AbstractQuery (Carbonado 1.2.3 API)

java.lang.Object
+
- com.amazon.carbonado.qe.AbstractQuery<S>
+

+
+
All Implemented Interfaces:
+
Query<S>, Appender
+
+
+
Direct Known Subclasses:
+
EmptyQuery, StandardQuery
+
+
+
+
```
public abstract class AbstractQuery<S extends Storable>
+extends java.lang.Object
+implements Query<S>, Appender
```
+
AbstractQuery implements a small set of common Query methods. Subclasses + should consider overriding some of these methods, if it provides better + performance.
+
Author:
+
Brian S O'Neill
+

+ +

+ + +
Nested Class Summary
+
- + + +
  Nested classes/interfaces inherited from interface com.amazon.carbonado.Query
  +Query.Controller, Query.Timeout
+

+ +

+ + +
Constructor Summary
+ + + + + + + + + + +
Constructors
Modifier Constructor and Description
protected AbstractQuery()
+

Constructors
Modifier	Constructor and Description
`protected`	`AbstractQuery()`

+ +

+ + +

Method Summary

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Methods
Modifier and Type	Method and Description
`Query<S>`	`and(java.lang.String filter)` + Returns a new query which has another `filter` logically "and"ed to this, potentially reducing the amount of + results. +
`protected boolean`	`checkSliceArguments(long from, + java.lang.Long to)` + Called by sliced fetch to ensure that arguments are valid. +
`void`	`deleteOne()` + Deletes one matching object. +
`void`	`deleteOne(Query.Controller controller)` + Deletes one matching object. +
`abstract boolean`	`equals(java.lang.Object obj)`
`<T extends S> Cursor<S>`	`fetchAfter(T start)` + Fetches results for this query after a given starting point, which is + useful for re-opening a cursor. +
`<T extends S> Cursor<S>`	`fetchAfter(T start, + Query.Controller controller)` + Fetches results for this query after a given starting point, which is + useful for re-opening a cursor. +
`abstract int`	`hashCode()`
`S`	`loadOne()` + Attempts to load exactly one matching object. +
`S`	`loadOne(Query.Controller controller)` + Attempts to load exactly one matching object. +
`Query<S>`	`or(java.lang.String filter)` + Returns a new query which has another `filter` logically "or"ed to this, potentially increasing the amount of + results. +
`boolean`	`printNative()` + Print the native query to standard out, which is useful for performance + analysis. +
`boolean`	`printNative(java.lang.Appendable app)` + Prints the native query to any appendable, which is useful for + performance analysis. +
`boolean`	`printPlan()` + Prints the query excecution plan to standard out, which is useful for + performance analysis. +
`boolean`	`printPlan(java.lang.Appendable app)` + Prints the query excecution plan to any appendable, which is useful for + performance analysis. +
`java.lang.String`	`toString()` + Implementation calls appendTo. +
`S`	`tryLoadOne()` + Tries to load one record, but returns null if nothing was found. +
`S`	`tryLoadOne(Query.Controller controller)` + Tries to load one record, but returns null if nothing was found. +

+ + +
Methods inherited from class java.lang.Object
+clone, finalize, getClass, notify, notifyAll, wait, wait, wait

+ + +
Methods inherited from interface com.amazon.carbonado.Query
+after, and, count, count, deleteAll, deleteAll, exists, exists, fetch, fetch, fetchSlice, fetchSlice, getBlankParameterCount, getFilter, getFilterValues, getStorableType, not, or, orderBy, orderBy, printNative, printPlan, tryDeleteOne, tryDeleteOne, with, with, with, with, with, with, with, with, with, withValues

+ + +
Methods inherited from interface com.amazon.carbonado.util.Appender
+appendTo

