Package org.h2.table

Class TableFilter

  • All Implemented Interfaces:
    ColumnResolver
    public class TableFilter
extends java.lang.Object
implements ColumnResolver
    A table filter represents a table that is used in a query. There is one such object whenever a table (or view) is used in a query. For example the following query has 2 table filters: SELECT * FROM TEST T1, TEST T2.

    • Field Detail

      • ORDER_IN_FROM_COMPARATOR

        public static final java.util.Comparator<TableFilter> ORDER_IN_FROM_COMPARATOR
        Comparator that uses order in FROM clause as a sort key.

      • joinOuterIndirect

        protected boolean joinOuterIndirect
        Whether this is a direct or indirect (nested) outer join

    • Constructor Detail

      • TableFilter

        public TableFilter​(SessionLocal session,
                   Table table,
                   java.lang.String alias,
                   boolean rightsChecked,
                   Select select,
                   int orderInFrom,
                   IndexHints indexHints)
        Create a new table filter object.
        Parameters:
        session - the session
        table - the table from where to read data
        alias - the alias name
        rightsChecked - true if rights are already checked
        select - the select statement
        orderInFrom - original order number (index) of this table filter in
        indexHints - the index hints to be used by the query planner

    • Method Detail

      • getOrderInFrom

        public int getOrderInFrom()
        Get the order number (index) of this table filter in the "from" clause of the query.
        Returns:
        the index (0, 1, 2,...)

      • getTable

        public Table getTable()

      • lock

        public void lock​(SessionLocal s)
        Lock the table. This will also lock joined tables.
        Parameters:
        s - the session

      • getBestPlanItem

        public PlanItem getBestPlanItem​(SessionLocal s,
                                TableFilter[] filters,
                                int filter,
                                AllColumnsForPlan allColumnsSet,
                                boolean isSelectCommand)
        Get the best plan item (index, cost) to use for the current join order.
        Parameters:
        s - the session
        filters - all joined table filters
        filter - the current table filter index
        allColumnsSet - the set of all columns
        Returns:
        the best plan item

      • setPlanItem

        public void setPlanItem​(PlanItem item)
        Set what plan item (index, cost, masks) to use.
        Parameters:
        item - the plan item

      • prepare

        public void prepare()
        Prepare reading rows. This method will remove all index conditions that can not be used, and optimize the conditions.

      • startQuery

        public void startQuery​(SessionLocal s)
        Start the query. This will reset the scan counts.
        Parameters:
        s - the session

      • reset

        public void reset()
        Reset to the current position.

      • next

        public boolean next()
        Check if there are more rows to read.
        Returns:
        true if there are

      • isNullRow

        public boolean isNullRow()

      • setNullRow

        protected void setNullRow()
        Set the state of this and all nested tables to the NULL row.

      • get

        public Row get()
        Get the current row.
        Returns:
        the current row, or null

      • set

        public void set​(Row current)
        Set the current row.
        Parameters:
        current - the current row

      • getTableAlias

        public java.lang.String getTableAlias()
        Get the table alias name. If no alias is specified, the table name is returned.
        Specified by:
        getTableAlias in interface ColumnResolver
        Returns:
        the alias name

      • addIndexCondition

        public void addIndexCondition​(IndexCondition condition)
        Add an index condition.
        Parameters:
        condition - the index condition

      • addFilterCondition

        public void addFilterCondition​(Expression condition,
                               boolean isJoin)
        Add a filter condition.
        Parameters:
        condition - the condition
        isJoin - if this is in fact a join condition

      • addJoin

        public void addJoin​(TableFilter filter,
                    boolean outer,
                    Expression on)
        Add a joined table.
        Parameters:
        filter - the joined table filter
        outer - if this is an outer join
        on - the join condition

      • setNestedJoin

        public void setNestedJoin​(TableFilter filter)
        Set a nested joined table.
        Parameters:
        filter - the joined table filter

      • addFilter

        public void addFilter​(Expression on)
        Add the join condition.
        Parameters:
        on - the condition

      • mapColumns

        public void mapColumns​(ColumnResolver resolver,
                       int level,
                       boolean outer)
        Map the columns to the given column resolver.
        Parameters:
        resolver - the resolver
        level - the subquery level (0 is the top level query, 1 is the first subquery level)
        outer - whether this method was called from the outer query

      • createIndexConditions

        public void createIndexConditions()
        Create the index conditions for this filter if needed.

      • isJoinOuter

        public boolean isJoinOuter()
        Whether this is an outer joined table.
        Returns:
        true if it is

      • isJoinOuterIndirect

        public boolean isJoinOuterIndirect()
        Whether this is indirectly an outer joined table (nested within an inner join).
        Returns:
        true if it is

      • getPlanSQL

        public java.lang.StringBuilder getPlanSQL​(java.lang.StringBuilder builder,
                                          boolean isJoin,
                                          int sqlFlags)
        Get the query execution plan text to use for this table filter and append it to the specified builder.
        Parameters:
        builder - string builder to append to
        isJoin - if this is a joined table
        sqlFlags - formatting flags
        Returns:
        the specified builder

      • getMasks

        public int[] getMasks()

      • getIndex

        public Index getIndex()

      • setIndex

        public void setIndex​(Index index,
                     boolean reverse)

      • setUsed

        public void setUsed​(boolean used)

      • isUsed

        public boolean isUsed()

      • removeJoin

        public void removeJoin()
        Remove the joined table

      • getJoinCondition

        public Expression getJoinCondition()

      • removeJoinCondition

        public void removeJoinCondition()
        Remove the join condition.

