Class SQLEmbed
- java.lang.Object
-
- org.apache.openjpa.jdbc.kernel.exps.SQLEmbed
-
- All Implemented Interfaces:
java.io.Serializable
,JDBCFilterListener
,FilterListener
- Direct Known Subclasses:
SQLExpression
,SQLValue
public class SQLEmbed extends java.lang.Object implements JDBCFilterListener
Simple listener which embeds its SQL argument into the query. Listens onsql
. Example:
"price < sql(\"(SELECT AVG (PRICE) FROM PRODUCT_TABLE)\")"
- See Also:
- Serialized Form
-
-
Field Summary
Fields Modifier and Type Field Description static java.lang.String
TAG
-
Constructor Summary
Constructors Constructor Description SQLEmbed()
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
appendTo(SQLBuffer buf, FilterValue target, FilterValue[] args, ClassMapping type, JDBCStore store)
Append the SQL for this expression or value.java.lang.Object
evaluate(java.lang.Object target, java.lang.Class targetClass, java.lang.Object[] args, java.lang.Class[] argClasses, java.lang.Object candidate, StoreContext ctx)
Evaluate the given expression.boolean
expectsArguments()
Return true if this extension expects arguments to act on.boolean
expectsTarget()
Return true if this extension expects a target to act on.java.lang.String
getTag()
Return the tag that this extension listens for.java.lang.Class
getType(java.lang.Class targetClass, java.lang.Class[] argClasses)
Return the expected type of the result of this listener.
-
-
-
Method Detail
-
getTag
public java.lang.String getTag()
Description copied from interface:FilterListener
Return the tag that this extension listens for.- Specified by:
getTag
in interfaceFilterListener
-
expectsArguments
public boolean expectsArguments()
Description copied from interface:FilterListener
Return true if this extension expects arguments to act on. Some extensions may not need arguments; for example, an extension to switch a string to upper case might be of the form:field.ext:toUpperCase ()
.- Specified by:
expectsArguments
in interfaceFilterListener
-
expectsTarget
public boolean expectsTarget()
Description copied from interface:FilterListener
Return true if this extension expects a target to act on. Some extensions act on a field or object value; others stand alone.field.ext:toUpperCase ()
acts on the targetfield
but has no arguments, while another possible form,ext:toUpperCase (field)
has no target but does have an argument.- Specified by:
expectsTarget
in interfaceFilterListener
-
evaluate
public java.lang.Object evaluate(java.lang.Object target, java.lang.Class targetClass, java.lang.Object[] args, java.lang.Class[] argClasses, java.lang.Object candidate, StoreContext ctx)
Description copied from interface:FilterListener
Evaluate the given expression. This method is used when evaluating in-memory expressions. The method used when evaluating data store expressions will change depending on the data store in use.- Specified by:
evaluate
in interfaceFilterListener
- Parameters:
target
- the target object / field value to act on; will be null if this extension does not expect a targettargetClass
- the expected class of the target; given in case the target evaluates to null and typing is neededargs
- the values of the arguments given in the filter; will be null if this extension does not expect an argumentargClasses
- the expected classes of the arguments; given in case an argument evaluates to null and typing is neededcandidate
- the candidate object being evaluatedctx
- the persistence context- Returns:
- the value of the extension for this candidate; if
this extension is an expression, this method should
return
Boolean.TRUE
orBoolean.FALSE
-
appendTo
public void appendTo(SQLBuffer buf, FilterValue target, FilterValue[] args, ClassMapping type, JDBCStore store)
Description copied from interface:JDBCFilterListener
Append the SQL for this expression or value.- Specified by:
appendTo
in interfaceJDBCFilterListener
- Parameters:
buf
- the SQL buffer to append totarget
- the target to act on, or null if the listener doesn't expect a targetargs
- the values of the arguments given in the filter, or null if this listener doesn't expect argumentstype
- the class mapping for the query's candidate classstore
- the store that owns the query
-
getType
public java.lang.Class getType(java.lang.Class targetClass, java.lang.Class[] argClasses)
Description copied from interface:FilterListener
Return the expected type of the result of this listener.- Specified by:
getType
in interfaceFilterListener
- Parameters:
targetClass
- the expected class of the target, or null if no targetargClasses
- the expected classes of the arguments, or null if no arguments
-
-