Class IngresDialect

  • All Implemented Interfaces:
    ConversionContext
    Direct Known Subclasses:
    Ingres9Dialect

    public class IngresDialect
    extends Dialect
    An SQL dialect for Ingres 9.2.

    Known limitations:

    • Only supports simple constants or columns on the left side of an IN, making (1,2,3) in (...) or (subselect) in (...) non-supported.
    • Supports only 39 digits in decimal.
    • Explicitly set USE_GET_GENERATED_KEYS property to false.
    • Perform string casts to varchar; removes space padding.
    • Constructor Detail

      • IngresDialect

        public IngresDialect()
        Constructs a IngresDialect
    • Method Detail

      • getSelectGUIDString

        public java.lang.String getSelectGUIDString()
        Description copied from class: Dialect
        Get the command used to select a GUID from the underlying database.

        Optional operation.

        Overrides:
        getSelectGUIDString in class Dialect
        Returns:
        The appropriate command.
      • 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.
      • 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.
      • getNullColumnString

        public java.lang.String getNullColumnString()
        Description copied from class: Dialect
        The keyword used to specify a nullable column.
        Overrides:
        getNullColumnString in class Dialect
        Returns:
        String
      • 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.
      • 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.
      • 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.
      • 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
      • 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
      • getLowercaseFunction

        public java.lang.String getLowercaseFunction()
        Description copied from class: Dialect
        The name of the SQL function that transforms a string to lowercase
        Overrides:
        getLowercaseFunction in class Dialect
        Returns:
        The dialect-specific lowercase function.
      • getLimitHandler

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

        protected LimitHandler getDefaultLimitHandler()
      • 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.
      • supportsLimitOffset

        public boolean supportsLimitOffset()
        Description copied from class: Dialect
        Does this dialect's LIMIT support (if any) additionally support specifying an offset?
        Overrides:
        supportsLimitOffset in class Dialect
        Returns:
        True if the dialect supports an offset within the limit support.
      • getLimitString

        public java.lang.String getLimitString​(java.lang.String querySelect,
                                               int offset,
                                               int limit)
        Description copied from class: Dialect
        Given a limit and an offset, apply the limit clause to the query.
        Overrides:
        getLimitString in class Dialect
        Parameters:
        querySelect - The query to which to apply the limit.
        offset - The offset of the limit
        limit - The limit of the limit ;)
        Returns:
        The modified query statement with the limit applied.
      • supportsVariableLimit

        public boolean supportsVariableLimit()
        Description copied from class: Dialect
        Does this dialect support bind variables (i.e., prepared statement parameters) for its limit/offset?
        Overrides:
        supportsVariableLimit in class Dialect
        Returns:
        True if bind variables can be used; false otherwise.
      • useMaxForLimit

        public boolean useMaxForLimit()
        Description copied from class: Dialect
        Does the LIMIT clause take a "maximum" row number instead of a total number of returned rows?

        This is easiest understood via an example. Consider you have a table with 20 rows, but you only want to retrieve rows number 11 through 20. Generally, a limit with offset would say that the offset = 11 and the limit = 10 (we only want 10 rows at a time); this is specifying the total number of returned rows. Some dialects require that we instead specify offset = 11 and limit = 20, where 20 is the "last" row we want relative to offset (i.e. total number of rows = 20 - 11 = 9)

        So essentially, is limit relative from offset? Or is limit absolute?

        Overrides:
        useMaxForLimit in class Dialect
        Returns:
        True if limit is relative from offset; false otherwise.
      • getCurrentTimestampSQLFunctionName

        public java.lang.String getCurrentTimestampSQLFunctionName()
        Description copied from class: Dialect
        The name of the database-specific SQL function for retrieving the current timestamp.
        Overrides:
        getCurrentTimestampSQLFunctionName in class Dialect
        Returns:
        The function name.
      • supportsSubselectAsInPredicateLHS

        public boolean supportsSubselectAsInPredicateLHS()
        Description copied from class: Dialect
        Are subselects supported as the left-hand-side (LHS) of IN-predicates.

        In other words, is syntax like ... <subquery> IN (1, 2, 3) ... supported?

        Overrides:
        supportsSubselectAsInPredicateLHS in class Dialect
        Returns:
        True if subselects can appear as the LHS of an in-predicate; false otherwise.
      • 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.
      • 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 distinct tuples; false otherwise.