLDatabaseProvider(DisposableDataSource dataSource)
| Method Detail |
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protected boolean considerPrecision(DDLField field)
DatabaseProviderDetermines whether or not the database allows explicit precisions
for the field in question. This is to support databases such as
Derby which do not support precisions for certain types. By
default, this method returns true.
More often than not, all that is required for this determination is the type. As such, the method signature may change in a future release.
considerPrecision in class DatabaseProviderfield - The field for which precision should/shouldn't be rendered.
true if precision should be rendered, otherwise
false.
public Object parseValue(int type,
String value)
DatabaseProviderParses 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)
parseValue in class DatabaseProvidertype - 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.
public ResultSet getTables(Connection conn)
throws SQLException
DatabaseProviderReturns a result set of all of the tables (and associated
meta) in the database. The fields of the result set must
correspond with those specified in the
DatabaseMetaData#getTables(String, String, String, String[])
method. In fact, the default implementation merely calls
this method passing (null, null, "", null).
For databases (such as PostgreSQL) where this is unsuitable,
different parameters can be specified to the getTables
method in the override, or an entirely new implementation
written, as long as the result set corresponds in fields to
the JDBC spec.
getTables in class DatabaseProviderconn - The connection to use in retrieving the database tables.
SQLExceptionDatabaseMetaData.getTables(String, String, String, String[])protected String renderAutoIncrement()
DatabaseProviderGenerates the DDL fragment required to specify an INTEGER field as
auto-incremented. For databases which do not support such flags (which
is just about every database exception MySQL), "" is an
acceptable return value. This method should never return null
as it would cause the field rendering method to throw a NullPointerException.
renderAutoIncrement in class DatabaseProviderprotected String renderFieldType(DDLField field)
DatabaseProviderDatabaseProvider.convertTypeToString(DatabaseType)
method, passing the field type. Thus, it is rarely necessary
(if ever) to override this method. It may be deprecated in a
future release.
renderFieldType in class DatabaseProviderfield - The field which contains the type to be rendered.
protected String convertTypeToString(DatabaseType<?> type)
DatabaseProviderDatabaseType#getDefaultName()
method. Subclass implementations should be sure to make a super
call in order to ensure that both default naming and future special
cases are handled appropriately.
convertTypeToString in class DatabaseProvidertype - The type instance to convert to a DDL string.
DatabaseType.getDefaultName()protected String renderValue(Object value)
DatabaseProviderCalendar,
Boolean (which is always rendered as 0/1), functions,
null and numbers. All other values are rendered (by
default) as 'value.toString()' (the String value
enclosed within single quotes). Implementations are encouraged to
override this method as necessary.
renderValue in class DatabaseProvidervalue - The Java instance to be rendered as a database literal.
DatabaseProvider.renderCalendar(Calendar),
DatabaseProvider.renderFunction(DatabaseFunction)protected String renderFunction(DatabaseFunction func)
DatabaseProviderRenders the specified DatabaseFunction in its
database-specific form. For example, for MySQL the
CURRENT_DATE enum value would be rendered as
"CURRENT_DATE" (without the quotes). For functions
which do not have a database equivalent, a default literal value
of the appropriate type should be returned. For example, if MySQL
did not define either a CURRENT_DATE or a CURRENT_TIMESTAMP
function, the appropriate return value for both functions would
be '0000-00-00 00:00:00' (including the quotes).
This is to prevent migrations from failing even in cases where
non-standard functions are used.
As of 1.0, no unconventional functions are allowed by the
DatabaseFunction enum, thus no database should have any
problems with any allowed functions.
renderFunction in class DatabaseProviderfunc - The abstract function to be rendered.
protected String renderFunctionForField(DDLTable table,
DDLField field)
DatabaseProvidernull if none. This is to allow for databases which
require the use of triggers and explicitly created functions to
provide functionality such as ON UPDATE (e.g. PostgreSQL). The
default implementation returns null.
renderFunctionForField in class DatabaseProvidertable - The table containing the field for which a function
may need to be rendered.field - The field for which the function should be rendered,
if any.
null.DatabaseProvider.getFunctionNameForField(DDLTable, DDLField)
protected String renderTriggerForField(DDLTable table,
DDLField field)
DatabaseProvidernull if none. This is to allow for databases which
require the use of triggers to provide functionality such as ON
UPDATE. The default implementation returns null.
renderTriggerForField in class DatabaseProvidertable - The table containing the field for which a trigger
may need to be rendered.field - The field for which the trigger should be rendered,
if any.
null.DatabaseProvider.getTriggerNameForField(DDLTable, DDLField)protected String renderOnUpdate(DDLField field)
DatabaseProviderRenders the appropriate field suffix to allow for the
OnUpdate functionality. For most databases (read:
all but MySQL) this will return an empty String. This is
because few databases provide an implicit ON UPDATE syntax for
fields. As such, most databases will be compelled to return
an empty String and implement the functionality using triggers.