+ +
- + + +
  Constructor Detail
  + + + +
  - +
    AbstractQuery
    +
```
protected AbstractQuery()
```
    +
  +
+ +
- + + +
  Method Detail
  + + + +
  - +
    and
    +
```
public Query<S> and(java.lang.String filter)
+                              throws FetchException
```
    +
    Description copied from interface: Query
    +
    Returns a new query which has another filter logically "and"ed to this, potentially reducing the amount of + results.
    +
    +
    Specified by:
    +
    and in interface Query<S extends Storable>
    +
    Parameters:
    filter - query filter expression
    +
    Throws:
    +
    FetchException - if storage layer throws an exception
    +
  + + + +
  - +
    or
    +
```
public Query<S> or(java.lang.String filter)
+                             throws FetchException
```
    +
    Description copied from interface: Query
    +
    Returns a new query which has another filter logically "or"ed to this, potentially increasing the amount of + results.
    +
    +
    Specified by:
    +
    or in interface Query<S extends Storable>
    +
    Parameters:
    filter - query filter expression
    +
    Throws:
    +
    FetchException - if storage layer throws an exception
    +
  + + + + + +
  - +
    fetchAfter
    +
```
public <T extends S> Cursor<S> fetchAfter(T start)
+                                      throws FetchException
```
    +
    Description copied from interface: Query
    +
    Fetches results for this query after a given starting point, which is + useful for re-opening a cursor. This is only effective when query has + been given an explicit ordering. If not a total + ordering, then cursor may start at an earlier position. + +
    Note: This method can be very expensive to call repeatedly, if the + query needs to perform a sort operation. Ideally, the query ordering + should match the natural ordering of an index or key. + +
    Calling fetchAfter(s) is equivalent to calling after(s).fetch().
    +
    +
    Specified by:
    +
    fetchAfter in interface Query<S extends Storable>
    +
    Parameters:
    start - storable to attempt to start after; if null, fetch all results
    +
    Returns:
    fetch results
    +
    Throws:
    +
    FetchException - if storage layer throws an exception
    See Also:
    Repository.enterTransaction(IsolationLevel), +Query.after(T)
    +
  + + + + + +
  - +
    fetchAfter
    +
```
public <T extends S> Cursor<S> fetchAfter(T start,
+                                 Query.Controller controller)
+                                      throws FetchException
```
    +
    Description copied from interface: Query
    +
    Fetches results for this query after a given starting point, which is + useful for re-opening a cursor. This is only effective when query has + been given an explicit ordering. If not a total + ordering, then cursor may start at an earlier position. + +
    Note: This method can be very expensive to call repeatedly, if the + query needs to perform a sort operation. Ideally, the query ordering + should match the natural ordering of an index or key. + +
    Calling fetchAfter(s) is equivalent to calling after(s).fetch().
    +
    +
    Specified by:
    +
    fetchAfter in interface Query<S extends Storable>
    +
    Parameters:
    start - storable to attempt to start after; if null, fetch all results
    controller - optional controller which can abort query operation
    +
    Returns:
    fetch results
    +
    Throws:
    +
    FetchException - if storage layer throws an exception
    See Also:
    Repository.enterTransaction(IsolationLevel), +Query.after(T)
    +
  + + + +
  - +
    loadOne
    +
```
public S loadOne()
+                           throws FetchException
```
    +
    Description copied from interface: Query
    +
    Attempts to load exactly one matching object. If the number of matching + records is zero or exceeds one, then an exception is thrown instead.
    +
    +
    Specified by:
    +
    loadOne in interface Query<S extends Storable>
    +
    Returns:
    a single fetched object
    +
    Throws:
    +
    FetchNoneException - if no matching record found
    +
    FetchMultipleException - if more than one matching record found
    +
    FetchException - if storage layer throws an exception
    +
  + + + +
  - +
    loadOne
    +
```
public S loadOne(Query.Controller controller)
+                           throws FetchException
```
    +
    Description copied from interface: Query
    +
    Attempts to load exactly one matching object. If the number of matching + records is zero or exceeds one, then an exception is thrown instead.
    +
    +
    Specified by:
    +
    loadOne in interface Query<S extends Storable>
    +
    Parameters:
    controller - optional controller which can abort query operation
    +
    Returns:
    a single fetched object
    +
    Throws:
    +
    FetchNoneException - if no matching record found
    +
    FetchMultipleException - if more than one matching record found
    +
    FetchException - if storage layer throws an exception
    +
  + + + +
  - +
    tryLoadOne
    +
```
public S tryLoadOne()
+                              throws FetchException
```
    +
    Description copied from interface: Query
    +
    Tries to load one record, but returns null if nothing was found. Throws + exception if record count is more than one.
    +
    +
    Specified by:
    +
    tryLoadOne in interface Query<S extends Storable>
    +
    Returns:
    null or a single fetched object
    +
    Throws:
    +
    FetchMultipleException - if more than one matching record found
    +
    FetchException - if storage layer throws an exception
    +
  + + + +
  - +
    tryLoadOne
    +
```
public S tryLoadOne(Query.Controller controller)
+                              throws FetchException
```
    +
