Package org.hibernate.dialect

Class PostgreSQLDialect

java.lang.Object
org.hibernate.dialect.Dialect
org.hibernate.dialect.PostgreSQLDialect
Direct Known Subclasses:
PostgresPlusDialect
public class PostgreSQLDialect extends Dialect
An SQL dialect for Postgres

For discussion of BLOB support in Postgres, as of 8.4, have a peek at http://jdbc.postgresql.org/documentation/84/binary-data.html. For the effects in regards to Hibernate see http://in.relation.to/15492.lace

  • Constructor Details

    • PostgreSQLDialect

      public PostgreSQLDialect()

  • Method Details

    • getAddColumnString

      public String getAddColumnString()
      Description copied from class: Dialect
      The syntax used to add a column to a table (optional).
      Overrides:
      getAddColumnString in class Dialect
      Returns:
      The "add column" fragment.

    • getSequenceNextValString

      public String getSequenceNextValString(String sequenceName)
      Description copied from class: Dialect
      Generate the appropriate select statement to to retrieve the next value of a sequence.

      This should be a "stand alone" select statement.

      Overrides:
      getSequenceNextValString in class Dialect
      Parameters:
      sequenceName - the name of the sequence
      Returns:
      String The "nextval" select string.

    • getSelectSequenceNextValString

      public String getSelectSequenceNextValString(String sequenceName)
      Description copied from class: Dialect
      Generate the select expression fragment that will retrieve the next value of a sequence as part of another (typically DML) statement.

      This differs from Dialect.getSequenceNextValString(String) in that this should return an expression usable within another statement.

      Overrides:
      getSelectSequenceNextValString in class Dialect
      Parameters:
      sequenceName - the name of the sequence
      Returns:
      The "nextval" fragment.

    • getCreateSequenceString

      public String getCreateSequenceString(String sequenceName)
      Description copied from class: Dialect
      Typically dialects which support sequences can create a sequence with a single command. This is convenience form of Dialect.getCreateSequenceStrings(java.lang.String) to help facilitate that.

      Dialects which support sequences and can create a sequence in a single command need *only* override this method. Dialects which support sequences but require multiple commands to create a sequence should instead override Dialect.getCreateSequenceStrings(java.lang.String).

      Overrides:
      getCreateSequenceString in class Dialect
      Parameters:
      sequenceName - The name of the sequence
      Returns:
      The sequence creation command

    • getDropSequenceString

      public String getDropSequenceString(String sequenceName)
      Description copied from class: Dialect
      Typically dialects which support sequences can drop a sequence with a single command. This is convenience form of Dialect.getDropSequenceStrings(java.lang.String) to help facilitate that.

      Dialects which support sequences and can drop a sequence in a single command need *only* override this method. Dialects which support sequences but require multiple commands to drop a sequence should instead override Dialect.getDropSequenceStrings(java.lang.String).

      Overrides:
      getDropSequenceString in class Dialect
      Parameters:
      sequenceName - The name of the sequence
      Returns:
      The sequence drop commands

    • getCascadeConstraintsString

      public String getCascadeConstraintsString()
      Description copied from class: Dialect
      Completely optional cascading drop clause
      Overrides:
      getCascadeConstraintsString in class Dialect
      Returns:
      String

    • dropConstraints

      public boolean dropConstraints()
      Description copied from class: Dialect
      Do we need to drop constraints before dropping tables in this dialect?
      Overrides:
      dropConstraints in class Dialect
      Returns:
      True if constraints must be dropped prior to dropping the table; false otherwise.

    • supportsSequences

      public boolean supportsSequences()
      Description copied from class: Dialect
      Does this dialect support sequences?
      Overrides:
      supportsSequences in class Dialect
      Returns:
      True if sequences supported; false otherwise.

    • getQuerySequencesString

      public String getQuerySequencesString()
      Description copied from class: Dialect
      Get the select command used retrieve the names of all sequences.
      Overrides:
      getQuerySequencesString in class Dialect
      Returns:
      The select command; or null if sequences are not supported.
      See Also:

    • supportsLimit

      public boolean supportsLimit()
      Description copied from class: Dialect
      Does this dialect support some form of limiting query results via a SQL clause?
      Overrides:
      supportsLimit in class Dialect
      Returns:
      True if this dialect supports some form of LIMIT.

    • getLimitString

      public String getLimitString(String sql, boolean hasOffset)
      Description copied from class: Dialect
      Apply s limit clause to the query.

