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dbms: function 'transform': added support for constant argument [#METR-15987].

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This commit is contained in:
Alexey Milovidov 2015-04-29 04:30:44 +03:00
parent 738e736500
commit 685aa695bb
3 changed files with 48 additions and 13 deletions
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53
dbms/include/DB/Functions/FunctionsMiscellaneous.h
View File

@ -1003,6 +1003,13 @@ public:
prepare(array_from->getData(), array_to->getData(), block, arguments);
const auto in = block.getByPosition(arguments.front()).column.get();
if (in->isConst())
{
executeConst(block, arguments, result);
return;
}
auto column_result = block.getByPosition(result).type->createColumn();
auto out = column_result.get();
@ -1024,6 +1031,34 @@ public:
block.getByPosition(result).column = column_result;
}
private:
void executeConst(Block & block, const ColumnNumbers & arguments, const size_t result)
{
/// Составим блок из полноценных столбцов размера 1 и вычислим функцию как обычно.
Block tmp_block;
ColumnNumbers tmp_arguments;
tmp_block.insert(block.getByPosition(arguments[0]));
tmp_block.getByPosition(0).column = static_cast<IColumnConst *>(tmp_block.getByPosition(0).column->cloneResized(1).get())->convertToFullColumn();
tmp_arguments.push_back(0);
for (size_t i = 1; i < arguments.size(); ++i)
{
tmp_block.insert(block.getByPosition(arguments[i]));
tmp_arguments.push_back(i);
}
tmp_block.insert(block.getByPosition(result));
size_t tmp_result = arguments.size();
execute(tmp_block, tmp_arguments, tmp_result);
block.getByPosition(result).column = block.getByPosition(result).type->createConstColumn(
block.rowsInFirstColumn(),
(*tmp_block.getByPosition(tmp_result).column)[0]);
}
template <typename T>
bool executeNum(const IColumn * in_untyped, IColumn * out_untyped)
{
@ -1060,12 +1095,6 @@ public:
return true;
}
else if (const auto in = typeid_cast<const ColumnConst<T> *>(in_untyped))
{
/* TODO */
return true;
}
return false;
}
@ -1091,12 +1120,6 @@ public:
return true;
}
else if (const auto in = typeid_cast<const ColumnConstString *>(in_untyped))
{
/* TODO */
return true;
}
return false;
}
@ -1252,7 +1275,7 @@ public:
}
}
private:
/// Разные варианты хэш-таблиц для реализации отображения.
using NumToNum = HashMap<UInt64, UInt64, HashCRC32<UInt64>>;
@ -1298,6 +1321,10 @@ private:
if (arguments.size() == 4)
{
const IColumnConst * default_col = dynamic_cast<const IColumnConst *>(&*block.getByPosition(arguments[3]).column);
if (!default_col)
throw Exception("Fourth argument of function " + getName() + " (default value) must be constant", ErrorCodes::ILLEGAL_COLUMN);
default_value = (*default_col)[0];
/// Нужно ли преобразовать элементы to и default_value к наименьшему общему типу, который является Float64?

4
dbms/tests/queries/0_stateless/00153_transform.reference
View File

@ -98,3 +98,7 @@ abc
333
1
1
Остальные
Яндекс
Google
Остальные

4
dbms/tests/queries/0_stateless/00153_transform.sql
View File

@ -8,3 +8,7 @@ SELECT transform(toString(number), ['3', '5', '7'], [111, 222, 333], 0) FROM sys
SELECT transform(toString(number), ['3', '5', '7'], [111, 222, 333], -1) FROM system.numbers LIMIT 10;
SELECT transform(toString(number), ['3', '5', '7'], [111, 222, 333], -1.1) FROM system.numbers LIMIT 10;
SELECT transform(toString(number), ['3', '5', '7'], [111, 222.2, 333], 1) FROM system.numbers LIMIT 10;
SELECT transform(1, [2, 3], ['Яндекс', 'Google'], 'Остальные') AS title;
SELECT transform(2, [2, 3], ['Яндекс', 'Google'], 'Остальные') AS title;
SELECT transform(3, [2, 3], ['Яндекс', 'Google'], 'Остальные') AS title;
SELECT transform(4, [2, 3], ['Яндекс', 'Google'], 'Остальные') AS title;