[teiid-issues] [JBoss JIRA] (TEIID-5965) Allow variables to be used as TextTable delimeters, row delimeters, quote, header, skip rows, and escape characters

[Steven Hawkins (Jira)]

     [ https://issues.redhat.com/browse/TEIID-5965?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Steven Hawkins updated TEIID-5965:
----------------------------------
    Fix Version/s: Backlog
                       (was: 15.0)


> Allow variables to be used as TextTable delimeters, row delimeters, quote, header, skip rows, and escape characters
> -------------------------------------------------------------------------------------------------------------------
>
>                 Key: TEIID-5965
>                 URL: https://issues.redhat.com/browse/TEIID-5965
>             Project: Teiid
>          Issue Type: Enhancement
>          Components: Query Engine
>    Affects Versions: 13.1
>            Reporter: Dmitrii Pogorelov
>            Assignee: Steven Hawkins
>            Priority: Minor
>             Fix For: Backlog
>
>   Original Estimate: 5 hours
>          Time Spent: 1 hour
>  Remaining Estimate: 4 hours
>
> In the specified example, the delimiter is TAB. Many web APIs allow customization of the delimiter character, and in order to provide a generic parser, sometimes it is way easier to define a delimiter as a variable, and not need to create a long nested structure with IF-THEN-ELSE-IF-ELSE constructs:
> {code:sql}
> Select * From TextTable (
> 	'c1	c2
> 1	2'
> 	Columns
> 		c1 integer,
> 		c2 integer
> 	Delimiter E'\t'
> 	Header 1
> )x;
> {code}
> Imagine that based on setup on API side (out of our control) the content can be delivered via tab or semicolon, e.g.
> {code}
> c1;c2
> 1;2
> {code}
> or
> {code}
> c1	c2
> 1	2
> {code}
> Let's save this response into a variable and see the code, which we will need to write depending on the setup:
> {code:sql}
> Begin
>     ...
>     If (delimiter = 'tab')
>     Begin
>         Select * From TextTable (
>             apiResponse
>             Columns
>                 c1 integer,
>                 c2 integer
>             Delimiter E'\t'
>             Header 1
>         )x;
>     End
>     Else If (delimiter = 'tab')
>     Begin
>         Select * From TextTable (
>             apiResponse
>             Columns
>                 c1 integer,
>                 c2 integer
>             Delimiter ';'
>             Header 1
>         )x;
>     End
> End
> {code}
> The if-else block is constantly growing, especially if we want to customize quote, escape, delimiter, and row delimiter.
> Thus it would be great if we could make these values configurable. In this case, we could end up with this expected code, which is more readable and more easily customizable:
> {code:sql}
> Begin
>     ...
>     Declare string delimiter = E'\t';
>     Select * From TextTable (
>         apiResponse
>         Columns
>             c1 integer,
>             c2 integer
>         Delimiter delimiter
>         Header 1
>     )x;
> End
> {code}
> With a bit of tweaking and certain assumptions, leading in the trust level, we can even read the first line and try to auto-detect the delimiter automatically (e.g. by counting tabs, commas, and semicolons in the first line).
> Please, could you be so kind as to make HEADER and SKIP values customizable (rather than hardcoded numbers)?



--
This message was sent by Atlassian Jira
(v7.13.8#713008)