Re: bk commit into 5.0 tree (mhansson:1.2502) BUG#30234

[Marc Alff]

Hi Martin


mhansson@stripped wrote:
> Below is the list of changes that have just been committed into a local
> 5.0 repository of martin. When martin does a push these changes will
> be propagated to the main repository and, within 24 hours after the
> push, to the public repository.
> For information on how to access the public repository
> see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html
>
> ChangeSet@stripped, 2007-08-24 15:40:16+02:00, mhansson@stripped +4 -0
>   Bug #30234: Unexpected behavior using DELETE with AS and USING
>   
>   DELETE FROM ... USING ... statements with the following type of 
>   ambiguous aliasing gave unexpected results:
>   DELETE FROM t1 AS alias USING t1, t2 AS alias WHERE t1.a = alias.a;
>   This query would leave table t1 intact but delete rows from t2.
>   Fixed by changing DELETE FROM ... USING syntax so that only alias 
>   references (as opposed to alias declarations) may be used in FROM.
>
>   BitKeeper/etc/ignore@stripped, 2007-08-24 15:40:14+02:00, mhansson@stripped +5
> -0
>     Added support-files/mysqld_multi.server tests/bug25714 cscope.in.out cscope.out
> cscope.po.out to the ignore list
>
>   mysql-test/r/delete.result@stripped, 2007-08-24 15:40:14+02:00,
> mhansson@stripped +37 -0
>     Bug#30234: Test Result
>
>   mysql-test/t/delete.test@stripped, 2007-08-24 15:40:14+02:00, mhansson@stripped
> +44 -0
>     Bug#30234: Test Case
>
>   sql/sql_yacc.yy@stripped, 2007-08-24 15:40:14+02:00, mhansson@stripped +17 -2
>     Bug#30234:
>     - Added parser rule table_alias_ref_list that contains a list of table 
>       aliases only.
>     - Added parser rule table_alias_ref that sets the TL_OPTION_ALIAS in 
>       order to turn off semantic checking that applies only for table names.
>
>   
(...)

> diff -Nrup a/sql/sql_yacc.yy b/sql/sql_yacc.yy
> --- a/sql/sql_yacc.yy	2007-07-30 01:33:07 +02:00
> +++ b/sql/sql_yacc.yy	2007-08-24 15:40:14 +02:00
> @@ -1159,7 +1159,8 @@ bool my_yyoverflow(short **a, YYSTYPE **
>  	field_opt_list opt_binary table_lock_list table_lock
>  	ref_list opt_on_delete opt_on_delete_list opt_on_delete_item use
>  	opt_delete_options opt_delete_option varchar nchar nvarchar
> -	opt_outer table_list table_name opt_option opt_place
> +	opt_outer table_list table_name table_alias_ref_list table_alias_ref
> +	opt_option opt_place
>  	opt_attribute opt_attribute_list attribute column_list column_list_id
>  	opt_column_list grant_privileges grant_ident grant_list grant_option
>  	object_privilege object_privilege_list user_list rename_list
> @@ -6504,6 +6505,20 @@ table_name:
>  	}
>  	;
>  
> +table_alias_ref_list:
> +        table_alias_ref
> +        | table_alias_ref_list ',' table_alias_ref;
> +
>   
Left recursive, ok.

> +table_alias_ref:
> +	table_ident
> +	{
> +	  if (!Select->add_table_to_list(YYTHD, $1, NULL,
> +                                         TL_OPTION_UPDATING | TL_OPTION_ALIAS,
> +                                         Lex->lock_option ))
> +	    MYSQL_YYABORT;
> +	}
> +	;
>   
Ok
> +
>  if_exists:
>  	/* empty */ { $$= 0; }
>  	| IF EXISTS { $$= 1; }
> @@ -6774,7 +6789,7 @@ single_multi:
>              if (multi_delete_set_locks_and_link_aux_tables(Lex))
>                MYSQL_YYABORT;
>            }
> -	| FROM table_wild_list
> +	| FROM table_alias_ref_list
>   
Ok.

Verified by analysis of the grammar that this change impact only the
following syntax :

DELETE ... FROM ... USING

Other statements using table aliases are not affected.

>  	  { mysql_init_multi_delete(Lex); }
>  	  USING join_table_list where_clause
>            { 
>
>   
Ok to push

Thanks,
Marc