From 3177e8ebc49d95bb9c7768e5fc6aceb66bbb1783 Mon Sep 17 00:00:00 2001 From: unknown Date: Tue, 10 Oct 2006 17:08:47 +0400 Subject: [PATCH] BUG#21354: (COUNT(*) = 1) not working in SELECT inside prepared statement. The problem was that during statement re-execution if the result was empty the old result could be returned for group functions. The solution is to implement proper cleanup() method in group functions. mysql-test/r/ps.result: Add result for bug#21354: (COUNT(*) = 1) not working in SELECT inside prepared statement. mysql-test/t/func_gconcat.test: Add a comment that the test case is from bug#836. mysql-test/t/ps.test: Add test case for bug#21354: (COUNT(*) = 1) not working in SELECT inside prepared statement. sql/item_sum.cc: Call clear() in Item_sum_count::cleanup(). sql/item_sum.h: Add comments. Add proper cleanup() methods. Change Item_sum::no_rows_in_result() to call clear() instead of reset(), as the latter also issues add(), and there is nothing to add when there are no rows in result. --- mysql-test/r/ps.result | 97 ++++++++++++++++++++++++++++++++++ mysql-test/t/func_gconcat.test | 2 +- mysql-test/t/ps.test | 74 +++++++++++++++++++++++++- sql/item_sum.cc | 1 + sql/item_sum.h | 48 ++++++++++++++++- 5 files changed, 219 insertions(+), 3 deletions(-) diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result index 01aa4ddf859..82d8ba275b6 100644 --- a/mysql-test/r/ps.result +++ b/mysql-test/r/ps.result @@ -889,3 +889,100 @@ create temporary table if not exists t1 (a1 int); execute stmt; drop temporary table t1; deallocate prepare stmt; +DROP TABLE IF EXISTS t1; +CREATE TABLE t1 (i INT, INDEX(i)); +INSERT INTO t1 VALUES (1); +PREPARE stmt FROM "SELECT (COUNT(i) = 1), COUNT(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +(COUNT(i) = 1) COUNT(i) +0 0 +SET @a = 1; +EXECUTE stmt USING @a; +(COUNT(i) = 1) COUNT(i) +1 1 +SET @a = 0; +EXECUTE stmt USING @a; +(COUNT(i) = 1) COUNT(i) +0 0 +PREPARE stmt FROM "SELECT (AVG(i) = 1), AVG(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +(AVG(i) = 1) AVG(i) +NULL NULL +SET @a = 1; +EXECUTE stmt USING @a; +(AVG(i) = 1) AVG(i) +1 1.0000 +SET @a = 0; +EXECUTE stmt USING @a; +(AVG(i) = 1) AVG(i) +NULL NULL +PREPARE stmt FROM "SELECT (VARIANCE(i) = 1), VARIANCE(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +(VARIANCE(i) = 1) VARIANCE(i) +NULL NULL +SET @a = 1; +EXECUTE stmt USING @a; +(VARIANCE(i) = 1) VARIANCE(i) +0 0.0000 +SET @a = 0; +EXECUTE stmt USING @a; +(VARIANCE(i) = 1) VARIANCE(i) +NULL NULL +PREPARE stmt FROM "SELECT (STDDEV(i) = 1), STDDEV(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +(STDDEV(i) = 1) STDDEV(i) +NULL NULL +SET @a = 1; +EXECUTE stmt USING @a; +(STDDEV(i) = 1) STDDEV(i) +0 0.0000 +SET @a = 0; +EXECUTE stmt USING @a; +(STDDEV(i) = 1) STDDEV(i) +NULL NULL +PREPARE stmt FROM "SELECT (BIT_OR(i) = 1), BIT_OR(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +(BIT_OR(i) = 1) BIT_OR(i) +0 0 +SET @a = 1; +EXECUTE stmt USING @a; +(BIT_OR(i) = 1) BIT_OR(i) +1 1 +SET @a = 0; +EXECUTE stmt USING @a; +(BIT_OR(i) = 1) BIT_OR(i) +0 0 +PREPARE stmt FROM "SELECT (BIT_AND(i) = 1), BIT_AND(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +(BIT_AND(i) = 1) BIT_AND(i) +0 18446744073709551615 +SET @a = 1; +EXECUTE stmt USING @a; +(BIT_AND(i) = 1) BIT_AND(i) +1 1 +SET @a = 0; +EXECUTE stmt USING @a; +(BIT_AND(i) = 1) BIT_AND(i) +0 18446744073709551615 +PREPARE stmt FROM "SELECT (BIT_XOR(i) = 1), BIT_XOR(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +(BIT_XOR(i) = 1) BIT_XOR(i) +0 0 +SET @a = 1; +EXECUTE stmt USING @a; +(BIT_XOR(i) = 1) BIT_XOR(i) +1 1 +SET @a = 0; +EXECUTE stmt USING @a; +(BIT_XOR(i) = 1) BIT_XOR(i) +0 0 +DEALLOCATE PREPARE stmt; +DROP TABLE t1; +End of 4.1 tests. diff --git a/mysql-test/t/func_gconcat.test b/mysql-test/t/func_gconcat.test index 8f50690dd8b..21ec7362877 100644 --- a/mysql-test/t/func_gconcat.test +++ b/mysql-test/t/func_gconcat.test @@ -99,7 +99,7 @@ select ifnull(group_concat(concat(t1.id, ':', t1.name)), 'shortname') as 'withou select distinct ifnull(group_concat(concat(t1.id, ':', t1.name)), 'shortname') as 'with distinct: cutoff at length of shortname' from t1; drop table t1; -# check zero rows +# check zero rows (bug#836) create table t1(id int); create table t2(id int); insert into t1 values(0),(1); diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test index 0ca293eb1ba..03fcc241d23 100644 --- a/mysql-test/t/ps.test +++ b/mysql-test/t/ps.test @@ -951,4 +951,76 @@ execute stmt; drop temporary table