Package org.h2.schema

Class Sequence

java.lang.Object
org.h2.engine.DbObject
org.h2.schema.SchemaObject
org.h2.schema.Sequence
All Implemented Interfaces:
HasSQL
public final class Sequence extends SchemaObject
A sequence is created using the statement CREATE SEQUENCE

  • Field Details

    • DEFAULT_CACHE_SIZE

      public static final int DEFAULT_CACHE_SIZE
      The default cache size for sequences.
      See Also:

    • baseValue

      private long baseValue

    • margin

      private long margin

    • dataType

      private TypeInfo dataType

    • increment

      private long increment

    • cacheSize

      private long cacheSize

    • startValue

      private long startValue

    • minValue

      private long minValue

    • maxValue

      private long maxValue

    • cycle

      private Sequence.Cycle cycle

    • belongsToTable

      private boolean belongsToTable

    • writeWithMargin

      private boolean writeWithMargin

  • Constructor Details

    • Sequence

      public Sequence(SessionLocal session, Schema schema, int id, String name, SequenceOptions options, boolean belongsToTable)
      Creates a new sequence.
      Parameters:
      session - the session
      schema - the schema
      id - the object id
      name - the sequence name
      options - the sequence options
      belongsToTable - whether this sequence belongs to a table (for generated columns)

  • Method Details

    • modify

      public void modify(Long baseValue, Long startValue, Long minValue, Long maxValue, Long increment, Sequence.Cycle cycle, Long cacheSize)
      Allows the base value, start value, min value, max value, increment and cache size to be updated atomically, including atomic validation. Useful because setting these attributes one after the other could otherwise result in an invalid sequence state (e.g. min value > max value, start value < min value, etc).
      Parameters:
      baseValue - the base value (null if restart is not requested)
      startValue - the new start value (null if no change)
      minValue - the new min value (null if no change)
      maxValue - the new max value (null if no change)
      increment - the new increment (null if no change)
      cycle - the new cycle value, or null if no change
      cacheSize - the new cache size (null if no change)

    • checkOptions

      private long checkOptions(long baseValue, long startValue, long minValue, long maxValue, long increment, long cacheSize, boolean mayAdjustCacheSize)
      Validates the specified prospective base value, start value, min value, max value, increment, and cache size relative to each other, since each of their respective validities are contingent on the values of the other parameters.
      Parameters:
      baseValue - the prospective base value
      startValue - the prospective start value
      minValue - the prospective min value
      maxValue - the prospective max value
      increment - the prospective increment
      cacheSize - the prospective cache size
      mayAdjustCacheSize - whether cache size may be adjusted, cache size 0 is adjusted unconditionally to 1
      Returns:
      the prospective or adjusted cache size

    • getMaxCacheSize

      private static long getMaxCacheSize(long range, long increment)

    • getDefaultMinValue

      public static long getDefaultMinValue(Long startValue, long increment, long[] bounds)
      Calculates default min value.
      Parameters:
      startValue - the start value of the sequence.
      increment - the increment of the sequence value.
      bounds - min and max bounds of data type of the sequence
      Returns:
      min value.

    • getDefaultMaxValue

      public static long getDefaultMaxValue(Long startValue, long increment, long[] bounds)
      Calculates default max value.
      Parameters:
      startValue - the start value of the sequence.
      increment - the increment of the sequence value.
      bounds - min and max bounds of data type of the sequence
      Returns:
      min value.

    • getBelongsToTable

      public boolean getBelongsToTable()

    • getDataType

      public TypeInfo getDataType()

    • getEffectivePrecision

      public int getEffectivePrecision()

    • getIncrement

      public long getIncrement()

    • getStartValue

      public long getStartValue()

    • getMinValue

      public long getMinValue()

    • getMaxValue

      public long getMaxValue()

    • getCycle

      public Sequence.Cycle getCycle()

    • getDropSQL

      public String getDropSQL()
      Description copied from class: DbObject
      Construct a DROP ... SQL statement for this object.
      Overrides:
      getDropSQL in class DbObject
      Returns:
      the SQL statement

    • getCreateSQLForCopy

      public String getCreateSQLForCopy(Table table, String quotedName)
      Description copied from class: DbObject
      Build a SQL statement to re-create the object, or to create a copy of the object with a different name or referencing a different table
      Specified by:
      getCreateSQLForCopy in class DbObject
      Parameters:
      table - the new table
      quotedName - the quoted name
      Returns:
      the SQL statement

    • getCreateSQL

      public String getCreateSQL()
      Description copied from class: DbObject
      Construct the CREATE ... SQL statement for this object.
      Specified by:
      getCreateSQL in class DbObject
      Returns:
      the SQL statement

    • getSequenceOptionsSQL

      public StringBuilder getSequenceOptionsSQL(StringBuilder builder)
      Append the options part of the SQL statement to create the sequence.
      Parameters:
      builder - the builder
      Returns:
      the builder

    • getSequenceOptionsSQL

      private StringBuilder getSequenceOptionsSQL(StringBuilder builder, long value)

    • getNext

      public Value getNext(SessionLocal session)
      Get the next value for this sequence. Should not be called directly, use SessionLocal.getNextValueFor(Sequence, org.h2.command.Prepared) instead.
      Parameters:
      session - the session
      Returns:
      the next value

    • increment

      private boolean increment(long oldBase, long newBase)

    • decrement

      private boolean decrement(long oldBase, long newBase)

    • flushWithoutMargin

      public void flushWithoutMargin()
      Flush the current value to disk.

    • flush

      public void flush(SessionLocal session)
      Flush the current value, including the margin, to disk.
      Parameters:
      session - the session

    • flushInternal

      private void flushInternal(SessionLocal session)

    • close

      public void close()
      Flush the current value to disk and close this object.

    • getType

      public int getType()
      Description copied from class: DbObject
      Get the object type.
      Specified by:
      getType in class DbObject
      Returns:
      the object type

    • removeChildrenAndResources

      public void removeChildrenAndResources(SessionLocal session)
      Description copied from class: DbObject
      Delete all dependent children objects and resources of this object.
      Specified by:
      removeChildrenAndResources in class DbObject
      Parameters:
      session - the session

    • getBaseValue

      public long getBaseValue()

    • getCurrentValue

      public long getCurrentValue()

    • setBelongsToTable

      public void setBelongsToTable(boolean b)

    • getCacheSize

      public long getCacheSize()