Package mondrian.rolap

Class SqlTupleReader

java.lang.Object
mondrian.rolap.SqlTupleReader
All Implemented Interfaces:
TupleReader
Direct Known Subclasses:
HighCardSqlTupleReader
public class SqlTupleReader extends Object implements TupleReader
Reads the members of a single level (level.members) or of multiple levels (crossjoin).

Allows the result to be restricted by a TupleConstraint. So the SqlTupleReader can also read Member.Descendants (which is level.members restricted to a common parent) and member.children (which is a special case of member.descendants). Other constraints, especially for the current slicer or evaluation context, are possible.

Caching

When a SqlTupleReader reads level.members, it groups the result into parent/children pairs and puts them into the cache. In order that these can be found later when the children of a parent are requested, a matching constraint must be provided for every parent.

Since:
Nov 11, 2005
Author:
av

  • Field Details

  • Constructor Details

  • Method Details

    • isAllowHints

      public boolean isAllowHints()

    • setAllowHints

      public void setAllowHints(boolean allowHints)

    • incrementEmptySets

      public void incrementEmptySets()
      Description copied from interface: TupleReader
      Indicates that there was an empty argument somewhere in the tuple.
      Specified by:
      incrementEmptySets in interface TupleReader

    • addLevelMembers

      public void addLevelMembers(RolapLevel level, TupleReader.MemberBuilder memberBuilder, List<RolapMember> srcMembers)
      Description copied from interface: TupleReader
      Adds a hierarchy to retrieve members from.
      Specified by:
      addLevelMembers in interface TupleReader
      Parameters:
      level - level that the members correspond to
      memberBuilder - used to build new members for this level
      srcMembers - if set, array of enumerated members that make up this level

    • getCacheKey

      public Object getCacheKey()
      Description copied from interface: TupleReader
      Returns an object that uniquely identifies the Result that this TupleReader would return. Clients may use this as a key for caching the result.
      Specified by:
      getCacheKey in interface TupleReader
      Returns:
      Cache key

    • getEnumTargetCount

      public int getEnumTargetCount()
      Returns:
      number of targets that contain enumerated sets with calculated members

    • prepareTuples

      protected void prepareTuples(DataSource dataSource, TupleList partialResult, List<List<RolapMember>> newPartialResult, List<TargetBase> targetGroup)

    • readMembers

      public TupleList readMembers(DataSource dataSource, TupleList partialResult, List<List<RolapMember>> newPartialResult)
      Description copied from interface: TupleReader
      Performs the read.
      Specified by:
      readMembers in interface TupleReader
      Parameters:
      dataSource - source for reading tuples
      partialResult - partially cached result that should be used instead of executing sql query
      newPartialResult - if non-null, return the result of the read; note that this is a subset of the full return list
      Returns:
      a list of RolapMember

    • bumpNullMember

      protected List<Member> bumpNullMember(List<Member> members)

    • readTuples

      public TupleList readTuples(DataSource jdbcConnection, TupleList partialResult, List<List<RolapMember>> newPartialResult)
      Description copied from interface: TupleReader
      Performs the read.
      Specified by:
      readTuples in interface TupleReader
      Parameters:
      jdbcConnection - Data source
      partialResult - List of rows from previous pass
      newPartialResult - Populated with a new list of rows
      Returns:
      a list of tuples

    • addLevelMemberSql

      protected void addLevelMemberSql(SqlQuery sqlQuery, RolapLevel level, RolapCube baseCube, mondrian.rolap.SqlTupleReader.WhichSelect whichSelect, AggStar aggStar)
      Generates the SQL statement to access members of level. For example, 
      SELECT "country", "state_province", "city"
 FROM "customer"
 GROUP BY "country", "state_province", "city", "init", "bar"
 ORDER BY "country", "state_province", "city"
      accesses the "City" level of the "Customers" hierarchy. Note that:
      • "country", "state_province" are the parent keys;
      • "city" is the level key;
      • "init", "bar" are member properties.
      Parameters:
      sqlQuery - the query object being constructed
      level - level to be added to the sql query
      baseCube - this is the cube object for regular cubes, and the underlying base cube for virtual cubes
      whichSelect - describes whether this select belongs to a larger
      aggStar - aggregate star if available

    • getEvaluator

      protected Evaluator getEvaluator(TupleConstraint constraint)
      Obtains the evaluator used to find an aggregate table to support the Tuple constraint.
      Parameters:
      constraint - Constraint
      Returns:
      evaluator for constraint