Commit 33c4431d authored by mhansson/martin@linux-st28.site's avatar mhansson/martin@linux-st28.site
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Bug #32858: Erro: "Incorrect usage of UNION and INTO" does not take 

subselects into account

It is forbidden to use the SELECT INTO construction inside UNION statements
unless on the last SELECT of the union. The parser records whether it 
has seen INTO or not when parsing a UNION statement. But if the INTO was
legally used in an outer query, an error is thrown if UNION is seen in a
subquery. Fixed in 5.0 by remembering the nesting level of INTO tokens and 
mitigate the error unless it collides with the UNION.
parent 7f67efcc

mysql-test/r/union.result

+42 −0
Original line number Diff line number Diff line
@@ -1389,4 +1389,46 @@ select @var; 
1

(select 2) union (select 1 into @var);

ERROR 42000: Result consisted of more than one row

CREATE TABLE t1 (a INT);

INSERT INTO t1 VALUES (1);

SELECT a INTO @v FROM (

SELECT a FROM t1

UNION

SELECT a FROM t1

) alias;

SELECT a INTO OUTFILE 'union.out.file' FROM (

SELECT a FROM t1

UNION

SELECT a FROM t1 WHERE 0

) alias;

SELECT a INTO DUMPFILE 'union.out.file2' FROM (

SELECT a FROM t1

UNION

SELECT a FROM t1 WHERE 0

) alias;

SELECT a FROM (

SELECT a FROM t1

UNION

SELECT a INTO @v FROM t1

) alias;

SELECT a FROM (

SELECT a FROM t1

UNION

SELECT a INTO OUTFILE 'union.out.file3' FROM t1

) alias;

SELECT a FROM (

SELECT a FROM t1

UNION

SELECT a INTO DUMPFILE 'union.out.file4' FROM t1

) alias;

SELECT a FROM t1 UNION SELECT a INTO @v FROM t1;

SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file5' FROM t1;

SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file6' FROM t1;

SELECT a INTO @v FROM t1 UNION SELECT a FROM t1;

ERROR HY000: Incorrect usage of UNION and INTO

SELECT a INTO OUTFILE 'union.out.file7' FROM t1 UNION SELECT a FROM t1;

ERROR HY000: Incorrect usage of UNION and INTO

SELECT a INTO DUMPFILE 'union.out.file8' FROM t1 UNION SELECT a FROM t1;

ERROR HY000: Incorrect usage of UNION and INTO

DROP TABLE t1;

End of 5.0 tests

mysql-test/t/union.test

+59 −0
Original line number Diff line number Diff line
@@ -877,4 +877,63 @@ DROP TABLE t1; 
select @var;

--error 1172

(select 2) union (select 1 into @var);



#

# Bug#32858: Erro: "Incorrect usage of UNION and INTO" does not take subselects 

# into account

#

CREATE TABLE t1 (a INT);

INSERT INTO t1 VALUES (1);



SELECT a INTO @v FROM (

  SELECT a FROM t1

  UNION

  SELECT a FROM t1

) alias;



SELECT a INTO OUTFILE 'union.out.file' FROM (

  SELECT a FROM t1

  UNION

  SELECT a FROM t1 WHERE 0

) alias;



SELECT a INTO DUMPFILE 'union.out.file2' FROM (

  SELECT a FROM t1

  UNION

  SELECT a FROM t1 WHERE 0

) alias;



#

# INTO will not be allowed in subqueries in version 5.1 and above.

#

SELECT a FROM (

  SELECT a FROM t1

  UNION

  SELECT a INTO @v FROM t1

) alias;



SELECT a FROM (

  SELECT a FROM t1

  UNION

  SELECT a INTO OUTFILE 'union.out.file3' FROM t1

) alias;



SELECT a FROM (

  SELECT a FROM t1

  UNION

  SELECT a INTO DUMPFILE 'union.out.file4' FROM t1

) alias;



SELECT a FROM t1 UNION SELECT a INTO @v FROM t1;

SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file5' FROM t1;

SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file6' FROM t1;

--error ER_WRONG_USAGE

SELECT a INTO @v FROM t1 UNION SELECT a FROM t1;

--error ER_WRONG_USAGE

SELECT a INTO OUTFILE 'union.out.file7' FROM t1 UNION SELECT a FROM t1;

--error ER_WRONG_USAGE

SELECT a INTO DUMPFILE 'union.out.file8' FROM t1 UNION SELECT a FROM t1;



DROP TABLE t1;



--echo End of 5.0 tests

sql/sql_class.cc

+1 −0
Original line number Diff line number Diff line
@@ -931,6 +931,7 @@ void THD::rollback_item_tree_changes() 
select_result::select_result()

{

  thd=current_thd;

  nest_level= -1;

}



void select_result::send_error(uint errcode,const char *err)

sql/sql_class.h

+34 −3
Original line number Diff line number Diff line
@@ -1891,6 +1891,7 @@ class select_result :public Sql_alloc { 
protected:

  THD *thd;

  SELECT_LEX_UNIT *unit;

  uint nest_level;

public:

  select_result();

  virtual ~select_result() {};
@@ -1927,6 +1928,12 @@ class select_result :public Sql_alloc { 
  */

  virtual void cleanup();

  void set_thd(THD *thd_arg) { thd= thd_arg; }

  /**

     The nest level, if supported. 

