MarkLogic 9 Product Documentation
xdmp.xqueryEvalxdmp.xqueryEval(
xquery as String,
[vars as Object?],
[options as Object?]
) as Sequence
Summary
Returns the result of evaluating a string as an XQuery module. Options are
as per the XQuery function xdmp:eval.
| Parameters |
| xquery |
A string containing the XQuery code to be evaluated. If the
string contains double quotes ("), surround the string with single
quotes (').
|
| vars |
External variable values to make available to the evaluated code,
expressed as a JavaScript Object. Each property name is a variable
QName, and its value is the corresponding variable value. Use Clark
notation to represent QNames with a namespace qualifer. That is, use
a name of the form ('{namespaceURI}localname'). For example,
{ '{http://my/ns}num': 42 } specifies that the value of the variable
named 'num' in the namespace 'http://my/ns' is 42. You can use
the function xdmp.keyFromQName
to generate Clark notation for a QName.
|
| options |
Options with which to customize this operation.
Specify your options as a JavaScript object, with the option names as
the object property names. This function supports the following options:
- database
- The id of the content database. You can use functions such as
xdmp.database to get a database ID. See the Usage
Notes for more details. Use of this option to specify a database
other than the context database requires additional privileges.
For details, see Required Privileges, below.
- modules
- The ID of the modules database to use for resolving module imports.
If you do not specify a
modules option, this operation
uses the current modules database. Use a value of 0 to
specify using the file system to resolve module imports. Use of this
option may require additional privileges. For details, see Required
Privileges, below.
- root
- The root path for modules. If you do not explicitly specify a
root option, the current root is used. Use of this
option may require additional privileges. For details, see Required
Privileges, below.
- timestamp
- The system timestamp to use for this evaluation. If you omit this
option, the most recent timestamp is used. You may only specify a
timestamp for a query statement, not for an update statement. Use a
value of zero to specify the current system timestamp (the value that
would be returned by
xdmp.requestTimestamp).
For more details, see
Understanding Point-In-Time Queries in the Application Developer's Guide.
Use of this option requires additional privileges. For details, see
Required Privileges, below.
- ignoreAmps
-
Whether or not to evaluate the code without using any Amps from the caller.
Allowed values: true, false (default). If this option is set to
true, the code is evaluated without using Amps from the
caller. For more details, see
Temporarily Increasing Privileges with Amps in the Security Guide.
- isolation
- Specify the transaction isolation for this operation. Allowed values:
same-statement, different-transaction (default).
When set to same-statement, the evaluation occurs in the
same transaction in which this function is called. When set to
different-transaction, the evaluation occurs in a separate
transaction from the one in which this function is called. If you use
same-statement isolation in a query (read-only) statement
and the eval'd code attempts an update, MarkLogic throws the exception
XDMP-UPDATEFUNCTIONFROMQUERY. For more details, see
Isolation Option to xdmp:eval/invoke in the Application Developer's Guide.
- commit
-
The commit mode for the transaction in which the code is evaluated.
Allowed values:
auto (default), explicit.
In auto mode, a transaction is committed for every statement.
In explicit mode, the transaction must be explicitely
committed or rolled back. For more details, see
Commit Mode in the Application Developer's Guide.
- update
-
Specify the transaction type in which to evaluate this code, or let
MarkLogic determine the transaction type. Allowed values:
"true", "false", "auto" (default).
For more details, see
Transaction Type Overview in the Application Developer's Guide.
- staticCheck
-
Whether or not to only perform a static analysis of the code, without
executing it. Allowed values:
true, false
(default).
- preventDeadlocks
-
Whether or not to disallow update requests from an update transaction.
Allowed values:
true, false (default). This
option only has an effect when you set the isolation option
to different-transaction since there is no possibility of
deadlock if the isolation is same-statement. When you set
this option to true in an update request calling another
update request, MarkLogic throws the exception
XDMP-PREVENTDEADLOCKS. Setting this option to
true prevents deadlocks from occurring when evaluating
or invoking an update transaction from another update transaction.
For more details, see
Preventing Deadlocks in the Application Developer's Guide.
- defaultXqueryVersion
- The default XQuery language version to use for the query, if the query
does not contain an explicit version declaration. If this option is not
provided, then MarkLogic uses the default XQuery version for the
App Server that called this function. The version may vary from module
to module if a query consists of modules written in multiple XQuery
versions. If may also var from run to run if the App Server default
changes across runs.
Allowable values for this option are "0.9-ml", "1.0-ml", "1.0", and
the special value "app-server". The first three are XQuery language
versions. The last indicates that the default XQuery language
version set on this App Server should be used. This is useful if code
written in an older XQuery version needs to call this function
on strings that may have been passed as parameters, but should be
interpreted in the App Server default language version. A module
may discover its own XQuery language version with
xdmp.xqueryVersion().
