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5Introducing the CFX API

Working with Queries

Any CFX tag may return queries to the ColdFusion page that is calling the tag. The queries can

then be used in ColdFusion code, just like the results of a

<cfquery> or any other tag that returns a

recordset. For instance, the queries can be used as the

query parameter of a <cfloop> or <cfoutput>

tag; they can even be re-queried or joined with other recordsets using in-memory-queries (where

you set

dbtype=”query” in a separate <cfquery> tag; also known as “query-of-queries”). Table 30.6

shows the Java methods for working with queries, and Table 30.7 shows the C++ versions.

NOTE

Any CFX tag can return any number of queries to the calling template, but it can only access the data in one query that already exists

in the calling template. To put it another way, multiple queries can be passed out from the CFX, but only one can be passed in.

Table 30.6 Java Methods for Working with Queries

METHOD DESCRIPTION

response.addQuery(name, columns) Creates a new query, which will be available in the

calling ColdFusion page when the CFX tag ﬁnishes

executing. Specify the

name of the query as a string,

and specify its

columns as an array of strings.

query.addRow() Adds a row to the query. You can then ﬁll the

individual cells (columns) of the new row using

setData(). Returns the row number of the new

row, as an

int.

query.setData(row, col, value) Places the value (which must be a string) into the

query at the row and column position you specify.

Rows and columns are both numbered beginning

with 1. You can get the value for

col using

getColumnIndex().

request.getQuery() Retrieves the query (if any) that was passed to the

CFX tag. Returns a

Query object, or null if no

QUERY attribute was provided.

query.getColumnIndex(name) Returns the column index (position) of the column

with the given name. You can then use the index to

specify columns to

getData() and setData().

Returns

-1 if the column doesn’t exist.

query.getColumns() Returns the names of the query’s columns, as an

array of strings.

query.getData(row, col) Returns the value in the query at the given row and

column position. The value is always returned as a

string.

query.getName() Returns the name of the query (as a string), as it is

known in the calling ColdFusion page.

query.getRowCount() Returns the number of rows in the query, as an int.

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