      Typically dialects utilize variable limit clauses when they support limits. Thus, when building the select command we do not actually need to know the limit or the offest since we will just be using placeholders.

      Here we do still pass along whether or not an offset was specified so that dialects not supporting offsets can generate proper exceptions. In general, dialects will override one or the other of this method and Dialect.getLimitString(String, int, int).

      Overrides:
      getLimitString in class Dialect
      Parameters:
      sql - The query to which to apply the limit.
      hasOffset - Is the query requesting an offset?
      Returns:
      the modified SQL

    • bindLimitParametersInReverseOrder

      public boolean bindLimitParametersInReverseOrder()
      Description copied from class: Dialect
      ANSI SQL defines the LIMIT clause to be in the form LIMIT offset, limit. Does this dialect require us to bind the parameters in reverse order?
      Overrides:
      bindLimitParametersInReverseOrder in class Dialect
      Returns:
      true if the correct order is limit, offset

    • supportsIdentityColumns

      public boolean supportsIdentityColumns()
      Description copied from class: Dialect
      Does this dialect support identity column key generation?
      Overrides:
      supportsIdentityColumns in class Dialect
      Returns:
      True if IDENTITY columns are supported; false otherwise.

    • getForUpdateString

      public String getForUpdateString(String aliases)
      Description copied from class: Dialect
      Get the FOR UPDATE OF column_list fragment appropriate for this dialect given the aliases of the columns to be write locked.
      Overrides:
      getForUpdateString in class Dialect
      Parameters:
      aliases - The columns to be write locked.
      Returns:
      The appropriate FOR UPDATE OF column_list clause string.

    • getIdentitySelectString

      public String getIdentitySelectString(String table, String column, int type)
      Description copied from class: Dialect
      Get the select command to use to retrieve the last generated IDENTITY value for a particular table
      Overrides:
      getIdentitySelectString in class Dialect
      Parameters:
      table - The table into which the insert was done
      column - The PK column.
      type - The Types type code.
      Returns:
      The appropriate select command

    • getIdentityColumnString

      public String getIdentityColumnString(int type)
      Description copied from class: Dialect
      The syntax used during DDL to define a column as being an IDENTITY of a particular type.
      Overrides:
      getIdentityColumnString in class Dialect
      Parameters:
      type - The Types type code.
      Returns:
      The appropriate DDL fragment.

    • hasDataTypeInIdentityColumn

      public boolean hasDataTypeInIdentityColumn()
      Description copied from class: Dialect
      Whether this dialect have an Identity clause added to the data type or a completely separate identity data type
      Overrides:
      hasDataTypeInIdentityColumn in class Dialect
      Returns:
      boolean

    • getNoColumnsInsertString

      public String getNoColumnsInsertString()
      Description copied from class: Dialect
      The fragment used to insert a row without specifying any column values. This is not possible on some databases.
      Overrides:
      getNoColumnsInsertString in class Dialect
      Returns:
      The appropriate empty values clause.

    • getNativeIdentifierGeneratorClass

      public Class getNativeIdentifierGeneratorClass()
      Description copied from class: Dialect
      The class (which implements IdentifierGenerator) which acts as this dialects native generation strategy.

      Comes into play whenever the user specifies the native generator.

      Overrides:
      getNativeIdentifierGeneratorClass in class Dialect
      Returns:
      The native generator class.

    • supportsOuterJoinForUpdate

      public boolean supportsOuterJoinForUpdate()
      Description copied from class: Dialect
      Does this dialect support FOR UPDATE in conjunction with outer joined rows?
      Overrides:
      supportsOuterJoinForUpdate in class Dialect
      Returns:
      True if outer joined rows can be locked via FOR UPDATE.

    • useInputStreamToInsertBlob

      public boolean useInputStreamToInsertBlob()
      Description copied from class: Dialect
      Should LOBs (both BLOB and CLOB) be bound using stream operations (i.e. PreparedStatement.setBinaryStream(int, java.io.InputStream, int)).
      Overrides:
      useInputStreamToInsertBlob in class Dialect
      Returns:
      True if BLOBs and CLOBs should be bound using stream operations.

    • supportsUnionAll

      public boolean supportsUnionAll()
      Description copied from class: Dialect
      Does this dialect support UNION ALL, which is generally a faster variant of UNION?
      Overrides:
      supportsUnionAll in class Dialect
      Returns:
      True if UNION ALL is supported; false otherwise.

    • getSelectClauseNullString

      public String getSelectClauseNullString(int sqlType)
      Workaround for postgres bug #1453
      Overrides:
      getSelectClauseNullString in class Dialect
      Parameters:
      sqlType - The Types type code.
      Returns:
      The appropriate select clause value fragment.

