== TQL Custom Tags ==

Custom tags for performing TQL based operations.

Documentation on [[Transfer Query Language]]

These custom tags can be used to perform both ''listByQuery' and ''readByQuery' operations via a alternate syntax than their CFC based implementations.

=== query ===

Tag for performing a TQL query.

'''Syntax'''

<source lang="coldfusion">
<query 
     transfer = transfer cfc
     name = "name of the query"
     action = list|read
     class = "transfer class"
     cacheEvaluation = true|false
     distinctMode = true|false
     aliasColumns = true|false
     >
</query>
</source>

'''Attributes'''

{| border="1" cellpadding="2"
! Attribute
! Req/Opt
! Default
! Description
|- 
| transfer
| Required
| -
| The Transfer library, as returned from transferFactory.getTransfer()
|-
| name
| Required
| -
| If ''action=list'', then the name of the variables to return the query to<br/>If ''action=read'', then the name of the variable to return the TransferObject to
|-
| action
| Optional
| 'list'
| ''list:'' performs a [http://docs.transfer-orm.com/html/transferapi/transfer/com/Transfer.html#listByQuery() listByQuery()] operation. <br/> ''read'': performs a [http://docs.transfer-orm.com/html/transferapi/transfer/com/Transfer.html#readByQuery() readByQuery()] operation.
|-
| class
| Required only if ''action=read''
| -
| The class to read when performing the [http://docs.transfer-orm.com/html/transferapi/transfer/com/Transfer.html#readByQuery() readByQuery()] operation.
|-
| cacheEvaluation
| Optional
| true
| Whether or not to cache the evaluation of the TQL, which is good for performance.
|-
| distinctMode
| Optional
| false
| Whether or not to have the resultant SQL run as <code>SELECT DISTINCT...</code>
|-
| aliasColumns
| Optional
| true
| Whether or not to alias the the column names on the resultant Query object with the property names configured in the [[Transfer Configuration File]].
|}

=== queryparam ===

Tag for setting dynamic values within the TQL query.

'''Syntax'''


<source lang="coldfusion">
<query .... >
    <!--- tql --->
    <queryparam
      value = "the value of the parameter"
      type  = string|date|boolean|numeric|GUID|UUID|binary
      list = true|false
      isNull = true|false
      >
    <!--- tql --->
</query>
</source>

'''Attributes'''

{| border="1" cellpadding="2"
! Attribute
! Req/Opt
! Default
! Description
|- 
| value
| Required, unless ''isNull = true''
| -
| The value of the parameter
|-
| type
| Optional
| string
| The type of the value for the parameter, either string, numeric, boolean, GUID, UUID or binary.
|-
| list
| Optional
| false
| Whether or not the value is a delimited list of values, and should be handled separately.
|-
| isNull
| Optional
| false
| Whether the passed in value is actully <code>NULL</code> or not.
|}

=== Examples ===

<source lang="coldfusion">

<cfimport prefix="t" taglib="/transfer/tags">

<!--- Do list operations --->

<t:query name="result" transfer="#getTransfer()#">
        select
                u.firstName, u.lastName
        from
                user.User as u
        where
                u.email like <t:queryparam value="%example.com" type="string">
</t:query>

<!--- Do read operations --->

<!--- Get a single record as a TransferObject --->
<t:query name="user" action="read" class="user.User" transfer="#getTransfer()#">
        from
                user.User as u
        where
                u.email = <t:queryparam value="user@foo.com" type="string">
</t:query>
</source>


[[Category:TQL]]