Package org.hibernate.dialect

Class H2Dialect

    • Constructor Detail

      • H2Dialect

        public H2Dialect()
        Constructs a H2Dialect

    • Method Detail

      • getAddColumnString

        public java.lang.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.

      • getForUpdateString

        public java.lang.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.

      • getLimitHandler

        public LimitHandler getLimitHandler()
        Description copied from class: Dialect
        Returns the delegate managing LIMIT clause.
        Overrides:
        getLimitHandler in class Dialect
        Returns:
        LIMIT clause delegate.

      • 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 java.lang.String getLimitString​(java.lang.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

      • bindLimitParametersFirst

        public boolean bindLimitParametersFirst()
        Description copied from class: Dialect
        Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?
        Overrides:
        bindLimitParametersFirst in class Dialect
        Returns:
        true if limit parameters should come before other parameters

      • supportsIfExistsAfterTableName

        public boolean supportsIfExistsAfterTableName()
        Description copied from class: Dialect
        For dropping a table, can the phrase "if exists" be applied after the table name?

        NOTE : Only one or the other (or neither) of this and Dialect.supportsIfExistsBeforeTableName() should return true

        Overrides:
        supportsIfExistsAfterTableName in class Dialect
        Returns:
        true if the "if exists" can be applied after the table name

      • supportsIfExistsBeforeConstraintName

        public boolean supportsIfExistsBeforeConstraintName()
        Description copied from class: Dialect
        For dropping a constraint with an "alter table", can the phrase "if exists" be applied before the constraint name?

        NOTE : Only one or the other (or neither) of this and Dialect.supportsIfExistsAfterConstraintName() should return true

        Overrides:
        supportsIfExistsBeforeConstraintName in class Dialect
        Returns:
        true if the "if exists" can be applied before the constraint name

      • 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.

      • getCreateSequenceString

        public java.lang.String getCreateSequenceString​(java.lang.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 java.lang.String getDropSequenceString​(java.lang.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

      • getSelectSequenceNextValString

        public java.lang.String getSelectSequenceNextValString​(java.lang.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.

      • getSequenceNextValString

        public java.lang.String getSequenceNextValString​(java.lang.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.

      • getQuerySequencesString

        public java.lang.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:
        SchemaUpdate

      • buildSQLExceptionConversionDelegate

        public SQLExceptionConversionDelegate buildSQLExceptionConversionDelegate()
        Description copied from class: Dialect
        Build an instance of a SQLExceptionConversionDelegate for interpreting dialect-specific error or SQLState codes.

        When Dialect.buildSQLExceptionConverter() returns null, the default SQLExceptionConverter is used to interpret SQLState and error codes. If this method is overridden to return a non-null value, the default SQLExceptionConverter will use the returned SQLExceptionConversionDelegate in addition to the following standard delegates:

        1. a "static" delegate based on the JDBC 4 defined SQLException hierarchy;
        2. a delegate that interprets SQLState codes for either X/Open or SQL-2003 codes, depending on java.sql.DatabaseMetaData#getSQLStateType

        It is strongly recommended that specific Dialect implementations override this method, since interpretation of a SQL error is much more accurate when based on the a vendor-specific ErrorCode rather than the SQLState.

        Specific Dialects may override to return whatever is most appropriate for that vendor.

        Overrides:
        buildSQLExceptionConversionDelegate in class Dialect
        Returns:
        The SQLExceptionConversionDelegate for this dialect

      • 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.

      • getCurrentTimestampSelectString

        public java.lang.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.

      • 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.

      • 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.

      • doesReadCommittedCauseWritersToBlockReaders

        public boolean doesReadCommittedCauseWritersToBlockReaders()
        Description copied from class: Dialect
        For the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?
        Overrides:
        doesReadCommittedCauseWritersToBlockReaders in class Dialect
        Returns:
        True if writers block readers to achieve READ_COMMITTED; false otherwise.

      • supportsTuplesInSubqueries

        public boolean supportsTuplesInSubqueries()
        Description copied from class: Dialect
        Does this dialect support tuples in subqueries? Ex: delete from Table1 where (col1, col2) in (select col1, col2 from Table2)
        Overrides:
        supportsTuplesInSubqueries in class Dialect
        Returns:
        boolean

      • 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.

      • getQueryHintString

        public java.lang.String getQueryHintString​(java.lang.String query,
                                           java.lang.String hints)
        Description copied from class: Dialect
        Apply a hint to the query. The entire query is provided, allowing the Dialect full control over the placement and syntax of the hint. By default, ignore the hint and simply return the query.
        Overrides:
        getQueryHintString in class Dialect
        Parameters:
        query - The query to which to apply the hint.
        hints - The hints to apply
        Returns:
        The modified SQL