    • supportsCommentOn

      public boolean supportsCommentOn()
      Overrides:
      supportsCommentOn in class Dialect

    • supportsTemporaryTables

      public boolean supportsTemporaryTables()
      Description copied from class: Dialect
      Does this dialect support temporary tables?
      Overrides:
      supportsTemporaryTables in class Dialect
      Returns:
      True if temp tables are supported; false otherwise.

    • getCreateTemporaryTableString

      public String getCreateTemporaryTableString()
      Description copied from class: Dialect
      Command used to create a temporary table.
      Overrides:
      getCreateTemporaryTableString in class Dialect
      Returns:
      The command used to create a temporary table.

    • getCreateTemporaryTablePostfix

      public String getCreateTemporaryTablePostfix()
      Description copied from class: Dialect
      Get any fragments needing to be postfixed to the command for temporary table creation.
      Overrides:
      getCreateTemporaryTablePostfix in class Dialect
      Returns:
      Any required postfix.

    • supportsCurrentTimestampSelection

      public boolean supportsCurrentTimestampSelection()
      Description copied from class: Dialect
      Does this dialect support a way to retrieve the database's current timestamp value?
      Overrides:
      supportsCurrentTimestampSelection in class Dialect
      Returns:
      True if the current timestamp can be retrieved; false otherwise.

    • isCurrentTimestampSelectStringCallable

      public boolean isCurrentTimestampSelectStringCallable()
      Description copied from class: Dialect
      Should the value returned by Dialect.getCurrentTimestampSelectString() be treated as callable. Typically this indicates that JDBC escape syntax is being used...
      Overrides:
      isCurrentTimestampSelectStringCallable in class Dialect
      Returns:
      True if the Dialect.getCurrentTimestampSelectString() return is callable; false otherwise.

    • getCurrentTimestampSelectString

      public String getCurrentTimestampSelectString()
      Description copied from class: Dialect
      Retrieve the command used to retrieve the current timestamp from the database.
      Overrides:
      getCurrentTimestampSelectString in class Dialect
      Returns:
      The command.

    • supportsTupleDistinctCounts

      public boolean supportsTupleDistinctCounts()
      Description copied from class: Dialect
      Does this dialect support `count(distinct a,b)`?
      Overrides:
      supportsTupleDistinctCounts in class Dialect
      Returns:
      True if the database supports counting disintct tuples; false otherwise.

    • toBooleanValueString

      public String toBooleanValueString(boolean bool)
      Description copied from class: Dialect
      The SQL literal value to which this database maps boolean values.
      Overrides:
      toBooleanValueString in class Dialect
      Parameters:
      bool - The boolean value
      Returns:
      The appropriate SQL literal.

    • getViolatedConstraintNameExtracter

      public ViolatedConstraintNameExtracter getViolatedConstraintNameExtracter()
      Overrides:
      getViolatedConstraintNameExtracter in class Dialect

    • registerResultSetOutParameter

      public int registerResultSetOutParameter(CallableStatement statement, int col) throws SQLException
      Description copied from class: Dialect
      Registers an OUT parameter which will be returning a ResultSet. How this is accomplished varies greatly from DB to DB, hence its inclusion (along with Dialect.getResultSet(java.sql.CallableStatement)) here.
      Overrides:
      registerResultSetOutParameter in class Dialect
      Parameters:
      statement - The callable statement.
      col - The bind position at which to register the OUT param.
      Returns:
      The number of (contiguous) bind positions used.
      Throws:
      SQLException - Indicates problems registering the OUT param.

    • getResultSet

      public ResultSet getResultSet(CallableStatement ps) throws SQLException
      Description copied from class: Dialect
      Given a callable statement previously processed by Dialect.registerResultSetOutParameter(java.sql.CallableStatement, int), extract the ResultSet from the OUT parameter.
      Overrides:
      getResultSet in class Dialect
      Parameters:
      ps - The callable statement.
      Returns:
      The extracted result set.
      Throws:
      SQLException - Indicates problems extracting the result set.

    • supportsPooledSequences

      public boolean supportsPooledSequences()
      Description copied from class: Dialect
      Does this dialect support "pooled" sequences. Not aware of a better name for this. Essentially can we specify the initial and increment values?
      Overrides:
      supportsPooledSequences in class Dialect
      Returns:
      True if such "pooled" sequences are supported; false otherwise.
      See Also:

    • getCreateSequenceString

      protected String getCreateSequenceString(String sequenceName, int initialValue, int incrementSize)
      Description copied from class: Dialect
      Overloaded form of Dialect.getCreateSequenceString(String), additionally taking the initial value and increment size to be applied to the sequence definition.