t1; deallocate prepare stmt; -# End of 4.1 tests + +# +# BUG#21354: (COUNT(*) = 1) not working in SELECT inside prepared +# statement +# +--disable_warnings +DROP TABLE IF EXISTS t1; +--enable_warnings + +CREATE TABLE t1 (i INT, INDEX(i)); +INSERT INTO t1 VALUES (1); + +PREPARE stmt FROM "SELECT (COUNT(i) = 1), COUNT(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +SET @a = 1; +EXECUTE stmt USING @a; +SET @a = 0; +EXECUTE stmt USING @a; + +PREPARE stmt FROM "SELECT (AVG(i) = 1), AVG(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +SET @a = 1; +EXECUTE stmt USING @a; +SET @a = 0; +EXECUTE stmt USING @a; + +PREPARE stmt FROM "SELECT (VARIANCE(i) = 1), VARIANCE(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +SET @a = 1; +EXECUTE stmt USING @a; +SET @a = 0; +EXECUTE stmt USING @a; + +PREPARE stmt FROM "SELECT (STDDEV(i) = 1), STDDEV(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +SET @a = 1; +EXECUTE stmt USING @a; +SET @a = 0; +EXECUTE stmt USING @a; + +PREPARE stmt FROM "SELECT (BIT_OR(i) = 1), BIT_OR(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +SET @a = 1; +EXECUTE stmt USING @a; +SET @a = 0; +EXECUTE stmt USING @a; + +PREPARE stmt FROM "SELECT (BIT_AND(i) = 1), BIT_AND(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +SET @a = 1; +EXECUTE stmt USING @a; +SET @a = 0; +EXECUTE stmt USING @a; + +PREPARE stmt FROM "SELECT (BIT_XOR(i) = 1), BIT_XOR(i) FROM t1 WHERE i = ?"; +SET @a = 0; +EXECUTE stmt USING @a; +SET @a = 1; +EXECUTE stmt USING @a; +SET @a = 0; +EXECUTE stmt USING @a; + +DEALLOCATE PREPARE stmt; +DROP TABLE t1; + + +--echo End of 4.1 tests. diff --git a/sql/item_sum.cc b/sql/item_sum.cc index 0b9b10d05d4..e480cb031d8 100644 --- a/sql/item_sum.cc +++ b/sql/item_sum.cc @@ -312,6 +312,7 @@ longlong Item_sum_count::val_int() void Item_sum_count::cleanup() { DBUG_ENTER("Item_sum_count::cleanup"); + clear(); Item_sum_int::cleanup(); used_table_cache= ~(table_map) 0; DBUG_VOID_RETURN; diff --git a/sql/item_sum.h b/sql/item_sum.h index 0cc2a20faa3..ea0863fc41c 100644 --- a/sql/item_sum.h +++ b/sql/item_sum.h @@ -58,9 +58,30 @@ public: Item_sum(THD *thd, Item_sum *item); enum Type type() const { return SUM_FUNC_ITEM; } virtual enum Sumfunctype sum_func () const=0; + + /* + This method is similar to add(), but it is called when the current + aggregation group changes. Thus it performs a combination of + clear() and add(). + */ inline bool reset() { clear(); return add(); }; + + /* + Prepare this item for evaluation of an aggregate value. This is + called by reset() when a group changes, or, for correlated + subqueries, between subquery executions. E.g. for COUNT(), this + method should set count= 0; + */ virtual void clear()= 0; + + /* + This method is called for the next row in the same group. Its + purpose is to aggregate the new value to the previous values in + the group (i.e. since clear() was called last time). For example, + for COUNT(), do count++. + */ virtual bool add()=0; + /* Called when new group is started and results are being saved in a temporary table. Similar to reset(), but must also store value in @@ -86,7 +107,17 @@ public: void make_field(Send_field *field); void print(String *str); void fix_num_length_and_dec(); - void no_rows_in_result() { reset(); } + + /* + This function is called by the execution engine to assign 'NO ROWS + FOUND' value to an aggregate item, when the underlying result set + has no rows. Such value, in a general case, may be different from + the default value of the item after 'clear()': e.g. a numeric item + may be initialized to 0 by clear() and to NULL by + no_rows_in_result(). + */ + void no_rows_in_result() { clear(); } + virtual bool setup(THD *thd) {return 0;} virtual void make_unique() {} Item *get_tmp_table_item(THD *thd); @@ -304,6 +335,11 @@ class Item_sum_avg :public Item_sum_num void no_rows_in_result() {} const char *func_name() const { return "avg"; } Item *copy_or_same(THD* thd); + void cleanup() + { + clear(); + Item_sum_num::cleanup(); + } }; class Item_sum_variance; @@ -361,6 +397,11 @@ class Item_sum_variance : public Item_sum_num void no_rows_in_result() {} const char *func_name() const { return "variance"; } Item *copy_or_same(THD* thd); + void cleanup() + { + clear(); + Item_sum_num::cleanup(); + } }; class Item_sum_std; @@ -485,6 +526,11 @@ public: void update_field(); void fix_length_and_dec() { decimals=0; max_length=21; unsigned_flag=1; maybe_null=null_value=0; } + void cleanup() + { + clear(); + Item_sum_int::cleanup(); + } };