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Statements

SHOW TABLES statement

SHOW TABLES can be used to list the tables on your account. The table name is the name you specified as dataset when configuring the workers binding (refer to Get started with Workers Analytics Engine, for more information). The table is automatically created when you write event data in your worker.

SHOW TABLES
[FORMAT <format>]

Refer to FORMAT clause for the available FORMAT options.

SHOW TIMEZONES statement

SHOW TIMEZONES can be used to list all of the timezones supported by the SQL API. Most common timezones are supported.

SHOW TIMEZONES
[FORMAT <format>]

SHOW TIMEZONE statement

SHOW TIMEZONE responds with the current default timezone in use by SQL API. This should always be Etc/UTC.

SHOW TIMEZONE
[FORMAT <format>]

SELECT statement

SELECT is used to query tables.

Usage:

SELECT <expression_list>
[FROM <table>|(<subquery>)]
[WHERE <expression>]
[GROUP BY <expression>, ...]
[ORDER BY <expression_list>]
[LIMIT <n>|ALL]
[FORMAT <format>]

Below you can find the syntax of each clause. Refer to the SQL API documentation for some example queries.

SELECT clause

The SELECT clause specifies the list of columns to be included in the result. Columns can be aliased using the AS keyword.

Usage:

SELECT <expression> [AS <alias>], ...

Examples:

-- return the named columns
SELECT blob2, double3


-- return all columns
SELECT *


-- alias columns to more descriptive names
SELECT
    blob2 AS probe_name,
    double3 AS temperature

Additionally, expressions using supported functions and operators can be used in place of column names:

SELECT
    blob2 AS probe_name,
    double3 AS temp_c,
    double3*1.8+32 AS temp_f -- compute a value


SELECT
    blob2 AS probe_name,
    if(double3 <= 0, 'FREEZING', 'NOT FREEZING') AS description -- use of functions


SELECT
    blob2 AS probe_name,
    avg(double3) AS avg_temp -- aggregation function

FROM clause

FROM is used to specify the source of the data for the query.

Usage:

FROM <table_name>|(subquery)

Examples:

-- query data written to a workers dataset called "temperatures"
FROM temperatures


-- use a subquery to manipulate the table
FROM (
    SELECT
        blob1 AS probe_name,
        count() as num_readings
    FROM
        temperatures
    GROUP BY
        probe_name
)

Note that queries can only operate on a single table. UNION, JOIN etc. are not currently supported.

WHERE clause

WHERE is used to filter the rows returned by a query.

Usage:

WHERE <condition>

<condition> can be any expression that evaluates to a boolean.

Comparison operators can be used to compare values and boolean operators can be used to combine conditions.

Expressions containing functions and operators are supported.

Examples:

-- simple comparisons
WHERE blob1 = 'test'
WHERE double1 = 4


-- inequalities
WHERE double1 > 4


-- use of operators (see below for supported operator list)
WHERE double1 + double2 > 4
WHERE blob1 = 'test1' OR blob2 = 'test2'


-- expression using inequalities, functions and operators
WHERE if(unit = 'f', (temp-32)/1.8, temp) <= 0

GROUP BY clause

When using aggregate functions, GROUP BY specifies the groups over which the aggregation is run.

Usage:

GROUP BY <expression>, ...

For example, if you had a table of temperature readings:

-- return the average temperature for each probe
SELECT
    blob1 AS probe_name,
    avg(double1) AS average_temp
FROM temperature_readings
GROUP BY probe_name

In the usual case the <expression> can just be a column name but it is also possible to supply a complex expression here. Multiple expressions or column names can be supplied separated by commas.

ORDER BY clause

ORDER BY can be used to control the order in which rows are returned.

Usage:

ORDER BY <expression> [ASC|DESC], ...

<expression> can just be a column name.

ASC or DESC determines if the ordering is ascending or descending. ASC is the default, and can be omitted.

Examples:

-- order by double2 then double3, both in ascending order
ORDER BY double2, double3


-- order by double2 in ascending order then double3 is descending order
ORDER BY double2, double3 DESC

LIMIT clause

LIMIT specifies a maximum number of rows to return.

Usage:

LIMIT <n>|ALL

Supply the maximum number of rows to return or ALL for no restriction.

For example:

LIMIT 10 -- return at most 10 rows

OFFSET clause

OFFSET specifies a number of rows to skip in the query result.

Usage:

OFFSET <n>

For example:

OFFSET 10 -- skip the first 10 result rows

FORMAT clause

FORMAT controls how to the returned data is encoded.

Usage:

FORMAT [JSON|JSONEachRow|TabSeparated]

If no format clause is included then the default format of JSON will be used.

Override the default by setting a format. For example:

FORMAT JSONEachRow

The following formats are supported:

JSON

Data is returned as a single JSON object with schema data included:

{
    "meta": [
        {
            "name": "<column 1 name>",
            "type": "<column 1 type>"
        },
        {
            "name": "<column 2 name>",
            "type": "<column 2 type>"
        },
        ...
    ],
    "data": [
        {
            "<column 1 name>": "<column 1 value>",
            "<column 2 name>": "<column 2 value>",
            ...
        },
        {
            "<column 1 name>": "<column 1 value>",
            "<column 2 name>": "<column 2 value>",
            ...
        },
        ...
    ],
    "rows": 10
}

JSONEachRow

Data is returned with a separate JSON object per row. Rows are newline separated and there is no header line or schema data:

{"<column 1 name>": "<column 1 value>", "<column 2 name>": "<column 2 value>"}
{"<column 1 name>": "<column 1 value>", "<column 2 name>": "<column 2 value>"}
...

TabSeparated

Data is returned with newline separated rows. Columns are separated with tabs. There is no header.

column 1 value  column 2 value
column 1 value  column 2 value
...