Bug #6139 UNION doesn't understand collate in the column of second select (1412365a) · Commits · Software / OSDI20 Artifacts / mariadb

mysql-test/r/union.result

+78 −0

Original line number	Diff line number	Diff line
		@@ -1033,3 +1033,81 @@ a
		No
		aaa,bbb
		drop table t1,t2,t3,t4;
		create table t1 as
		(select _latin1'test') union
		(select _latin1'TEST') union
		(select _latin1'TeST');
		show create table t1;
		Table Create Table
		t1 CREATE TABLE `t1` (
		`test` char(4) NOT NULL default ''
		) ENGINE=MyISAM DEFAULT CHARSET=latin1
		select count(*) from t1;
		count(*)
		1
		drop table t1;
		create table t1 as
		(select _latin1'test' collate latin1_bin) union
		(select _latin1'TEST') union
		(select _latin1'TeST');
		show create table t1;
		Table Create Table
		t1 CREATE TABLE `t1` (
		`_latin1'test' collate latin1_bin` char(4) character set latin1 collate latin1_bin NOT NULL default ''
		) ENGINE=MyISAM DEFAULT CHARSET=latin1
		select count(*) from t1;
		count(*)
		3
		drop table t1;
		create table t1 as
		(select _latin1'test') union
		(select _latin1'TEST' collate latin1_bin) union
		(select _latin1'TeST');
		show create table t1;
		Table Create Table
		t1 CREATE TABLE `t1` (
		`test` char(4) character set latin1 collate latin1_bin NOT NULL default ''
		) ENGINE=MyISAM DEFAULT CHARSET=latin1
		select count(*) from t1;
		count(*)
		3
		drop table t1;
		create table t1 as
		(select _latin1'test') union
		(select _latin1'TEST') union
		(select _latin1'TeST' collate latin1_bin);
		show create table t1;
		Table Create Table
		t1 CREATE TABLE `t1` (
		`test` char(4) character set latin1 collate latin1_bin NOT NULL default ''
		) ENGINE=MyISAM DEFAULT CHARSET=latin1
		select count(*) from t1;
		count(*)
		3
		drop table t1;
		create table t2 (
		a char character set latin1 collate latin1_swedish_ci,
		b char character set latin1 collate latin1_bin);
		create table t1 as
		(select a from t2) union
		(select b from t2);
		ERROR HY000: Illegal mix of collations for operation 'UNION'
		create table t1 as
		(select a collate latin1_german1_ci from t2) union
		(select b from t2);
		show create table t1;
		Table Create Table
		t1 CREATE TABLE `t1` (
		`a collate latin1_german1_ci` char(1) character set latin1 collate latin1_german1_ci default NULL
		) ENGINE=MyISAM DEFAULT CHARSET=latin1
		drop table t1;
		create table t1 as
		(select a from t2) union
		(select b collate latin1_german1_ci from t2);
		show create table t1;
		Table Create Table
		t1 CREATE TABLE `t1` (
		`a` char(1) character set latin1 collate latin1_german1_ci default NULL
		) ENGINE=MyISAM DEFAULT CHARSET=latin1
		drop table t1;
		drop table t2;

mysql-test/t/union.test

+55 −0

Original line number	Diff line number	Diff line
		@@ -595,3 +595,58 @@ select a as a from t3 union select "1";
		select a as a from t4 union select a from t3;
		select a as a from t1 union select a from t4;
		drop table t1,t2,t3,t4;

		#
		# Bug #6139 UNION doesn't understand collate in the column of second select
		#
		create table t1 as
		(select _latin1'test') union
		(select _latin1'TEST') union
		(select _latin1'TeST');
		show create table t1;
		select count(*) from t1;
		drop table t1;

		create table t1 as
		(select _latin1'test' collate latin1_bin) union
		(select _latin1'TEST') union
		(select _latin1'TeST');
		show create table t1;
		select count(*) from t1;
		drop table t1;

		create table t1 as
		(select _latin1'test') union
		(select _latin1'TEST' collate latin1_bin) union
		(select _latin1'TeST');
		show create table t1;
		select count(*) from t1;
		drop table t1;

		create table t1 as
		(select _latin1'test') union
		(select _latin1'TEST') union
		(select _latin1'TeST' collate latin1_bin);
		show create table t1;
		select count(*) from t1;
		drop table t1;

		create table t2 (
		a char character set latin1 collate latin1_swedish_ci,
		b char character set latin1 collate latin1_bin);
		--error 1271
		create table t1 as
		(select a from t2) union
		(select b from t2);
		create table t1 as
		(select a collate latin1_german1_ci from t2) union
		(select b from t2);
		show create table t1;
		drop table t1;
		create table t1 as
		(select a from t2) union
		(select b collate latin1_german1_ci from t2);
		show create table t1;
		drop table t1;
		drop table t2;

sql/item.cc

+2 −2

Original line number	Diff line number	Diff line
		@@ -2559,7 +2559,7 @@ bool Item_type_holder::join_types(THD thd, Item item)
		(new_result_type != item_type) \|\| (new_length > max_length) \|\|
		(!maybe_null && item->maybe_null) \|\|
		(item_type == STRING_RESULT &&
		!my_charset_same(collation.collation, item->collation.collation)))
		collation.collation != item->collation.collation))
		{
		if (use_expression_type \|\| item->type() != Item::FIELD_ITEM)
		field_example= 0;

sql/sql_union.cc

+17 −0

Original line number	Diff line number	Diff line
		@@ -264,6 +264,23 @@ int st_select_lex_unit::prepare(THD thd_arg, select_result sel_result,
		}
		}

		{
		/*
		Check that it was possible to aggregate all collations together.
		*/
		List_iterator_fast<Item> tp(types);
		Item *type;
		while ((type= tp++))
		{
		if (type->result_type() == STRING_RESULT &&
		type->collation.derivation == DERIVATION_NONE)
		{
		my_error(ER_CANT_AGGREGATE_NCOLLATIONS, MYF(0), "UNION");
		goto err;
		}
		}
		}

		// it is not single select
		if (first_select->next_select())
		{