Package org.hibernate.dialect

Class PostgreSQLDialect

    • Method Detail

      • columnType

        protected String columnType​(int sqlTypeCode)
        Description copied from class: Dialect
        The column type name for a given JDBC type code defined in Types or SqlTypes. This default implementation returns the ANSI-standard type name.

        This method may be overridden by concrete Dialects as an alternative to Dialect.registerColumnTypes(TypeContributions, ServiceRegistry) for simple registrations.

        Overrides:
        columnType in class Dialect
        Parameters:
        sqlTypeCode - a SQL type code
        Returns:
        a column type name, with $l, $p, $s placeholders for length, precision, scale
        See Also:
        SqlTypes

      • getMaxVarcharLength

        public int getMaxVarcharLength()
        Description copied from class: Dialect
        The longest possible length of a Types.VARCHAR-like column. For longer column lengths, use some sort of text-like type for the column.
        Overrides:
        getMaxVarcharLength in class Dialect

      • getMaxVarbinaryLength

        public int getMaxVarbinaryLength()
        Description copied from class: Dialect
        The longest possible length of a Types.VARBINARY-like column. For longer column lengths, use some sort of image-like type for the column.
        Overrides:
        getMaxVarbinaryLength in class Dialect

      • currentTime

        public String currentTime()
        Description copied from class: Dialect
        Translation of the HQL/JPQL current_time function, which maps to the Java type java.sql.Time which is a time with no time zone. This contradicts ANSI SQL where current_time has the type TIME WITH TIME ZONE.

        It is recommended to override this in dialects for databases which support localtime or time at local.

        Overrides:
        currentTime in class Dialect

      • currentTimestamp

        public String currentTimestamp()
        Description copied from class: Dialect
        Translation of the HQL/JPQL current_timestamp function, which maps to the Java type java.sql.Timestamp which is a datetime with no time zone. This contradicts ANSI SQL where current_timestamp has the type TIMESTAMP WITH TIME ZONE.

        It is recommended to override this in dialects for databases which support localtimestamp or timestamp at local.

        Overrides:
        currentTimestamp in class Dialect

      • currentTimestampWithTimeZone

        public String currentTimestampWithTimeZone()
        Description copied from class: Dialect
        Translation of the HQL offset_datetime function, which maps to the Java type java.time.OffsetDateTime which is a datetime with a time zone. This in principle correctly maps to the ANSI SQL current_timestamp which has the type TIMESTAMP WITH TIME ZONE.
        Overrides:
        currentTimestampWithTimeZone in class Dialect

      • extractPattern

        public String extractPattern​(TemporalUnit unit)
        The extract() function returns TemporalUnit.DAY_OF_WEEK numbered from 0 to 6. This isn't consistent with what most other databases do, so here we adjust the result by generating (extract(dow,arg)+1)).
        Overrides:
        extractPattern in class Dialect
        Parameters:
        unit - the first argument

      • getFractionalSecondPrecisionInNanos

        public long getFractionalSecondPrecisionInNanos()
        microsecond is the smallest unit for an interval, and the highest precision for a timestamp, so we could use it as the "native" precision, but it's more convenient to use whole seconds (with the fractional part), since we want to use extract(epoch from ...) in our emulation of timestampdiff().
        Overrides:
        getFractionalSecondPrecisionInNanos in class Dialect
        Returns:
        the precision, specified as a quantity of nanoseconds
        See Also:
        TemporalUnit.NATIVE

      • 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 Dialect
        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

      • timestampdiffPattern

        public String timestampdiffPattern​(TemporalUnit unit,
                                   TemporalType fromTemporalType,
                                   TemporalType toTemporalType)
        Description copied from class: Dialect
        Obtain a pattern for the SQL equivalent to a timestampdiff() function call. The resulting pattern must contain ?1, ?2, and ?3 placeholders for the arguments.
        Overrides:
        timestampdiffPattern in class Dialect
        Parameters:
        unit - the first argument
        fromTemporalType - true if the first argument is a timestamp, false if a date
        toTemporalType - true if the second argument is

      • initializeFunctionRegistry

        public void initializeFunctionRegistry​(QueryEngine queryEngine)
        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
        • 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])
        • log10(arg)
        • sign(arg)
        • sin(arg)
        • cos(arg)
        • tan(arg)
        • asin(arg)
        • acos(arg)
        • atan(arg)
        • atan2(arg0, arg1)
        • round(arg0, arg1)
        • least(arg0, arg1, ...)
        • greatest(arg0, arg1, ...)
        • 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 Dialect

      • getCurrentSchemaCommand

        public String getCurrentSchemaCommand()
        Description copied from class: Dialect
        Get the SQL command used to retrieve the current schema name. Works in conjunction with Dialect.getSchemaNameResolver(), unless the return from there does not need this information. E.g., a custom impl might make use of the Java 1.7 addition of the Connection.getSchema() method
        Overrides:
        getCurrentSchemaCommand in class Dialect
        Returns:
        The current schema retrieval SQL

