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This section is not intended to be a course of the SQL language. Therefore, the focus will be put on the minimal set of differences that you must know in order to write queries properly.

...

Expand
titleExample

Code Block
languagesql
select * from PROJECT

will work.

Whereas

Code Block
languagesql
select * from project

will not.

KEY is a reserved word

As other database vendors, SQL Cloud does have reserved words that must be surrounded with accents or square brackets

...

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titleRead more...

This can cause series reliability problems and compromise the Jira server instance performance.

A clear example is:

Code Block
languagesql
SELECT * FROM ISSUE

What if there are millions of records/issues?

Therefore many queries performing full scans on tables are aborted by the SQL Cloud engine by raising a Full Scan error:

Since SQL Cloud is a wrapper for the Atlassian’s Jira public REST API, it relies on the underlaying Atlassian’s API for that. In other words, if the Jira REST API allows querying for all the results (i.e.: PROJECTs), then SQL Cloud will allow it too. Otherwise (i.e.: ISSUEs) not. In this case the indexed column names are displayed (JQL and ID in the example above).

An indexed column in SQL Cloud corresponds to a filter parameter required by the Atlassian’s Jira public REST API to fetch data from Jira. For instance, you can search for issues in Jira by ID or by JQL query.

In general, the SQL Cloud is an straightforward implementation of the Jira REST API and inherits the same security and the rest of the constraints.

WHERE conditions are not the same as JOIN conditions

In SQL Cloud there is a big difference about how values are provided for dynamic table resolution (fetching data from Jira to populate them).

This is very important to write working queries that perform in the right way.

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titleRead more...

These are the rules for conditions resolution:

  1. The table in FROM clause will get the conditions from the WHERE clause directly

  2. The rest of the tables will take them from the JOIN ON conditions only.

In other words,

  1. WHERE conditions will be applied only to the table only (FROM) at the beginning of the query execution.

  2. JOINs will be resolved taking only ON conditions (WHERE will be ignored here at this stage)

  3. The rest of the WHERE conditions will be applies to filter the JOIN (2) results.

Aggregation conditions do not support aliases

Expand
titleExample

Please pay attention to the having condition: count(*) > 2

Code Block
languagesql
SELECT `i`.`KEY`as `Issue`, count(*) as `Num. comments`
FROM ISSUE `i`
LEFT JOIN ISSUECOMMENT `ic` ON `ic`.`ISSUEID` = `i`.`ID`
WHERE `i`.`JQL` = 'PROJECT = TALH'
GROUP BY `i`.`KEY`
HAVING count(*) > 2

Works!

In this query the condition has been modified to uses column aliases: `Num. comments` > 2

Code Block
SELECT `i`.`KEY`as `Issue`, count(*) as `Num. comments`
FROM ISSUE `i`
LEFT JOIN ISSUECOMMENT `ic` ON `ic`.`ISSUEID` = `i`.`ID`
WHERE `i`.`JQL` = 'PROJECT = TALH'
GROUP BY `i`.`KEY`
HAVING `Num. comments` > 2

Not works!