org.dspace.browse
Interface BrowseDAO

All Known Implementing Classes:
BrowseDAOOracle, BrowseDAOPostgres

public interface BrowseDAO

Interface for any class wishing to interact with the Browse storage layer for Read Only operations. If you wish to modify the contents of the browse indices or create and destroy index tables you should look at implementations for BrowseCreateDAO. If you implement this class, and you wish it to be loaded via the BrowseDAOFactory you must supply a constructor of the form: public BrowseDAOImpl(Context context) {} Where Context is the DSpace Context object Where tables are referred to in this class, they can be obtained from the BrowseIndex class, which will answer queries given the context of the request on which table is the relevant target.

Author:
Richard Jones

Method Summary
 int doCountQuery()
          This executes a query which will count the number of results for the parameters you set.
 int doDistinctOffsetQuery(String column, String value, boolean isAscending)
          This executes a query which returns the offset where the value (or nearest greater equivalent) can be found in the specified table ordered by the column.
 String doMaxQuery(String column, String table, int itemID)
          This executes a query which returns the value of the "highest" (max) value in the given table's column for the given item id.
 int doOffsetQuery(String column, String value, boolean isAscending)
          This executes a query which returns the offset where the value (or nearest greater equivalent) can be found in the specified table ordered by the column.
 List doQuery()
          This executes a query which returns a List object containing BrowseItem objects represening the results of a full item browse.
 List doValueQuery()
          This executes a query which returns a List object containing String values which represent the results of a single value browse (for example, the list of all subject headings).
 String getAuthorityValue()
           
 int getContainerID()
          Get the database ID of the container object.
 String getContainerIDField()
          get the name of the field in which to look for the container id.
 String getContainerTable()
          Get the name of the container table that is being used to map items to distinct values when in a container constrained browse
 String[] getCountValues()
          Get the array of fields that we will be counting on.
 String getFilterValue()
          Get the value which we are constraining all our browse results to contain.
 String getFilterValueField()
          Get the name of the field in which the value to constrain results is contained
 String getJumpToField()
          Get the field in which we will match a focus value from which to start the browse.
 String getJumpToValue()
          Get the value at which the browse will start.
 int getLimit()
          get the integer number which is the limit of the results that will be returned by any query.
 int getOffset()
          Get the offset from the first result from which to return results.
 String getOrderField()
          Get the database field which will be used to do the sorting of result sets on.
 String[] getSelectValues()
          Get the array of values that we will be selecting on.
 String getTable()
          get the name of the table that we are querying
 boolean isAscending()
          Is the sort order ascending or descending? Default value is true
 boolean isDistinct()
          Is this a distinct value browse?
 void setAscending(boolean ascending)
          Set whether the results should be sorted in ascending order (on the given sort column) or descending order.
 void setAuthorityValue(String value)
           
 void setContainerID(int containerID)
          Set the database id of the container object.
 void setContainerIDField(String containerIDField)
          set the name of the field in which to look for the container id.
 void setContainerTable(String containerTable)
          If we have specified a container id and container field, we must also specify a container table.
 void setCountValues(String[] fields)
          Set the array of columns that we will be counting over.
 void setDistinct(boolean bool)
          Set whether this is a distinct value browse or not
 void setEqualsComparator(boolean equalsComparator)
          Set whether the query should use an equals comparator when doing less than or greater than comparisons.
 void setFilterMappingTables(String tableDis, String tableMap)
          Set the name of the mapping tables to use for filtering
 void setFilterValue(String value)
          Set the value to which all our browse results should be constrained.
 void setFilterValueField(String valueField)
          Set he name of the field in which the value to constrain results is contained
 void setFilterValuePartial(boolean part)
          Sets whether we will treat the filter value as partial (like match), or exact
 void setJumpToField(String focusField)
          Set the focus field upon which we will match a value from which to start the browse.
 void setJumpToValue(String focusValue)
          Set the value upon which to start the browse from.
 void setLimit(int limit)
          Set the limit for how many results should be returned.
 void setOffset(int offset)
          Get the offset from the first result from which to return results.
 void setOrderField(String orderField)
          Set the database field which will be used to sort result sets on
 void setSelectValues(String[] selectValues)
          Set the array of values to select on.
 void setTable(String table)
          Set the name of the table to query
 boolean useEqualsComparator()
          Does the query use the equals comparator when doing less than or greater than comparisons.
 

