Package com.saxonica.functions.sql

Class SQLPreparedQueryFn

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

com.saxonica.functions.sql.SQLPreparedQueryFn

All Implemented Interfaces:

Callable, FunctionItem, GroundedValue, Item, Sequence

public class SQLPreparedQueryFn
extends SystemFunction

This class implements the sql:prepared-query() extension function. Arguments:

1. The connection
2. A SQL select statement, typically containing "?" placeholders

The result is a function, with arity equal to the number of placeholders. When calling this function, the supplied arguments substitute for the placeholders in the query, and the result is a sequence of maps containing the rows selected by the query.

Constructor Summary

Constructors

Constructor	Description
SQLPreparedQueryFn()

Method Summary

Modifier and Type	Method	Description
FunctionItem	call(XPathContext context, Sequence[] arguments)	Call the Callable.
static Expression	makePreparedQueryFunction(String tableName, Expression predicate)
static boolean	makeWhereClause(Expression predicate, StringBuilder sb, List<Expression> params)

Methods inherited from class net.sf.saxon.functions.SystemFunction

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getElaborator, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunction40, makeFunctionCall, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, toShortString, toString, typeCheckCaller

Methods inherited from class net.sf.saxon.functions.AbstractFunction

atomize, deepEqual40, deepEquals, effectiveBooleanValue, getAnnotations, getUnicodeStringValue, isArray, isMap, makeNewContext, simplify, typeCheck

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.saxon.om.FunctionItem

getGenre

Methods inherited from interface net.sf.saxon.om.GroundedValue

asIterable, concatenate, containsNode, materialize

Methods inherited from interface net.sf.saxon.om.Item

getLength, getStringValue, head, isStreamed, itemAt, iterate, reduce, subsequence

Methods inherited from interface net.sf.saxon.om.Sequence

makeRepeatable

Constructor Details

SQLPreparedQueryFn

public SQLPreparedQueryFn()

Method Details

call

public FunctionItem call(XPathContext context,
 Sequence[] arguments)
                  throws XPathException

Description copied from interface: Callable

Call the Callable.

Parameters:

context - the dynamic evaluation context

arguments - the values of the arguments, supplied as Sequences.

Generally it is advisable, if calling iterate() to process a supplied sequence, to call it only once; if the value is required more than once, it should first be converted to a GroundedValue by calling the utility method SequenceTool.toGroundedValue().

If the expected value is a single item, the item should be obtained by calling Sequence.head(): it cannot be assumed that the item will be passed as an instance of Item or AtomicValue.

It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.

Returns:

the result of the evaluation, in the form of a Sequence. It is the responsibility of the callee to ensure that the type of result conforms to the expected result type.

Throws:

XPathException - if a dynamic error occurs during the evaluation of the expression

makePreparedQueryFunction

public static Expression makePreparedQueryFunction(String tableName,
 Expression predicate)

makeWhereClause

public static boolean makeWhereClause(Expression predicate,
 StringBuilder sb,
 List<Expression> params)