Package org.h2.table

Class Column

java.lang.Object
org.h2.table.Column
All Implemented Interfaces:
ColumnTemplate, HasSQL, Typed
public final class Column extends Object implements HasSQL, Typed, ColumnTemplate
This class represents a column in a table.

  • Field Details

    • ROWID

      public static final String ROWID
      The name of the rowid pseudo column.
      See Also:

    • NOT_NULLABLE

      public static final int NOT_NULLABLE
      This column is not nullable.
      See Also:

    • NULLABLE

      public static final int NULLABLE
      This column is nullable.
      See Also:

    • NULLABLE_UNKNOWN

      public static final int NULLABLE_UNKNOWN
      It is not know whether this column is nullable.
      See Also:

  • Constructor Details

  • Method Details

    • writeColumns

      public static StringBuilder writeColumns(StringBuilder builder, Column[] columns, int sqlFlags)
      Appends the specified columns to the specified builder.
      Parameters:
      builder - string builder
      columns - columns
      sqlFlags - formatting flags
      Returns:
      the specified string builder

    • writeColumns

      public static StringBuilder writeColumns(StringBuilder builder, Column[] columns, String separator, String suffix, int sqlFlags)
      Appends the specified columns to the specified builder.
      Parameters:
      builder - string builder
      columns - columns
      separator - separator
      suffix - additional SQL to append after each column
      sqlFlags - formatting flags
      Returns:
      the specified string builder

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • getClone

      public Column getClone()

    • convert

      public Value convert(CastDataProvider provider, Value v)
      Convert a value to this column's type without precision and scale checks.
      Parameters:
      provider - the cast information provider
      v - the value
      Returns:
      the value

    • convert

      public static ValueRow convert(CastDataProvider provider, Column[] columns, ValueRow valueRow)
      Converts the values in a ValueRow based on the passed column info. Creates a new instance if any of the contained item must be converted. Otherwise, returns the same valueRow.
      Parameters:
      provider - the cast information provider
      columns - the column info list used for the conversation
      valueRow - the holder of the values
      Returns:
      a ValueRow which contains the converted values
      See Also:

    • isIdentity

      public boolean isIdentity()
      Returns whether this column is an identity column.
      Returns:
      whether this column is an identity column

    • isGenerated

      public boolean isGenerated()
      Returns whether this column is a generated column.
      Returns:
      whether this column is a generated column

    • isGeneratedAlways

      public boolean isGeneratedAlways()
      Returns whether this column is a generated column or always generated identity column.
      Returns:
      whether this column is a generated column or always generated identity column

    • setGeneratedExpression

      public void setGeneratedExpression(Expression expression)
      Set the default value in the form of a generated expression of other columns.
      Parameters:
      expression - the computed expression

    • setTable

      public void setTable(Table table, int columnId)
      Set the table and column id.
      Parameters:
      table - the table
      columnId - the column index

    • getTable

      public Table getTable()

    • setDefaultExpression

      public void setDefaultExpression(SessionLocal session, Expression defaultExpression)
      Description copied from interface: ColumnTemplate
      Set the default expression.
      Specified by:
      setDefaultExpression in interface ColumnTemplate
      Parameters:
      session - the session
      defaultExpression - the default expression

    • setOnUpdateExpression

      public void setOnUpdateExpression(SessionLocal session, Expression onUpdateExpression)
      Description copied from interface: ColumnTemplate
      Set the on update expression.
      Specified by:
      setOnUpdateExpression in interface ColumnTemplate
      Parameters:
      session - the session
      onUpdateExpression - the on update expression

    • getColumnId

      public int getColumnId()

    • getSQL

      public String getSQL(int sqlFlags)
      Description copied from interface: HasSQL
      Get the SQL statement of this expression. This may not always be the original SQL statement, specially after optimization.
      Specified by:
      getSQL in interface HasSQL
      Parameters:
      sqlFlags - formatting flags
      Returns:
      the SQL statement

    • getSQL

      public StringBuilder getSQL(StringBuilder builder, int sqlFlags)
      Description copied from interface: HasSQL
      Appends the SQL statement of this object to the specified builder.
      Specified by:
      getSQL in interface HasSQL
      Parameters:
      builder - string builder
      sqlFlags - formatting flags
      Returns:
      the specified string builder

    • getSQLWithTable

      public StringBuilder getSQLWithTable(StringBuilder builder, int sqlFlags)
      Appends the table name and column name to the specified builder.
      Parameters:
      builder - the string builder
      sqlFlags - formatting flags
      Returns:
      the specified string builder

    • getName

      public String getName()

    • getType

      public TypeInfo getType()
      Description copied from interface: Typed
      Returns the data type.
      Specified by:
      getType in interface Typed
      Returns:
      the data type