Method Detail

doCountQuery

int doCountQuery()
                 throws BrowseException
This executes a query which will count the number of results for the parameters you set.

Returns:
the integer value of the number of results found
Throws:
BrowseException

doValueQuery

List doValueQuery()
                  throws BrowseException
This executes a query which returns a List object containing String values which represent the results of a single value browse (for example, the list of all subject headings). This is most commonly used with a Distinct browse type.

Returns:
List of Strings representing the single value query results
Throws:
BrowseException

doQuery

List doQuery()
             throws BrowseException
This executes a query which returns a List object containing BrowseItem objects represening the results of a full item browse.

Returns:
List of BrowseItem objects
Throws:
BrowseException

doMaxQuery

String doMaxQuery(String column,
                  String table,
                  int itemID)
                  throws BrowseException
This executes a query which returns the value of the "highest" (max) value in the given table's column for the given item id.

Parameters:
column - the column to interrogate
table - the table to query
itemID - the item id
Returns:
String representing the max value in the given column
Throws:
BrowseException

doOffsetQuery

int doOffsetQuery(String column,
                  String value,
                  boolean isAscending)
                  throws BrowseException
This executes a query which returns the offset where the value (or nearest greater equivalent) can be found in the specified table ordered by the column.

Parameters:
column - the column to interrogate
value - the item id
isAscending - browsing in ascending or descending order
Returns:
the offset into the table
Throws:
BrowseException

doDistinctOffsetQuery

int doDistinctOffsetQuery(String column,
                          String value,
                          boolean isAscending)
                          throws BrowseException
This executes a query which returns the offset where the value (or nearest greater equivalent) can be found in the specified table ordered by the column.

Parameters:
column - the column to interrogate
value - the item id
isAscending - browsing in ascending or descending order
Returns:
the offset into the table
Throws:
BrowseException

useEqualsComparator

boolean useEqualsComparator()
Does the query use the equals comparator when doing less than or greater than comparisons. @see setEqualsComparator Default value is true

Returns:
true if using it, false if not

setEqualsComparator

void setEqualsComparator(boolean equalsComparator)
Set whether the query should use an equals comparator when doing less than or greater than comparisons. That is, if true then comparisons will be made using the equivalent of "<=" and ">=", while if false it will use the equivalent of "<" and ">"

Parameters:
equalsComparator - true to use, false to not.

isAscending

boolean isAscending()
Is the sort order ascending or descending? Default value is true

Returns:
true for ascending, false for descending

setAscending

void setAscending(boolean ascending)
Set whether the results should be sorted in ascending order (on the given sort column) or descending order.

Parameters:
ascending - true to ascend, false to descend

getContainerID

int getContainerID()
Get the database ID of the container object. The container object will be a Community or a Collection.

Returns:
the database id of the container, or -1 if none is set

setContainerID

void setContainerID(int containerID)
Set the database id of the container object. This should be the id of a Community or Collection. This will constrain the results of the browse to only items or values within items that appear in the given container.

Parameters:
containerID -

getContainerIDField

String getContainerIDField()
get the name of the field in which to look for the container id. This is principally for use internal to the DAO.

Returns:
the name of the container id field. For example "collection_id" or "community_id"

setContainerIDField

void setContainerIDField(String containerIDField)
set the name of the field in which to look for the container id.

Parameters:
containerIDField - the name of the container id field. For example "collection_id" or "community_id"

getJumpToField

String getJumpToField()
Get the field in which we will match a focus value from which to start the browse. This will either be the "sort_value" field or one of the additional sort fields defined by configuration

Returns:
the name of the focus field

setJumpToField

void setJumpToField(String focusField)
Set the focus field upon which we will match a value from which to start the browse. This will either be the "sort_value" field or one of the additional sort fields defined by configuration param focusField the name of the focus field


getJumpToValue

String getJumpToValue()
Get the value at which the browse will start. The value supplied here will be the top result on the page of results.