      The default definition is to suffix Dialect.getCreateSequenceString(String) with the string: " start with {initialValue} increment by {incrementSize}" where {initialValue} and {incrementSize} are replacement placeholders. Generally dialects should only need to override this method if different key phrases are used to apply the allocation information.
      Overrides:
      getCreateSequenceString in class Dialect
      Parameters:
      sequenceName - The name of the sequence
      initialValue - The initial value to apply to 'create sequence' statement
      incrementSize - The increment value to apply to 'create sequence' statement
      Returns:
      The sequence creation command

    • supportsEmptyInList

      public boolean supportsEmptyInList()
      Description copied from class: Dialect
      Does this dialect support empty IN lists?

      For example, is [where XYZ in ()] a supported construct?

      Overrides:
      supportsEmptyInList in class Dialect
      Returns:
      True if empty in lists are supported; false otherwise.

    • supportsExpectedLobUsagePattern

      public boolean supportsExpectedLobUsagePattern()
      Description copied from class: Dialect
      Expected LOB usage pattern is such that I can perform an insert via prepared statement with a parameter binding for a LOB value without crazy casting to JDBC driver implementation-specific classes...

      Part of the trickiness here is the fact that this is largely driver dependent. For example, Oracle (which is notoriously bad with LOB support in their drivers historically) actually does a pretty good job with LOB support as of the 10.2.x versions of their drivers...

      Overrides:
      supportsExpectedLobUsagePattern in class Dialect
      Returns:
      True if normal LOB usage patterns can be used with this driver; false if driver-specific hookiness needs to be applied.

    • supportsLobValueChangePropogation

      public boolean supportsLobValueChangePropogation()
      Description copied from class: Dialect
      Does the dialect support propagating changes to LOB values back to the database? Talking about mutating the internal value of the locator as opposed to supplying a new locator instance...

      For BLOBs, the internal value might be changed by: Blob.setBinaryStream(long), Blob.setBytes(long, byte[]), Blob.setBytes(long, byte[], int, int), or Blob.truncate(long).

      For CLOBs, the internal value might be changed by: Clob.setAsciiStream(long), Clob.setCharacterStream(long), Clob.setString(long, String), Clob.setString(long, String, int, int), or Clob.truncate(long).

      NOTE : I do not know the correct answer currently for databases which (1) are not part of the cruise control process or (2) do not Dialect.supportsExpectedLobUsagePattern().

      Overrides:
      supportsLobValueChangePropogation in class Dialect
      Returns:
      True if the changes are propagated back to the database; false otherwise.

    • supportsUnboundedLobLocatorMaterialization

      public boolean supportsUnboundedLobLocatorMaterialization()
      Description copied from class: Dialect
      Is it supported to materialize a LOB locator outside the transaction in which it was created?

      Again, part of the trickiness here is the fact that this is largely driver dependent.

      NOTE: all database I have tested which Dialect.supportsExpectedLobUsagePattern() also support the ability to materialize a LOB outside the owning transaction...

      Overrides:
      supportsUnboundedLobLocatorMaterialization in class Dialect
      Returns:
      True if unbounded materialization is supported; false otherwise.

    • getForUpdateString

      public String getForUpdateString()
      Description copied from class: Dialect
      Get the string to append to SELECT statements to acquire locks for this dialect.
      Overrides:
      getForUpdateString in class Dialect
      Returns:
      The appropriate FOR UPDATE clause string.

    • getWriteLockString

      public String getWriteLockString(int timeout)
      Description copied from class: Dialect
      Get the string to append to SELECT statements to acquire WRITE locks for this dialect. Location of the of the returned string is treated the same as getForUpdateString.
      Overrides:
      getWriteLockString in class Dialect
      Parameters:
      timeout - in milliseconds, -1 for indefinite wait and 0 for no wait.
      Returns:
      The appropriate LOCK clause string.

    • getReadLockString

      public String getReadLockString(int timeout)
      Description copied from class: Dialect
      Get the string to append to SELECT statements to acquire WRITE locks for this dialect. Location of the of the returned string is treated the same as getForUpdateString.
      Overrides:
      getReadLockString in class Dialect
      Parameters:
      timeout - in milliseconds, -1 for indefinite wait and 0 for no wait.
      Returns:
      The appropriate LOCK clause string.