Package org.hibernate.dialect

Class DB2zDialect

    • Method Detail

      • initializeFunctionRegistry

        public void initializeFunctionRegistry​(FunctionContributions functionContributions)
        Description copied from class: Dialect
        Initialize the given registry with any dialect-specific functions.

        Support for certain SQL functions is required, and if the database does not support a required function, then the dialect must define a way to emulate it.

        These required functions include the functions defined by the JPA query language specification:

        • avg(arg) - aggregate function
        • count([distinct ]arg) - aggregate function
        • max(arg) - aggregate function
        • min(arg) - aggregate function
        • sum(arg) - aggregate function
        • coalesce(arg0, arg1, ...)
        • nullif(arg0, arg1)
        • lower(arg)
        • upper(arg)
        • length(arg)
        • concat(arg0, arg1, ...)
        • locate(pattern, string[, start])
        • substring(string, start[, length])
        • trim([[spec ][character ]from] string)
        • abs(arg)
        • mod(arg0, arg1)
        • sqrt(arg)
        • current date
        • current time
        • current timestamp
        Along with an additional set of functions defined by ANSI SQL:
        • any(arg) - aggregate function
        • every(arg) - aggregate function
        • var_samp(arg) - aggregate function
        • var_pop(arg) - aggregate function
        • stddev_samp(arg) - aggregate function
        • stddev_pop(arg) - aggregate function
        • cast(arg as Type)
        • extract(field from arg)
        • ln(arg)
        • exp(arg)
        • power(arg0, arg1)
        • floor(arg)
        • ceiling(arg)
        • position(pattern in string)
        • substring(string from start[ for length])
        • overlay(string placing replacement from start[ for length])
        And the following functions for working with java.time types:
        • local date
        • local time
        • local datetime
        • offset datetime
        • instant
        And a number of additional "standard" functions:
        • left(string, length)
        • right(string, length)
        • replace(string, pattern, replacement)
        • pad(string with length spec[ character])
        • repeat(string, times)
        • pi
        • log10(arg)
        • log(base, arg)
        • sign(arg)
        • sin(arg)
        • cos(arg)
        • tan(arg)
        • asin(arg)
        • acos(arg)
        • atan(arg)
        • atan2(arg0, arg1)
        • round(arg0[, arg1])
        • truncate(arg0[, arg1])
        • sinh(arg)
        • tanh(arg)
        • cosh(arg)
        • least(arg0, arg1, ...)
        • greatest(arg0, arg1, ...)
        • degrees(arg)
        • radians(arg)
        • format(datetime as pattern)
        • collate(string as collation)
        • str(arg) - synonym of cast(a as String)
        • ifnull(arg0, arg1) - synonym of coalesce(a, b)
        Finally, the following functions are defined as abbreviations for extract(), and desugared by the parser:
        • second(arg) - synonym of extract(second from a)
        • minute(arg) - synonym of extract(minute from a)
        • hour(arg) - synonym of extract(hour from a)
        • day(arg) - synonym of extract(day from a)
        • month(arg) - synonym of extract(month from a)
        • year(arg) - synonym of extract(year from a)
        Note that according to this definition, the second() function returns a floating point value, contrary to the integer type returned by the native function with this name on many databases. Thus, we don't just naively map these HQL functions to the native SQL functions with the same names.
        Overrides:
        initializeFunctionRegistry in class DB2Dialect

      • getCreateIndexString

        public String getCreateIndexString​(boolean unique)
        Description copied from class: Dialect
        The command used to create an index, usually create index or create unique index.
        Overrides:
        getCreateIndexString in class Dialect
        Parameters:
        unique - true if the index is a unique index
        Returns:
        The command used to create an index.

      • getCreateIndexTail

        public String getCreateIndexTail​(boolean unique,
                                 List<Column> columns)
        Description copied from class: Dialect
        A string to be appended to the end of the create index command, usually to specify that null values are to be considered distinct.
        Overrides:
        getCreateIndexTail in class DB2Dialect

      • supportsDistinctFromPredicate

        public boolean supportsDistinctFromPredicate()
        Description copied from class: Dialect
        Does this dialect support some kind of distinct from predicate?

        That is, does it support syntax like: 

         ... where FIRST_NAME IS DISTINCT FROM LAST_NAME
        Overrides:
        supportsDistinctFromPredicate in class DB2Dialect
        Returns:
        True if this SQL dialect is known to support some kind of distinct from predicate; 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 DB2Dialect
        Returns:
        The select command; or null if sequences are not supported.

      • supportsSkipLocked

        public boolean supportsSkipLocked()
        Description copied from class: Dialect
        Does this dialect support SKIP_LOCKED timeout.
        Overrides:
        supportsSkipLocked in class DB2Dialect
        Returns:
        true if SKIP_LOCKED is supported

      • supportsLateral

        public boolean supportsLateral()
        Description copied from class: Dialect
        Does this dialect support the SQL lateral keyword or a proprietary alternative?
        Overrides:
        supportsLateral in class DB2Dialect
        Returns:
        true if the underlying database supports lateral, false otherwise. The default is false.

      • supportsRecursiveCTE

        public boolean supportsRecursiveCTE()
        Description copied from class: Dialect
        Does this dialect/database support recursive CTEs?
        Overrides:
        supportsRecursiveCTE in class DB2Dialect
        Returns:
        true if recursive CTEs are supported

      • timestampaddPattern

        public String timestampaddPattern​(TemporalUnit unit,
                                  TemporalType temporalType,
                                  IntervalType intervalType)
        Description copied from class: Dialect
        Obtain a pattern for the SQL equivalent to a timestampadd() function call. The resulting pattern must contain ?1, ?2, and ?3 placeholders for the arguments.
        Overrides:
        timestampaddPattern in class DB2Dialect
        Parameters:
        unit - The unit to add to the temporal
        temporalType - The type of the temporal
        intervalType - The type of interval to add or null if it's not a native interval

      • rowIdSqlType

        public int rowIdSqlType()
        Description copied from class: Dialect
        The JDBC type code of the rowid-like pseudo-column which acts as a high-performance row locator.
        Overrides:
        rowIdSqlType in class DB2Dialect
        Returns:
        Types.ROWID by default

      • getRowIdColumnString

        public String getRowIdColumnString​(String rowId)
        Description copied from class: Dialect
        If this dialect requires that the rowid column be declared explicitly, return the DDL column definition.
        Overrides:
        getRowIdColumnString in class Dialect
        Returns:
        the DDL column definition, or null if the rowid is an implicit pseudo-column