Returns:
the value to start browsing on

setJumpToValue

void setJumpToValue(String focusValue)
Set the value upon which to start the browse from. The value supplied here will be the top result on the page of results

Parameters:
focusValue - the value in the focus field on which to start browsing

getLimit

int getLimit()
get the integer number which is the limit of the results that will be returned by any query. The default is -1, which means unlimited results.

Returns:
the maximum possible number of results allowed to be returned

setLimit

void setLimit(int limit)
Set the limit for how many results should be returned. This is generally for use in paging or limiting the number of items be be displayed. The default is -1, meaning unlimited results. Note that if the number of results of the query is less than this number, the size of the result set will be smaller than this limit.

Parameters:
limit - the maximum number of results to return.

getOffset

int getOffset()
Get the offset from the first result from which to return results. This functionality is present for backwards compatibility, but is ill advised. All normal browse operations can be completed without it. The default is -1, which means do not offset.

Returns:
the offset

setOffset

void setOffset(int offset)
Get the offset from the first result from which to return results. This functionality is present for backwards compatibility, but is ill advised. All normal browse operations can be completed without it. The default is -1, which means do not offset.

Parameters:
offset -

getOrderField

String getOrderField()
Get the database field which will be used to do the sorting of result sets on.

Returns:
the field by which results will be sorted

setOrderField

void setOrderField(String orderField)
Set the database field which will be used to sort result sets on

Parameters:
orderField - the field by which results will be sorted

getSelectValues

String[] getSelectValues()
Get the array of values that we will be selecting on. The default is to select all of the values from a given table

Returns:
an array of values to select on

setSelectValues

void setSelectValues(String[] selectValues)
Set the array of values to select on. This should be a list of the columns available in the target table, or the SQL wildcards. The default is single element array with the standard wildcard (*)

Parameters:
selectValues - the values to select on

getCountValues

String[] getCountValues()
Get the array of fields that we will be counting on.

Returns:
an array of fields to be counted over

setCountValues

void setCountValues(String[] fields)
Set the array of columns that we will be counting over. In general, the wildcard (*) will suffice

Parameters:
fields - an array of fields to be counted over

getTable

String getTable()
get the name of the table that we are querying

Returns:
the name of the table

setTable

void setTable(String table)
Set the name of the table to query

Parameters:
table - the name of the table

setFilterMappingTables

void setFilterMappingTables(String tableDis,
                            String tableMap)
Set the name of the mapping tables to use for filtering

Parameters:
tableDis - the name of the table holding the distinct values
tableMap - the name of the table holding the mappings

getFilterValue

String getFilterValue()
Get the value which we are constraining all our browse results to contain.

Returns:
the value to which to constrain results

setFilterValue

void setFilterValue(String value)
Set the value to which all our browse results should be constrained. For example, if you are listing all of the publications by a single author your value would be the author name.

Parameters:
value - the value to which to constrain results

setFilterValuePartial

void setFilterValuePartial(boolean part)
Sets whether we will treat the filter value as partial (like match), or exact

Parameters:
part - true if partial, false if exact

getFilterValueField

String getFilterValueField()
Get the name of the field in which the value to constrain results is contained

Returns:
the name of the field

setFilterValueField

void setFilterValueField(String valueField)
Set he name of the field in which the value to constrain results is contained

Parameters:
valueField - the name of the field

setDistinct

void setDistinct(boolean bool)
Set whether this is a distinct value browse or not

Parameters:
bool - true if distinct value, false if not

isDistinct

boolean isDistinct()
Is this a distinct value browse?

Returns:
true if distinct, false if not

setContainerTable

void setContainerTable(String containerTable)
If we have specified a container id and container field, we must also specify a container table. This is the name of the table that maps the item onto the distinct value. Since we are in a container, this value will actually be the view which allows us to select only items which are within a given container

Parameters:
containerTable - the name of the container table mapping

getContainerTable

String getContainerTable()
Get the name of the container table that is being used to map items to distinct values when in a container constrained browse

Returns:
the name of the table

setAuthorityValue

void setAuthorityValue(String value)

getAuthorityValue

String getAuthorityValue()


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