renderOnUpdate in class DatabaseProviderfield - The field for which the ON UPDATE clause should
be rendered.
public Object handleBlob(ResultSet res,
Class<?> type,
String field)
throws SQLException
handleBlob in class DatabaseProviderSQLException
protected String[] renderAlterTableChangeColumn(DDLTable table,
DDLField oldField,
DDLField field)
DatabaseProviderGenerates 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(DDLTable, DDLField, DDLField)
method.
renderAlterTableChangeColumn in class DatabaseProvidertable - The table containing the column to change.oldField - The old column definition.field - The new column definition (defining the resultant DDL).
DatabaseProvider.getTriggerNameForField(DDLTable, DDLField),
DatabaseProvider.getFunctionNameForField(DDLTable, DDLField),
DatabaseProvider.renderFunctionForField(DDLTable, DDLField),
DatabaseProvider.renderTriggerForField(DDLTable, DDLField)protected String renderAlterTableDropKey(DDLForeignKey key)
DatabaseProvidernull value returned. This method assumes that the
DatabaseProvider.renderForeignKey(DDLForeignKey) method properly names
the foreign key according to the DDLForeignKey.getFKName()
method.
renderAlterTableDropKey in class DatabaseProviderkey - The foreign key to be removed. As this instance contains
all necessary data (such as domestic table, field, etc), no
additional parameters are required.
null.protected String renderDropIndex(DDLIndex index)
DatabaseProvidernull returned.
renderDropIndex in class DatabaseProviderindex - 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.
null.protected String[] renderDropFunctions(DDLTable table)
DatabaseProvider
renderDropFunctions in class DatabaseProvidertable - The table representation against which all functions which
correspond (directly or indirectly) must be dropped.
protected String getFunctionNameForField(DDLTable table,
DDLField field)
DatabaseProvidernull should be returned.
This method is to allow for databases which require the use of
explicitly created functions which correspond to triggers (e.g.
PostgreSQL). Few providers will need to override the default
implementation of this method, which returns null.
getFunctionNameForField in class DatabaseProvidertable - The table which contains the field for which a function
may or may not exist.field - The field for which a previous migration may have
created a function.
null if none.
protected String getTriggerNameForField(DDLTable table,
DDLField field)
DatabaseProvidernull should be returned.
This function is to allow for databases which require the use of
triggers on a field to allow for certain functionality (like
ON UPDATE). The default implementation returns null.
getTriggerNameForField in class DatabaseProvidertable - The table which contains the field for which a trigger
may or may not exist.field - The field for which a previous migration may have
created a trigger.
null if none.DatabaseProvider.renderTriggerForField(DDLTable, DDLField)
public <T> T insertReturningKey(EntityManager manager,
Connection conn,
Class<T> pkType,
String pkField,
boolean pkIdentity,
String table,
DBParam... params)
throws SQLException
DatabaseProviderGenerates an INSERT statement to be used to create a new row in the
database, returning the primary key value. This method also invokes
the delegate method, DatabaseProvider.executeInsertReturningKey(EntityManager, Connection, Class, String, String, DBParam...)
passing the appropriate parameters and query. This method is required
because some databases do not support the JDBC parameter
RETURN_GENERATED_KEYS (such as HSQLDB and PostgreSQL).
Also, some databases (such as MS SQL Server) require odd tricks to
support explicit value passing to auto-generated fields. This method
should take care of any extra queries or odd SQL generation required
to implement both auto-generated primary key returning, as well as
explicit primary key value definition.
Overriding implementations of this method should be sure to use the
Connection instance passed to the method, not a new
instance generated using the DatabaseProvider.getConnection() method. This is
because this method is in fact a delegate invoked by EntityManager
as part of the entity creation process and may be part of a transaction,
a bulk creation or some more complicated operation. Both optimization
and usage patterns on the API dictate that the specified connection
instance be used. Implementations may assume that the given connection
instance is never null.
The default implementation of this method should be sufficient for any
fully compliant ANSI SQL database with a properly implemented JDBC
driver. Note that this method should not not actually execute
the SQL it generates, but pass it on to the DatabaseProvider.executeInsertReturningKey(EntityManager, Connection, Class, String, String, DBParam...)
method, allowing for functional delegation and better extensibility.