    • setType

      public void setType(TypeInfo type)

    • setNullable

      public void setNullable(boolean b)

    • getVisible

      public boolean getVisible()

    • setVisible

      public void setVisible(boolean b)

    • getDomain

      public Domain getDomain()
      Specified by:
      getDomain in interface ColumnTemplate

    • setDomain

      public void setDomain(Domain domain)
      Specified by:
      setDomain in interface ColumnTemplate

    • isRowId

      public boolean isRowId()
      Returns whether this column is a row identity column.
      Returns:
      true for _ROWID_ column, false otherwise

    • setRowId

      public void setRowId(boolean rowId)
      Set row identity flag.
      Parameters:
      rowId - true _ROWID_ column, false otherwise

    • initializeSequence

      public void initializeSequence(SessionLocal session, Schema schema, int id, boolean temporary)
      Initialize the sequence for this column.
      Parameters:
      session - the session
      schema - the schema where the sequence should be generated
      id - the object id
      temporary - true if the sequence is temporary and does not need to be stored

    • prepareExpressions

      public void prepareExpressions(SessionLocal session)
      Description copied from interface: ColumnTemplate
      Prepare all expressions of this column or domain.
      Specified by:
      prepareExpressions in interface ColumnTemplate
      Parameters:
      session - the session

    • getCreateSQLWithoutName

      public String getCreateSQLWithoutName()

    • getCreateSQL

      public String getCreateSQL()

    • getCreateSQL

      public String getCreateSQL(boolean forMeta)
      Get this columns part of CREATE TABLE SQL statement.
      Parameters:
      forMeta - whether this is for the metadata table
      Returns:
      the SQL statement

    • isNullable

      public boolean isNullable()

    • getDefaultExpression

      public Expression getDefaultExpression()
      Specified by:
      getDefaultExpression in interface ColumnTemplate

    • getEffectiveDefaultExpression

      public Expression getEffectiveDefaultExpression()
      Specified by:
      getEffectiveDefaultExpression in interface ColumnTemplate

    • getOnUpdateExpression

      public Expression getOnUpdateExpression()
      Specified by:
      getOnUpdateExpression in interface ColumnTemplate

    • getEffectiveOnUpdateExpression

      public Expression getEffectiveOnUpdateExpression()
      Specified by:
      getEffectiveOnUpdateExpression in interface ColumnTemplate

    • hasIdentityOptions

      public boolean hasIdentityOptions()
      Whether the column has any identity options.
      Returns:
      true if yes

    • setIdentityOptions

      public void setIdentityOptions(SequenceOptions identityOptions, boolean generatedAlways)
      Set the identity options of this column.
      Parameters:
      identityOptions - identity column options
      generatedAlways - whether value should be always generated

    • getIdentityOptions

      public SequenceOptions getIdentityOptions()
      Returns identity column options, or null if sequence was already created or this column is not an identity column.
      Returns:
      identity column options, or null

    • setDefaultOnNull

      public void setDefaultOnNull(boolean defaultOnNull)

    • isDefaultOnNull

      public boolean isDefaultOnNull()

    • rename

      public void rename(String newName)
      Rename the column. This method will only set the column name to the new value.
      Parameters:
      newName - the new column name

    • setSequence

      public void setSequence(Sequence sequence, boolean generatedAlways)
      Set the sequence to generate the value.
      Parameters:
      sequence - the sequence
      generatedAlways - whether the value of the sequence is always used

    • getSequence

      public Sequence getSequence()

    • getSelectivity

      public int getSelectivity()
      Get the selectivity of the column. Selectivity 100 means values are unique, 10 means every distinct value appears 10 times on average.
      Returns:
      the selectivity

    • setSelectivity

      public void setSelectivity(int selectivity)
      Set the new selectivity of a column.
      Parameters:
      selectivity - the new value

    • getDefaultSQL

      public String getDefaultSQL()
      Specified by:
      getDefaultSQL in interface ColumnTemplate

    • getOnUpdateSQL

      public String getOnUpdateSQL()
      Specified by:
      getOnUpdateSQL in interface ColumnTemplate

    • setComment

      public void setComment(String comment)

    • getComment

      public String getComment()

    • setPrimaryKey

      public void setPrimaryKey(boolean primaryKey)

    • isPrimaryKey

      public boolean isPrimaryKey()

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • isWideningConversion

      public boolean isWideningConversion(Column newColumn)
      Check whether the new column is of the same type and not more restricted than this column.
      Parameters:
      newColumn - the new (target) column
      Returns:
      true if the new column is compatible

    • copy

      public void copy(Column source)
      Copy the data of the source column into the current column.
      Parameters:
      source - the source column