Class MariaDBDialect

    • Method Detail

      • 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 MySQLDialect
      • supportsWindowFunctions

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

        public boolean supportsColumnCheck()
        Description copied from class: Dialect
        Does this dialect support column-level check constraints?
        Overrides:
        supportsColumnCheck in class MySQLDialect
        Returns:
        True if column-level CHECK constraints are supported; false otherwise.
      • 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
      • 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.
      • supportsSkipLocked

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

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