However, this method may execute any additional statements required to
prepare for the INSERTion (as in the case of MS SQL Server which requires
some config parameters to be set on the database itself prior to INSERT).
insertReturningKey in class DatabaseProvidermanager - The EntityManager which was used to dispatch
the INSERT in question.conn - The connection to be used in the eventual execution of the
generated SQL statement.pkType - The Java type of the primary key value. Can be used to
perform a linear search for a specified primary key value in the
params list. The return value of the method must be of
the same type.pkField - The database field which is the primary key for the
table in question. Can be used to perform a linear search for a
specified primary key value in the params list.pkIdentity - Flag indicating whether or not the primary key field
is auto-incremented by the database (IDENTITY field).table - The name of the table into which the row is to be INSERTed.params - A varargs array of parameters to be passed to the
INSERT statement. This may include a specified value for the
primary key.
SQLException - If the INSERT fails in the delegate method, or
if any additional statements fail with an exception.DatabaseProvider.executeInsertReturningKey(EntityManager, Connection, Class, String, String, DBParam...)
protected <T> T executeInsertReturningKey(EntityManager manager,
Connection conn,
Class<T> pkType,
String pkField,
String sql,
DBParam... params)
throws SQLException
DatabaseProviderDelegate method to execute an INSERT statement returning any auto-generated
primary key values. This method is primarily designed to be called as a delegate
from the DatabaseProvider.insertReturningKey(EntityManager, Connection, Class, String, boolean, String, DBParam...)
method. The idea behind this method is to allow custom implementations to
override this method to potentially execute other statements (such as getting the
next value in a sequence) rather than the default implementaiton which uses the
JDBC constant, RETURN_GENERATED_KEYS. Any database which has a
fully-implemented JDBC driver should have no problems with the default
implementation of this method.
Part of the design behind splitting insertReturningKey and
executeInsertReturningKey is so that logic for generating the actual
INSERT statement need not be duplicated throughout the code and in custom
implementations providing trivial changes to the default algorithm. This method
should avoid actually generating SQL if at all possible.
This method should iterate through the passed DBParam(s) to
ensure that no primary key value was explicitly specified. If one was, it
should be used in leiu of one which is auto-generated by the database. Also,
it is this value which should be returned if specified, rather than the value
which would have been generated or null. As such, this method
should always return exactly the value of the primary key field in the row which
was just inserted, regardless of what that value may be.
In cases where the database mechanism for getting the next primary key value
is not thread safe, this method should be declared synchronized,
or some thread synchronization technique employed. Unfortunately, it is not
always possible to ensure that no other INSERT could (potentially) "steal" the
expected value out from under the algorithm. Such scenarios are to be avoided
when possible, but the algorithm need not take extremely escoteric concurrency
cases into account. (see the HSQLDB provider for an example of such a
less-than-thorough asynchronous algorithm)
IMPORTANT: The INSERT Statement must use the specified
connection, rather than a new one retrieved from DatabaseProvider.getConnection() or
equivalent. This is because the INSERT may be part of a bulk insertion, a
transaction, or possibly another such operation. It is also important to note
that this method should not close the connection. Doing so could cause the
entity creation algorithm to fail at a higher level up the stack.
executeInsertReturningKey in class DatabaseProvidermanager - The EntityManager which was used to dispatch
the INSERT in question.conn - The database connection to use in executing the INSERT statement.pkType - The Java class type of the primary key field (for use both in
searching the params as well as performing value conversion
of auto-generated DB values into proper Java instances).pkField - The database field which is the primary key for the
table in question. Can be used to perform a linear search for a
specified primary key value in the params list.params - A varargs array of parameters to be passed to the
INSERT statement. This may include a specified value for the
primary key.
SQLException - If the INSERT fails in the delegate method, or
if any additional statements fail with an exception.DatabaseProvider.insertReturningKey(EntityManager, Connection, Class, String, boolean, String, DBParam...)
public void putNull(PreparedStatement stmt,
int index)
throws SQLException
DatabaseProviderNULL value in the database. This method
is required due to the fact that not all JDBC drivers handle NULLs
in the same fashion. The default implementation calls PreparedStatement.setString(int, String),
passing null as a value. Databases which require a
different implementation (e.g. PostgreSQL) should override this method.
putNull in class DatabaseProviderstmt - The statement in which to store the NULL value.index - The index of the parameter which should be assigned NULL.
SQLExceptionprotected Set<String> getReservedWords()
DatabaseProviderSet instance returned from this
method should guarentee O(1) lookup times, otherwise ORM performance
will suffer greatly.
getReservedWords in class DatabaseProviderprotected boolean shouldQuoteID(String id)
DatabaseProviderDatabaseProvider.getReservedWords(). Databases with more complicated
rules regarding quoting should provide a custom implementation of this
method.
shouldQuoteID in class DatabaseProviderid - The identifier to check against the quoting rules.
true if the specified identifier is invalid under
the relevant quoting rules, otherwise false.
public void handleUpdateError(SQLException e)
throws SQLException
DatabaseProvider
handleUpdateError in class DatabaseProvidere - the SQLException that occured.
SQLException - throws the SQLException if it should not be ignored.
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