Package org.eclipse.persistence.platform.database

Class HSQLPlatform

    • Constructor Detail

      • HSQLPlatform

        public HSQLPlatform()

    • Method Detail

      • toNumberOperator

        public static ExpressionOperator toNumberOperator()
        INTERNAL: Use CONVERT function for toNumber.

      • trimOperator

        public static ExpressionOperator trimOperator()
        INTERNAL: Use TRIM(FROM ?) function for trim.

      • rightTrim2

        protected ExpressionOperator rightTrim2()
        INTERNAL: Build HSQL equivalent to RTRIM(string_exp, character). HSQL: TRIM(TRAILING character FROM string_exp)

      • greatest

        protected ExpressionOperator greatest()
        INTERNAL: Build HSQL equivalent to GREATEST(x, y) HSQL: CASE WHEN x >= y THEN x ELSE y

      • supportsUniqueColumns

        public boolean supportsUniqueColumns()
        HSQL (1.8.1) does not support the UNIQUE key word in a column, but does support unique constraints defined separately. This allows the column setting to be generated as a constraint.
        Overrides:
        supportsUniqueColumns in class DatabasePlatform

      • supportsIdentity

        public boolean supportsIdentity()
        Description copied from class: DatasourcePlatform
        INTERNAL: Indicates whether the platform supports identity. This method is to be used *ONLY* by sequencing classes
        Overrides:
        supportsIdentity in class DatasourcePlatform

      • buildSelectQueryForIdentity

        public ValueReadQuery buildSelectQueryForIdentity()
        Description copied from class: DatasourcePlatform
        INTERNAL: Returns query used to read back the value generated by Identity. This method is called when identity NativeSequence is connected, the returned query used until the sequence is disconnected. If the platform supportsIdentity then (at least) one of buildSelectQueryForIdentity methods should return non-null query.
        Overrides:
        buildSelectQueryForIdentity in class DatasourcePlatform

      • isDynamicSQLRequiredForFunctions

        public boolean isDynamicSQLRequiredForFunctions()
        INTERNAL HSQL has some issues with using parameters on certain functions and relations. This allows statements to disable binding only in these cases.
        Overrides:
        isDynamicSQLRequiredForFunctions in class DatabasePlatform

      • supportsNestingOuterJoins

        public boolean supportsNestingOuterJoins()
        Does not allow nesting outer joins, i.e. each join must be followed by the ON clause.
        Overrides:
        supportsNestingOuterJoins in class DatabasePlatform

      • supportsSequenceObjects

        public boolean supportsSequenceObjects()
        Description copied from class: DatasourcePlatform
        INTERNAL: Indicates whether the platform supports sequence objects. This method is to be used *ONLY* by sequencing classes
        Overrides:
        supportsSequenceObjects in class DatasourcePlatform

      • isAlterSequenceObjectSupported

        public boolean isAlterSequenceObjectSupported()
        Description copied from class: DatabasePlatform
        INTERNAL: Override this method if the platform supports sequence objects and it's possible to alter sequence object's increment in the database.
        Overrides:
        isAlterSequenceObjectSupported in class DatabasePlatform

      • buildSelectQueryForSequenceObject

        public ValueReadQuery buildSelectQueryForSequenceObject​(String seqName,
                                                        Integer size)
        Description copied from class: DatasourcePlatform
        INTERNAL: Returns query used to read value generated by sequence object (like Oracle sequence). In case the other version of this method (taking no parameters) returns null, this method is called every time sequence object NativeSequence reads. If the platform supportsSequenceObjects then (at least) one of buildSelectQueryForSequenceObject methods should return non-null query.
        Overrides:
        buildSelectQueryForSequenceObject in class DatasourcePlatform

      • supportsGlobalTempTables

        public boolean supportsGlobalTempTables()
        Description copied from class: DatabasePlatform
        INTERNAL: Indicates whether the platform supports global temporary tables. "Global" means that an attempt to create temporary table with the same name for the second time results in exception. EclipseLink attempts to create global temporary table in the beginning of UpdateAllQuery, execution and assumes that it already exists in case SQLException results. In the end of UpdateAllQuery execution all rows are removed from the temporary table - it is necessary in case the same temporary table will be used by another UpdateAllQuery in the same transaction. Override this method if the platform supports global temporary tables. Note that this method is ignored in case supportsLocalTempTables() returns true.
        Overrides:
        supportsGlobalTempTables in class DatabasePlatform

      • getCreateTempTableSqlPrefix

        protected String getCreateTempTableSqlPrefix()
        Description copied from class: DatabasePlatform
        INTERNAL: Override this method if the platform supports temporary tables. This should contain the beginning of sql string for creating temporary table - the sql statement name, for instance: "CREATE GLOBAL TEMPORARY TABLE ". Don't forget to end it with a space.
        Overrides:
        getCreateTempTableSqlPrefix in class DatabasePlatform

      • writeUpdateOriginalFromTempTableSql

        public void writeUpdateOriginalFromTempTableSql​(Writer writer,
                                                DatabaseTable table,
                                                Collection pkFields,
                                                Collection assignedFields)
                                         throws IOException
        INTERNAL: HSQL does not allow multiple fields to be set as a list, so each field needs to be set one by one.
        Overrides:
        writeUpdateOriginalFromTempTableSql in class DatabasePlatform
        Parameters:
        writer - for writing the sql
        table - is original table for which temp table is created.
        pkFields - primary key fields for the original table.
        assignedFields - fields to be assigned a new value.
        Throws:
        IOException

      • computeMaxRowsForSQL

        public int computeMaxRowsForSQL​(int firstResultIndex,
                                int maxResults)
        INTERNAL: Use the JDBC maxResults and firstResultIndex setting to compute a value to use when limiting the results of a query in SQL. These limits tend to be used in two ways. 1. MaxRows is the index of the last row to be returned (like JDBC maxResults) 2. MaxRows is the number of rows to be returned HSQL uses case #2 and therefore the maxResults has to be altered based on the firstResultIndex.
        Overrides:
        computeMaxRowsForSQL in class DatabasePlatform
        See Also:
        MySQLPlatform