ReportWorkshop Overview | Template syntax | Data Fields

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ReportWorkshop Overview | Template syntax | Data Fields

See the topic about fields in templates for a general description of the syntax.

Syntax

<data field> ::= [']<full data field name>['][ <field type>][ "<format>"]

<full data field name> ::= [<query processor>]<field name>

Full data field name may be enclosed in single quotes. These single quotes are necessary if <query processor> or <field name> contain space characters.

<query processor> ::= <rule>: | : | ^+:

<field name> is a name of a field in a table generated by the rule.

Field names are case insensitive.

<field type> – see data field types section below.

<format> – see data field format strings section below.

About data fields

Data fields allow retrieving values returned by query processors. A query processor may be created to process the following data queries:

root data query

table row generation rule's data query

table cell's data query

A query processor is referred in <query processor>.

If it is omitted, the results of the current (most deeply nested) query processor are used.

If only ':' is included, the results of the root query processor are used (the root query processor is a query processor created for root data query; if this data query is not assigned, there is no root query processor).

If an identifier <rule> is included, a query processor for the table row generation rule with name = <rule> is used.

Special values:

'^' the parent query processor

'^^' the parent of the parent query processor

and so on

Table cell's query processors cannot be referred by a name. So they can be referred only as current or parent query processors.

hmtoggle_arrow1Examples

Data field types

A report generator supports the following types of fields:

text

integer value

floating point value

boolean (logical)

date, time, date and time

memo (a text document in ANSI or Unicode)

RTF document (normal RTF and RTF converted to a Unicode string)

RVF document

image (bitmap, icon, metafile, jpeg, gif, png, tiff, if graphic classes for these formats are available).

additional field types implemented by programmers

If not specified, a format returned by TRVReportQueryProcessor.GetFieldType is used.

You can override the field type by specifying <field type>, read the topic about specifying data field types.

Data field format strings

Read the topic about format strings.

Use

A data field can be used:

to insert its value in a template text;

to insert a text representation of its value in a string (such as a data query or a hyperlink target)

as a parameter of If, IfDef, IfNDef commands.

Examples

These examples use SQL-based data queries.

Example 1: basic example

Let a cell's data query = 'SELECT first_name, last_name FROM persons'.

Let a data processor returns two records: ('John', 'Smith') and ('Mary', 'Black').

The cell contains:

{first_name} {last_name}

It produces:

John Smith
Mary Black

Example 2: master-detail

Let we have two database tables: master_table and detail_table.

Let there is report table having a row generation rule with the data query = 'SELECT master_id from master_table'.

Let this table has a cell (in a row affected by this rule) having the data query = 'SELECT * from detail_table WHERE master_id={master_id}'

As a result, we have a master-detail report.

Example 3

Let we have three database tables: sellers, products, sales. The "sales" table contains fields: seller_id, product_id, quantity, date (so it establish "N to N" relation between sellers and products).

Let there is table having a row generation rule with the data query = 'SELECT seller_id from sales', name = 'sellers_rule'.

It has a nested table, having a row generation rule with the data query = 'SELECT product_id from products', name = 'products_rule'.

In its order, it has a nested table, having a row generation rule with the data query = 'SELECT quantity, date WHERE seller_id={sellers_rule:seller_id} AND product_id={products_rule:product_id}'.

As a result, we have a report of sales grouped first by products, then by sellers.

Note: since, for the third table, 'products_rule' is the most recent rule, we could omit 'products_rule:' in '{products_rule:product_id}'.