- userId
- The ID of the user under which this operation should be performed.
If you do not set this option, the operation is performed as the
current user. Use of this option requires additional privileges. For
details, see Required Privileges, below. NOTE: This is a very
privileged operation since it enables a user to evaluate requests
as any other user.
- defaultCollation
- Specifies the collation to use for this operation if a collation
is not explicitly specified, such as in the XQuery prolog or in a
function call that allows you to specify a collation. For more
details, see
Encodings and Collations in the Search Developer's Guide.
- defaultCoordinateSystem
- Specifies the geospatial coordinate system to use for this operation,
if a coordinate system is not explicitly specified, such as in the XQuery prolog
or in a function call that allows you to specify a coordinate system.
For more details, see
Controlling Coordinate System and Precision in the Search Developer's Guide and
Supported Coordinate Systems in the Search Developer's Guide.
- transactionMode
- [DEPRECATED: Use the
update and commit
options instead.] Explicitly set the transaction mode for this context.
Allowed values: auto (default), query,
update-auto-commit, update. For details, see
Transaction Mode in the Application Developer's Guide.
For simple updates to be implicitly committed, specify a transaction
mode of update-auto-commit. A transaction mode of
update creates a new multi-statement update
transaction and requires an explicit commit in the code.
Within a session there can be only one active multi-statement
transaction at a time. If a new multi-statement transaction is
specified nested inside a multi-statement transaction, MarkLogic throws
the exception XDMP-NESTEDMULTI. If a new multi-statement
transaction is specified after another has been concurrently created
in the same session by another request, MarkLogic throws the exception
XDMP-SESSIONTXN and retries the current request.
An xdmp:transaction-mode declaration in the prolog of
the evaluated code overrides any transaction mode specified
with this option.
|
Required Privileges
To use this function, you must have the following privilege:
http://marklogic.com/xdmp/privileges/xdmp-eval
To use the database option to specify a content database
other than the default database for the current App Server, you must
have the following privilege:
http://marklogic.com/xdmp/privileges/xdmp-eval-in
To use the modules or root options to specify
to specify a modules database or root other than that configured for the
current App Server, you must have the following privilege:
http://marklogic.com/xdmp/privileges/xdmp-eval-modules-change
To use the modules or root options to specify
to specify using the file system as the modules database or root path, you
you must have the following privilege:
http://marklogic.com/xdmp/privileges/xdmp-eval-modules-change-file
To use the
userId option, you must have the
following privilege:
http://marklogic.com/xdmp/privileges/xdmp-login
To use the timestamp option, you must have the following
privileges:
http://marklogic.com/xdmp/privileges/xdmp-timestamp
Usage Notes
To get the database ID for options that require one, such as
the database or modules options, you can use
functions such as the following. Use the function appropriate to the
database you want to reference.
See Also
Example
xdmp.xqueryEval(" 'hello world, today is: ', fn:current-dateTime() ");
=>
hello world, today is:
2015-01-21T14:24:50.453913-08:00
Example
'use strict';
const counts = [];
for (const uri of cts.uriMatch('/my/*')) {
const p = xdmp.documentProperties(uri);
const count = xdmp.xqueryEval('declare namespace bar="bar";' + 'fn:count(' + p + '//bar:foo)')
counts.push(count)
}
counts
=>
[1]
Example
'use strict';
let query = cts.wordQuery('bye');
console.log(this.query)
xdmp.xqueryEval('xquery version "1.0-ml";' +
'import module namespace search = "http://marklogic.com/appservices/search" at "/MarkLogic/appservices/search/search.xqy";' +
'declare variable $query as cts:query external;' +
'search:resolve($query,' +
'<options xmlns="http://marklogic.com/appservices/search"><searchable-expression>doc()</searchable-expression></options>' +
')', {
query: query
})
=>
<search:response snippet-format="snippet" total="1" start="1" page-length="10" xmlns:search="http://marklogic.com/appservices/search">
<search:result index="1" uri="/my/doc.xml" path="fn:doc("/my/doc.xml")" score="2048" confidence="0" fitness="0.2357023">
<search:snippet>
<search:match path="fn:doc("/my/doc.xml")/*:foo/*:hello/*:goodbye"><search:highlight>bye</search:highlight></search:match>
</search:snippet>
</search:result>
<search:metrics>
<search:query-resolution-time>PT0.0030003S</search:query-resolution-time>
<search:snippet-resolution-time>PT0.0010001S</search:snippet-resolution-time>
<search:total-time>PT0.0060006S</search:total-time>
</search:metrics>
</search:response>
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