      • supportsIfExistsBeforeTableName

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

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

        Overrides:
        supportsIfExistsBeforeTableName in class Dialect
        Returns:
        true if the "if exists" can be applied before 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

      • supportsIfExistsAfterAlterTable

        public boolean supportsIfExistsAfterAlterTable()
        Description copied from class: Dialect
        For an "alter table", can the phrase "if exists" be applied?
        Overrides:
        supportsIfExistsAfterAlterTable in class Dialect
        Returns:
        true if the "if exists" can be applied after ALTER TABLE

      • supportsValuesList

        public boolean supportsValuesList()
        Description copied from class: Dialect
        Does this dialect/database support VALUES list (e.g. VALUES (1), (2), (3) )
        Overrides:
        supportsValuesList in class Dialect
        Returns:
        true if VALUES list are supported

      • supportsPartitionBy

        public boolean supportsPartitionBy()
        Description copied from class: Dialect
        Does the underlying database support partition by?
        Overrides:
        supportsPartitionBy in class Dialect

      • supportsNonQueryWithCTE

        public boolean supportsNonQueryWithCTE()
        Description copied from class: Dialect
        Does this dialect/database support non-query statements (e.g. INSERT, UPDATE, DELETE) with CTE (Common Table Expressions)?
        Overrides:
        supportsNonQueryWithCTE in class Dialect
        Returns:
        true if non-query statements are supported with CTE

      • getCascadeConstraintsString

        public String getCascadeConstraintsString()
        Description copied from class: Dialect
        The keyword that specifies that a drop table operation should be cascaded to its constraints, typically " cascade" where the leading space is required, or the empty string if there is no such keyword in this dialect.
        Overrides:
        getCascadeConstraintsString in class Dialect
        Returns:
        The cascade drop keyword, if any, with a leading space

      • 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.

      • 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.

      • getForUpdateString

        public String getForUpdateString​(String aliases,
                                 LockOptions lockOptions)
        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.
        lockOptions - the lock options to apply
        Returns:
        The appropriate FOR UPDATE OF column_list clause string.

      • 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.

      • getCaseInsensitiveLike

        public String getCaseInsensitiveLike()
        Description copied from class: Dialect
        The name of the SQL function that can do case insensitive like comparison.
        Overrides:
        getCaseInsensitiveLike in class Dialect
        Returns:
        The dialect-specific "case insensitive" like function.

      • supportsCaseInsensitiveLike

        public boolean supportsCaseInsensitiveLike()
        Description copied from class: Dialect
        Does this dialect support case insensitive LIKE restrictions?
        Overrides:
        supportsCaseInsensitiveLike in class Dialect
        Returns:
        true if the underlying database supports case insensitive like comparison, false otherwise. The default is false.

      • getNativeIdentifierGeneratorStrategy

        public String getNativeIdentifierGeneratorStrategy()
        Description copied from class: Dialect
        Resolves the native generation strategy associated to this dialect.

        Comes into play whenever the user specifies the native generator.

        Overrides:
        getNativeIdentifierGeneratorStrategy in class Dialect
        Returns:
        The native generator strategy.

      • 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.

      • getSelectClauseNullString

        public String getSelectClauseNullString​(int sqlType,
                                        TypeConfiguration typeConfiguration)
        Description copied from class: Dialect
        Given a Types type code, determine an appropriate null value to use in a select clause.

        One thing to consider here is that certain databases might require proper casting for the nulls here since the select here will be part of a UNION/UNION ALL.

        Overrides:
        getSelectClauseNullString in class Dialect
        Parameters:
        sqlType - The Types type code.
        typeConfiguration - The type configuration
        Returns:
        The appropriate select clause value fragment.

      • supportsCommentOn

        public boolean supportsCommentOn()
        Description copied from class: Dialect
        Does this dialect/database support commenting on tables, columns, etc?
        Overrides:
        supportsCommentOn in class Dialect
        Returns:
        true if commenting is supported

      • 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 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.

      • supportsTupleCounts

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

      • buildSQLExceptionConversionDelegate

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

      • registerResultSetOutParameter

        public int registerResultSetOutParameter​(CallableStatement statement,
                                         int col)
                                  throws SQLException
        Description copied from class: Dialect
        Registers a parameter (either OUT, or the new REF_CURSOR param type available in Java 8) capable of returning ResultSet *by position*. Pre-Java 8, registering such ResultSet-returning parameters varied greatly across database and drivers; hence its inclusion as part of the Dialect contract.
        Overrides:
        registerResultSetOutParameter in class Dialect
        Parameters:
        statement - The callable statement.
        col - The bind position at which to register the output param.
        Returns:
        The number of (contiguous) bind positions used.
        Throws:
        SQLException - Indicates problems registering the param.

      • 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.