      • getFilterCondition

        public Expression getFilterCondition()

      • removeFilterCondition

        public void removeFilterCondition()
        Remove the filter condition.

      • setFullCondition

        public void setFullCondition​(Expression condition)

      • setEvaluatable

        public void setEvaluatable​(TableFilter filter,
                           boolean b)
        Update the filter and join conditions of this and all joined tables with the information that the given table filter and all nested filter can now return rows or not.
        Parameters:
        filter - the table filter
        b - the new flag

      • setEvaluatable

        public void setEvaluatable​(boolean evaluatable)

      • getSchemaName

        public java.lang.String getSchemaName()
        Description copied from interface: ColumnResolver
        Get the schema name or null.
        Specified by:
        getSchemaName in interface ColumnResolver
        Returns:
        the schema name or null

      • findColumn

        public Column findColumn​(java.lang.String name)
        Description copied from interface: ColumnResolver
        Get the column with the specified name.
        Specified by:
        findColumn in interface ColumnResolver
        Parameters:
        name - the column name, must be a derived name if this column resolver has a derived column list
        Returns:
        the column with the specified name, or null

      • getColumnName

        public java.lang.String getColumnName​(Column column)
        Description copied from interface: ColumnResolver
        Get the name of the specified column.
        Specified by:
        getColumnName in interface ColumnResolver
        Parameters:
        column - column
        Returns:
        column name

      • hasDerivedColumnList

        public boolean hasDerivedColumnList()
        Description copied from interface: ColumnResolver
        Returns whether this column resolver has a derived column list.
        Specified by:
        hasDerivedColumnList in interface ColumnResolver
        Returns:
        true if this column resolver has a derived column list, false otherwise

      • getColumn

        public Column getColumn​(java.lang.String columnName,
                        boolean ifExists)
        Get the column with the given name.
        Parameters:
        columnName - the column name
        ifExists - if true return null if column does not exist
        Returns:
        the column
        Throws:
        DbException - if the column was not found and ifExists is false

      • getSystemColumns

        public Column[] getSystemColumns()
        Get the system columns that this table understands. This is used for compatibility with other databases. The columns are only returned if the current mode supports system columns.
        Specified by:
        getSystemColumns in interface ColumnResolver
        Returns:
        the system columns

      • getRowIdColumn

        public Column getRowIdColumn()
        Description copied from interface: ColumnResolver
        Get the row id pseudo column, if there is one.
        Specified by:
        getRowIdColumn in interface ColumnResolver
        Returns:
        the row id column or null

      • getValue

        public Value getValue​(Column column)
        Description copied from interface: ColumnResolver
        Get the value for the given column.
        Specified by:
        getValue in interface ColumnResolver
        Parameters:
        column - the column
        Returns:
        the value

      • setAlias

        public void setAlias​(java.lang.String alias)

      • setDerivedColumns

        public void setDerivedColumns​(java.util.ArrayList<java.lang.String> derivedColumnNames)
        Set derived column list.
        Parameters:
        derivedColumnNames - names of derived columns

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • addCommonJoinColumns

        public void addCommonJoinColumns​(Column leftColumn,
                                 Column replacementColumn,
                                 TableFilter replacementFilter)
        Add a column to the common join column list for a left table filter.
        Parameters:
        leftColumn - the column on the left side
        replacementColumn - the column to use instead, may be the same as column on the left side
        replacementFilter - the table filter for replacement columns

      • addCommonJoinColumnToExclude

        public void addCommonJoinColumnToExclude​(Column columnToExclude)
        Add an excluded column to the common join column list.
        Parameters:
        columnToExclude - the column to exclude

      • getCommonJoinColumns

        public java.util.LinkedHashMap<Column,​Column> getCommonJoinColumns()
        Returns common join columns map.
        Returns:
        common join columns map, or null

      • getCommonJoinColumnsFilter

        public TableFilter getCommonJoinColumnsFilter()
        Returns common join columns table filter.
        Returns:
        common join columns table filter, or null

      • isCommonJoinColumnToExclude

        public boolean isCommonJoinColumnToExclude​(Column c)
        Check if the given column is an excluded common join column.
        Parameters:
        c - the column to check
        Returns:
        true if this is an excluded common join column

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • visit

        public void visit​(TableFilter.TableFilterVisitor visitor)
        Visit this and all joined or nested table filters.
        Parameters:
        visitor - the visitor

      • isEvaluatable

        public boolean isEvaluatable()

      • getIndexHints

        public IndexHints getIndexHints()

      • hasFromClause

        public boolean hasFromClause()
        Returns whether this is a table filter with implicit DUAL table for a SELECT without a FROM clause.
        Returns:
        false if this is a table filter with implicit DUAL table, true otherwise