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clickhouse: fixed some alias issues [#CONV-2944].

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This commit is contained in:
Michael Kolupaev 2013-02-11 17:30:09 +00:00
parent bebe6932fd
commit eac9f3c337
2 changed files with 57 additions and 14 deletions
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3
dbms/include/DB/Core/ErrorCodes.h
View File

@ -184,7 +184,8 @@ namespace ErrorCodes
NEGATIVE_REFCOUNT,
CHUNK_NOT_FOUND,
DUPLICATE_CHUNK_NAME,
NO_SUCH_TABLE,
MULTIPLE_ALIASES_FOR_EXPRESSION,
MULTIPLE_EXPRESSIONS_FOR_ALIAS,
POCO_EXCEPTION = 1000,
STD_EXCEPTION,

68
dbms/src/Interpreters/Expression.cpp
View File

@ -32,6 +32,27 @@ NamesAndTypesList::const_iterator Expression::findColumn(const String & name)
}
static std::string * GetAlias(ASTPtr & ast)
{
if (ASTFunction * node = dynamic_cast<ASTFunction *>(&*ast))
{
return &node->alias;
}
else if (ASTIdentifier * node = dynamic_cast<ASTIdentifier *>(&*ast))
{
return &node->alias;
}
else if (ASTLiteral * node = dynamic_cast<ASTLiteral *>(&*ast))
{
return &node->alias;
}
else
{
return NULL;
}
}
void Expression::createAliasesDict(ASTPtr & ast)
{
/// Обход снизу-вверх. Не опускаемся в подзапросы.
@ -39,20 +60,17 @@ void Expression::createAliasesDict(ASTPtr & ast)
if (!dynamic_cast<ASTSelectQuery *>(&**it))
createAliasesDict(*it);
if (ASTFunction * node = dynamic_cast<ASTFunction *>(&*ast))
std::string * alias = GetAlias(ast);
if (alias)
{
if (!node->alias.empty())
aliases[node->alias] = ast;
}
else if (ASTIdentifier * node = dynamic_cast<ASTIdentifier *>(&*ast))
{
if (!node->alias.empty())
aliases[node->alias] = ast;
}
else if (ASTLiteral * node = dynamic_cast<ASTLiteral *>(&*ast))
{
if (!node->alias.empty())
aliases[node->alias] = ast;
if (aliases.count(*alias))
{
throw Exception("Multiple expressions with the same alias", ErrorCodes::MULTIPLE_EXPRESSIONS_FOR_ALIAS);
}
else
{
aliases[*alias] = ast;
}
}
}
@ -245,9 +263,33 @@ void Expression::glueTreeImpl(ASTPtr ast, Subtrees & subtrees)
{
String tree_id = (*it)->getTreeID();
if (subtrees.end() == subtrees.find(tree_id))
{
subtrees[tree_id] = *it;
}
else
{
/// Перед заменой поддерева запомним алиас.
std::string * alias_ptr = GetAlias(*it);
std::string initial_alias;
if (alias_ptr)
initial_alias = *alias_ptr;
*it = subtrees[tree_id];
/// Объединим два алиаса.
alias_ptr = GetAlias(*it);
if (alias_ptr)
{
if (alias_ptr->empty())
{
*alias_ptr = initial_alias;
}
else if (!initial_alias.empty())
{
throw Exception("Multiple aliases for the same expression", ErrorCodes::MULTIPLE_ALIASES_FOR_EXPRESSION);
}
}
}
}
}
}