      • qualifyIndexName

        public boolean qualifyIndexName()
        Description copied from class: Dialect
        Do we need to qualify index names with the schema name?
        Overrides:
        qualifyIndexName in class Dialect
        Returns:
        boolean

      • getMaxIdentifierLength

        public int getMaxIdentifierLength()
        Description copied from class: Dialect
        What is the maximum identifier length supported by the dialect?
        Overrides:
        getMaxIdentifierLength in class Dialect
        Returns:
        The maximum length.

      • appendDatetimeFormat

        public void appendDatetimeFormat​(SqlAppender appender,
                                 String format)
        Description copied from class: Dialect
        Translate the given datetime format string from the pattern language defined by Java's DateTimeFormatter to whatever pattern language is understood by the native datetime formatting function for this database (often the to_char() function).

        Since it's never possible to translate all of the pattern letter sequences understood by DateTimeFormatter, only the following subset of pattern letters is accepted by Hibernate:

        • G: era
        • y: year of era
        • Y: year of week-based year
        • M: month of year
        • w: week of week-based year (ISO week number)
        • W: week of month
        • E: day of week (name)
        • e: day of week (number)
        • d: day of month
        • D: day of year
        • a: AM/PM
        • H: hour of day (24 hour time)
        • h: hour of AM/PM (12 hour time)
        • m: minutes
        • s: seconds
        • z,Z,x: timezone offset
        In addition, punctuation characters and single-quoted literal strings are accepted.

        Appends a pattern accepted by the function that formats dates and times in this dialect to a SQL fragment that is being constructed.

        Overrides:
        appendDatetimeFormat in class Dialect

      • 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 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.

      • getWriteLockString

        public String getWriteLockString​(String aliases,
                                 int timeout)
        Description copied from class: Dialect
        Get the string to append to SELECT statements to acquire WRITE locks for this dialect given the aliases of the columns to be write locked. Location of the of the returned string is treated the same as getForUpdateString.
        Overrides:
        getWriteLockString in class Dialect
        Parameters:
        aliases - The columns to be read locked.
        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 READ locks for this dialect. Location 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.

      • getReadLockString

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

      • getForUpdateNowaitString

        public String getForUpdateNowaitString()
        Description copied from class: Dialect
        Retrieves the FOR UPDATE NOWAIT syntax specific to this dialect.
        Overrides:
        getForUpdateNowaitString in class Dialect
        Returns:
        The appropriate FOR UPDATE NOWAIT clause string.

      • getForUpdateNowaitString

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

      • getForUpdateSkipLockedString

        public String getForUpdateSkipLockedString()
        Description copied from class: Dialect
        Retrieves the FOR UPDATE SKIP LOCKED syntax specific to this dialect.
        Overrides:
        getForUpdateSkipLockedString in class Dialect
        Returns:
        The appropriate FOR UPDATE SKIP LOCKED clause string.

      • getForUpdateSkipLockedString

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

      • supportsNoWait

        public boolean supportsNoWait()
        Description copied from class: Dialect
        Does this dialect/database support NO_WAIT timeout.
        Overrides:
        supportsNoWait in class Dialect
        Returns:
        true if NO_WAIT is supported

      • supportsWait

        public boolean supportsWait()
        Description copied from class: Dialect
        Does this dialect/database support WAIT timeout.
        Overrides:
        supportsWait in class Dialect
        Returns:
        true if WAIT is supported

      • supportsSkipLocked

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

      • supportsOffsetInSubquery

        public boolean supportsOffsetInSubquery()
        Description copied from class: Dialect
        Does this dialect support offset in subqueries? Ex: select * from Table1 where col1 in (select col1 from Table2 order by col2 limit 1 offset 1)
        Overrides:
        supportsOffsetInSubquery in class Dialect
        Returns:
        boolean

      • supportsWindowFunctions

        public boolean supportsWindowFunctions()
        Description copied from class: Dialect
        Does this dialect support window functions like row_number() over (..)?
        Overrides:
        supportsWindowFunctions in class Dialect
        Returns:
        true if the underlying database supports window functions, false otherwise. The default is false.

      • 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 Dialect
        Returns:
        true if the underlying database supports lateral, false otherwise. The default is false.

      • supportsFetchClause

        public boolean supportsFetchClause​(FetchClauseType type)
        Description copied from class: Dialect
        Does this dialect support the given fetch clause type.
        Overrides:
        supportsFetchClause in class Dialect
        Parameters:
        type - The fetch clause type
        Returns:
        true if the underlying database supports the given fetch clause type, false otherwise. The default is false.

      • contributeTypes

        public void contributeTypes​(TypeContributions typeContributions,
                            ServiceRegistry serviceRegistry)
        Description copied from class: Dialect
        Allows the Dialect to contribute additional types
        Overrides:
        contributeTypes in class Dialect
        Parameters:
        typeContributions - Callback to contribute the types
        serviceRegistry - The service registry