diff options
Diffstat (limited to 'sql/item_sum.cc')
| -rw-r--r-- | sql/item_sum.cc | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/sql/item_sum.cc b/sql/item_sum.cc index 72e0e637d38..3bd00ee828d 100644 --- a/sql/item_sum.cc +++ b/sql/item_sum.cc @@ -719,6 +719,14 @@ static int simple_raw_key_cmp(void* arg, const void* key1, const void* key2) } +static int item_sum_distinct_walk_for_count(void *element, + element_count num_of_dups, + void *item) +{ + return ((Aggregator_distinct*) (item))->unique_walk_function_for_count(element); +} + + static int item_sum_distinct_walk(void *element, element_count num_of_dups, void *item) { @@ -1089,7 +1097,12 @@ void Aggregator_distinct::endup() { /* go over the tree of distinct keys and calculate the aggregate value */ use_distinct_values= TRUE; - tree->walk(table, item_sum_distinct_walk, (void*) this); + tree_walk_action func; + if (item_sum->sum_func() == Item_sum::COUNT_DISTINCT_FUNC) + func= item_sum_distinct_walk_for_count; + else + func= item_sum_distinct_walk; + tree->walk(table, func, (void*) this); use_distinct_values= FALSE; } /* prevent consecutive recalculations */ @@ -1466,6 +1479,22 @@ bool Aggregator_distinct::unique_walk_function(void *element) } +/* + A variant of unique_walk_function() that is to be used with Item_sum_count. + + COUNT is a special aggregate function: it doesn't need the values, it only + needs to count them. COUNT needs to know the values are not NULLs, but NULL + values are not put into the Unique, so we don't need to check for NULLs here. +*/ + +bool Aggregator_distinct::unique_walk_function_for_count(void *element) +{ + Item_sum_count *sum= (Item_sum_count *)item_sum; + sum->count++; + return 0; +} + + Aggregator_distinct::~Aggregator_distinct() { if (tree) |