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Merge pull request #16935 from ucasFL/agg-func-setting-null-for-empty

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`aggregate_functions_null_for_empty` move OrNull ahead
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Kruglov Pavel 2020-12-11 17:11:39 +03:00 committed by GitHub
commit a8c1d17f83
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3 changed files with 109 additions and 1 deletions
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54
src/Interpreters/TreeRewriter.cpp
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@ -125,12 +125,60 @@ struct CustomizeAggregateFunctionsSuffixData
{
auto properties = instance.tryGetProperties(func.name);
if (properties && !properties->returns_default_when_only_null)
func.name = func.name + customized_func_suffix;
{
func.name += customized_func_suffix;
}
}
}
};
// Used to rewrite aggregate functions with -OrNull suffix in some cases, such as sumIfOrNull, we shoule rewrite to sumOrNullIf
struct CustomizeAggregateFunctionsMoveSuffixData
{
using TypeToVisit = ASTFunction;
const String & customized_func_suffix;
String moveSuffixAhead(const String & name) const
{
auto prefix = name.substr(0, name.size() - customized_func_suffix.size());
auto prefix_size = prefix.size();
if (endsWith(prefix, "MergeState"))
return prefix.substr(0, prefix_size - 10) + customized_func_suffix + "MergeState";
if (endsWith(prefix, "Merge"))
return prefix.substr(0, prefix_size - 5) + customized_func_suffix + "Merge";
if (endsWith(prefix, "State"))
return prefix.substr(0, prefix_size - 5) + customized_func_suffix + "State";
if (endsWith(prefix, "If"))
return prefix.substr(0, prefix_size - 2) + customized_func_suffix + "If";
return name;
}
void visit(ASTFunction & func, ASTPtr &) const
{
const auto & instance = AggregateFunctionFactory::instance();
if (instance.isAggregateFunctionName(func.name))
{
if (endsWith(func.name, customized_func_suffix))
{
auto properties = instance.tryGetProperties(func.name);
if (properties && !properties->returns_default_when_only_null)
{
func.name = moveSuffixAhead(func.name);
}
}
}
}
};
using CustomizeAggregateFunctionsOrNullVisitor = InDepthNodeVisitor<OneTypeMatcher<CustomizeAggregateFunctionsSuffixData>, true>;
using CustomizeAggregateFunctionsMoveOrNullVisitor = InDepthNodeVisitor<OneTypeMatcher<CustomizeAggregateFunctionsMoveSuffixData>, true>;
/// Translate qualified names such as db.table.column, table.column, table_alias.column to names' normal form.
/// Expand asterisks and qualified asterisks with column names.
@ -753,6 +801,10 @@ void TreeRewriter::normalize(ASTPtr & query, Aliases & aliases, const Settings &
CustomizeAggregateFunctionsOrNullVisitor(data_or_null).visit(query);
}
/// Move -OrNull suffix ahead, this should execute after add -OrNull suffix
CustomizeAggregateFunctionsMoveOrNullVisitor::Data data_or_null{"OrNull"};
CustomizeAggregateFunctionsMoveOrNullVisitor(data_or_null).visit(query);
/// Creates a dictionary `aliases`: alias -> ASTPtr
QueryAliasesVisitor(aliases).visit(query);

20
tests/queries/0_stateless/01562_agg_null_for_empty_ahead.reference Normal file
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@ -0,0 +1,20 @@
0
0
0
0
0
1
\N
\N
1
\N
\N
0
\N
0
\N
1
\N
\N
1
\N

36
tests/queries/0_stateless/01562_agg_null_for_empty_ahead.sql Normal file
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@ -0,0 +1,36 @@
SELECT sumMerge(s) FROM (SELECT sumState(number) s FROM numbers(0));
SELECT sumMerge(s) FROM (SELECT sumState(number) s FROM numbers(1));
SELECT sumMerge(s) FROM (SELECT sumMergeState(n) s FROM (SELECT sumState(number) n FROM numbers(0)));
SELECT sumMerge(s) FROM (SELECT sumMergeState(n) s FROM (SELECT sumState(number) n FROM numbers(1)));
SELECT sumIf(1, 0);
SELECT sumIf(1, 1);
-- should return Null even if we donn't set aggregate_functions_null_for_empty
SELECT sumIfOrNull(1, 0);
SELECT sumOrNullIf(1, 0);
SELECT nullIf(1, 0);
SELECT nullIf(1, 1);
SET aggregate_functions_null_for_empty=1;
SELECT sumMerge(s) FROM (SELECT sumState(number) s FROM numbers(0));
SELECT sumMerge(s) FROM (SELECT sumState(number) s FROM numbers(1));
SELECT sumMerge(s) FROM (SELECT sumMergeState(n) s FROM (SELECT sumState(number) n FROM numbers(0)));
SELECT sumMerge(s) FROM (SELECT sumMergeState(n) s FROM (SELECT sumState(number) n FROM numbers(1)));
SELECT sumIf(1, 0);
SELECT sumIf(1, 1);
SELECT sumIfOrNull(1, 0);
SELECT sumOrNullIf(1, 0);
SELECT nullIf(1, 0);
SELECT nullIf(1, 1);