Query Language Reference (Version 0.7)

http://code.google.com/intl/ru/apis/visualization/documentation/querylanguage.html

Query Language Reference (Version 0.7)

The Google Visualization API Query Language lets you perform various data manipulations with the query to the data source.

Table of Contents

1. Introduction
2. Using the Query Language
   1. Setting the Query from JavaScript
   2. Setting the Query in the Data Source URL
3. Language Syntax
   1. Overview
   2. Language Clauses
      1. Select
      2. Where
      3. Group By
      4. Pivot
      5. Order By
      6. Limit
      7. Offset
      8. Label
      9. Format
      10. Options
   3. Data Manipulation Functions
      1. Aggregation Functions
      2. Scalar Functions
      3. Arithmetic Operators
   4. Language Elements
      1. Literals
      2. Identifiers
      3. Case Sensitivity
      4. Reserved Words

Introduction

Typically, visualizations expect data in some specific form. For example, a pie chart may expect data as two columns: a text label and a numeric value. The data within the data source may not exactly match this structure. For example the data source may have more than two columns, or the order of the columns may not match the order expected by the pie chart.

The query language provides the ability to send data manipulation and formatting requests to the data source, and ensure that the returned data structure and contents match the expected structure.

The syntax of the query language is similar to SQL. Developers familiar with SQL should be able to quickly learn and use this query language. There are many SQL tutorials available on the Web. There are some differences between this query language and SQL which are described in the syntax section.

Note that data sources are not required to implement the query language, or if they do, to implement all features of the language. Unless you have reason to believe otherwise, you should not depend on a data source to implement all features of this language.

Using the Query Language

You can attach a query string to a data source request in two ways: by setting the query string from within JavaScript code, or by setting the query string as a parameter in the data source URL. If your request does not include a query string, the default behavior for a data source is to return all rows and columns using its default row/column order and formatting. You can change that by including a query string in your request to a data source.