    Description copied from interface: Query
    +
    Tries to load one record, but returns null if nothing was found. Throws + exception if record count is more than one.
    +
    +
    Specified by:
    +
    tryLoadOne in interface Query<S extends Storable>
    +
    Parameters:
    controller - optional controller which can abort query operation
    +
    Returns:
    null or a single fetched object
    +
    Throws:
    +
    FetchMultipleException - if more than one matching record found
    +
    FetchException - if storage layer throws an exception
    +
  + + + +
  - +
    deleteOne
    +
```
public void deleteOne()
+               throws PersistException
```
    +
    Description copied from interface: Query
    +
    Deletes one matching object. If the number of matching records is zero or + exceeds one, then no delete occurs, and an exception is thrown instead.
    +
    +
    Specified by:
    +
    deleteOne in interface Query<S extends Storable>
    +
    Throws:
    +
    PersistNoneException - if no matching record found
    +
    PersistMultipleException - if more than one record matches
    +
    PersistException - if storage layer throws an exception
    +
  + + + +
  - +
    deleteOne
    +
```
public void deleteOne(Query.Controller controller)
+               throws PersistException
```
    +
    Description copied from interface: Query
    +
    Deletes one matching object. If the number of matching records is zero or + exceeds one, then no delete occurs, and an exception is thrown instead.
    +
    +
    Specified by:
    +
    deleteOne in interface Query<S extends Storable>
    +
    Parameters:
    controller - optional controller which can abort query operation
    +
    Throws:
    +
    PersistNoneException - if no matching record found
    +
    PersistMultipleException - if more than one record matches
    +
    PersistException - if storage layer throws an exception
    +
  + + + +
  - +
    printNative
    +
```
public boolean printNative()
```
    +
    Description copied from interface: Query
    +
    Print the native query to standard out, which is useful for performance + analysis. Not all repositories have a native query format. An example + native format is SQL.
    +
    +
    Specified by:
    +
    printNative in interface Query<S extends Storable>
    +
    Returns:
    false if not implemented
    +
  + + + +
  - +
    printNative
    +
```
public boolean printNative(java.lang.Appendable app)
+                    throws java.io.IOException
```
    +
    Description copied from interface: Query
    +
    Prints the native query to any appendable, which is useful for + performance analysis. Not all repositories have a native query + format. An example native format is SQL.
    +
    +
    Specified by:
    +
    printNative in interface Query<S extends Storable>
    +
    Parameters:
    app - append results here
    +
    Returns:
    false if not implemented
    +
    Throws:
    +
    java.io.IOException
    +
  + + + +
  - +
    printPlan
    +
```
public boolean printPlan()
```
    +
    Description copied from interface: Query
    +
    Prints the query excecution plan to standard out, which is useful for + performance analysis. There is no standard format for query plans, nor + is it a requirement that this method be implemented.
    +
    +
    Specified by:
    +
    printPlan in interface Query<S extends Storable>
    +
    Returns:
    false if not implemented
    +
  + + + +
  - +
    printPlan
    +
```
public boolean printPlan(java.lang.Appendable app)
+                  throws java.io.IOException
```
    +
    Description copied from interface: Query
    +
    Prints the query excecution plan to any appendable, which is useful for + performance analysis. There is no standard format for query plans, nor + is it a requirement that this method be implemented.
    +
    +
    Specified by:
    +
    printPlan in interface Query<S extends Storable>
    +
    Parameters:
    app - append results here
    +
    Returns:
    false if not implemented
    +
    Throws:
    +
    java.io.IOException
    +
  + + + +
  - +
    toString
    +
```
public java.lang.String toString()
```
    +
    Implementation calls appendTo.
    +
    +
    Specified by:
    +
    toString in interface Query<S extends Storable>
    +
    Overrides:
    +
    toString in class java.lang.Object
    +
    +
  + + + +
  - +
    hashCode
    +
```
public abstract int hashCode()
```
    +
    +
    Specified by:
    +
    hashCode in interface Query<S extends Storable>
    +
    Overrides:
    +
    hashCode in class java.lang.Object
    +
    +
  + + + +
  - +
    equals
    +
```
public abstract boolean equals(java.lang.Object obj)
```
    +
    +
    Specified by:
    +
    equals in interface Query<S extends Storable>
    +
    Overrides:
    +
    equals in class java.lang.Object
    +
    +
  + + + +
  - +
    checkSliceArguments
    +
```
protected boolean checkSliceArguments(long from,
+                          java.lang.Long to)
```
    +
    Called by sliced fetch to ensure that arguments are valid.
    +
    Returns:
    false if from is 0 and to is null
    +
    Throws:
    +
    java.lang.IllegalArgumentException - if arguments are invalid
    Since:
    +
    1.2
    +
  +
+

Class AbstractQuery<S extends Storable>

Nested Class Summary

Nested classes/interfaces inherited from interface com.amazon.carbonado.Query

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface com.amazon.carbonado.Query

Methods inherited from interface com.amazon.carbonado.util.Appender

Constructor Detail

AbstractQuery

Method Detail

and

or

fetchAfter

fetchAfter

loadOne

loadOne

tryLoadOne

tryLoadOne

deleteOne

deleteOne

printNative

printNative

printPlan

printPlan

toString

hashCode

equals

checkSliceArguments