Add ability to set escape tokens within literals
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Key: TEIID-3691
URL:
https://issues.jboss.org/browse/TEIID-3691
Project: Teiid
Issue Type: Bug
Components: Query Engine
Reporter: Don Krapohl
Assignee: Steven Hawkins
A mismatch of escape sequences exists between Teiid and some databases (Impala for sure).
Teiid uses doubled up quotes for single/double whereas some databases expect C-style
escapes like \' or \". When string literals are pushed down they fail to parse
on the underlying database using Teiid's escapes.
Teiid uses multiple quotes to escape a single within a string literal. Example would be
searching for the string literal Haggley's within single quotes. In Teiid the parser
will fail with a parser error using any of these options:
* Surround with double quotes ("Haggley's")
* Escape with C-style escape ('Haggley\'s')
Making the query parse in Teiid the filter value would be 'Haggley''s'.
When pushed down into the database this is not valid syntax and should be translated as
'Haggley\'s' or other escape sequence as appropriate to the underlying data
store.