[
https://issues.apache.org/jira/browse/DERBY-693?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15407143#comment-15407143
]
Leshan Bashitha Wijegunawardana commented on DERBY-693:
-------------------------------------------------------
I'm a computer engineering undergraduate who is new to the Apache Derby code
base. According to the explanation here I understood that this issue can be
overcome by setting prevCharIsLF flag to false before calling UpdateLineColumn
method. When I go through the UCode_CharStream class there is one place that
the UpdateLineColumn method is called. That is in the readChar method. So I
hope this can be overcome by setting prevCharIsLF flag to false before calling
UpdateLineColumn method in the readChar method. Is that ok? Else can anyone
explain me the issue liittle bit.
Thanks.
> Incorrect line number in the error message when parser throws syntax error in
> some specific examples
> ----------------------------------------------------------------------------------------------------
>
> Key: DERBY-693
> URL: https://issues.apache.org/jira/browse/DERBY-693
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.2.1.6
> Reporter: Mamta A. Satoor
> Priority: Minor
> Labels: derby_triage10_5_2
> Attachments: w.sql
>
>
> After connecting to a database through ij, parser returns correct line number
> for the sql "select" the first time around but it returns incorrect line
> number when the same sql is rexecuted, as shown below
> $ java org.apache.derby.tools.ij
> ij version 10.2
> ij> connect 'jdbc:derby:c:/dellater/db1';
> ij> select
> ;
> ERROR 42X01: Syntax error: Encountered "<EOF>" at line 1, column 8.
> ij> select
> ;
> ERROR 42X01: Syntax error: Encountered "<EOF>" at line 2, column 8.
> ij>
> This is caused by UCode_CharStream's UpdateLineColumn method. When the sql
> "select" is executed the first time, the parser comes to UpdateLineColumn
> method for trailing \r and then for trailing \n for the first line "select".
> The trailing \n causes the prevCharIsLF to be set to true. Since this sql is
> incorrect by itself, parser will throw a syntax error. After the exception
> and before the processing of next sql "select", this prevCharIsLF flag does
> not get set to false(this is the problem). When the first character "s" is
> read, UpdateLineColumn checks if prevCharIsLF set to true and if yes, it
> increments(incorrectly) the line number to 2 and that is why the second time
> around, execution of "select" gives syntax error at line 2 rather than line 1.
> This also causes problem with the optimizer hints when they are used in
> incorrect context as shown below.
> $ java org.apache.derby.tools.ij
> ij version 10.2
> ij> connect 'jdbc:derby:c:/dellater/db1';
> ij> -- derby-properties
> select * from t1;
> ERROR 42X01: Syntax error: Encountered "derby-properties" at line 1, column 4.
> ij> -- derby-properties
> select * from t1;
> ERROR 42X01: Syntax error: Encountered "derby-properties" at line 2, column 4.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