     @return

     -1 if nest level is undefined, otherwise a positive integer.

   */

  int get_nest_level() { return nest_level; }

#ifdef EMBEDDED_LIBRARY

  virtual void begin_dataset() {}

#else
@@ -2006,7 +2013,14 @@ class select_export :public select_to_file { 
  bool is_unsafe_field_sep;

  bool fixed_row_size;

public:

  select_export(sql_exchange *ex) :select_to_file(ex) {}

  /**

     Creates a select_export to represent INTO OUTFILE <filename> with a

     defined level of subquery nesting.

   */

  select_export(sql_exchange *ex, uint nest_level_arg) :select_to_file(ex) 

  {

    nest_level= nest_level_arg;

  }

  ~select_export();

  int prepare(List<Item> &list, SELECT_LEX_UNIT *u);

  bool send_data(List<Item> &items);
@@ -2015,7 +2029,15 @@ class select_export :public select_to_file { 


class select_dump :public select_to_file {

public:

  select_dump(sql_exchange *ex) :select_to_file(ex) {}

  /**

     Creates a select_export to represent INTO DUMPFILE <filename> with a

     defined level of subquery nesting.

   */  

  select_dump(sql_exchange *ex, uint nest_level_arg) : 

    select_to_file(ex) 

  {

    nest_level= nest_level_arg;

  }

  int prepare(List<Item> &list, SELECT_LEX_UNIT *u);

  bool send_data(List<Item> &items);

};
@@ -2422,7 +2444,16 @@ class select_dumpvar :public select_result_interceptor { 
  ha_rows row_count;

public:

  List<my_var> var_list;

  select_dumpvar()  { var_list.empty(); row_count= 0;}

  /**

     Creates a select_dumpvar to represent INTO <variable> with a defined 

     level of subquery nesting.

   */

  select_dumpvar(uint nest_level_arg)

  {

    var_list.empty();

    row_count= 0;

    nest_level= nest_level_arg;

  }

  ~select_dumpvar() {}

  int prepare(List<Item> &list, SELECT_LEX_UNIT *u);

  bool send_data(List<Item> &items);

sql/sql_yacc.yy

+16 −9
Original line number Diff line number Diff line
@@ -6356,7 +6356,8 @@ procedure_item: 
select_var_list_init:

	   {

             LEX *lex=Lex;

	     if (!lex->describe && (!(lex->result= new select_dumpvar())))

	     if (!lex->describe && 

                 (!(lex->result= new select_dumpvar(lex->nest_level))))

	        MYSQL_YYABORT;

	   }

	   select_var_list
@@ -6430,7 +6431,7 @@ into_destination: 
          LEX *lex= Lex;

          lex->uncacheable(UNCACHEABLE_SIDEEFFECT);

          if (!(lex->exchange= new sql_exchange($2.str, 0)) ||

              !(lex->result= new select_export(lex->exchange)))

              !(lex->result= new select_export(lex->exchange, lex->nest_level)))

            MYSQL_YYABORT;

	}

	opt_field_term opt_line_term
@@ -6442,7 +6443,7 @@ into_destination: 
	    lex->uncacheable(UNCACHEABLE_SIDEEFFECT);

	    if (!(lex->exchange= new sql_exchange($2.str,1)))

	      MYSQL_YYABORT;

	    if (!(lex->result= new select_dump(lex->exchange)))

	    if (!(lex->result= new select_dump(lex->exchange, lex->nest_level)))

	      MYSQL_YYABORT;

	  }

	}
@@ -9421,9 +9422,15 @@ union_list: 
	UNION_SYM union_option

	{

	  LEX *lex=Lex;

	  if (lex->result)

	  if (lex->result && 

              (lex->result->get_nest_level() == -1 ||

               lex->result->get_nest_level() == lex->nest_level))

          {

	    /* Only the last SELECT can have  INTO...... */

            /* 

               Only the last SELECT can have INTO unless the INTO and UNION

               are at different nest levels. In version 5.1 and above, INTO

               will onle be allowed at top level.

            */

            my_error(ER_WRONG_USAGE, MYF(0), "UNION", "INTO");

            MYSQL_YYABORT;

          }