ClickHouse/src/AggregateFunctions/parseAggregateFunctionParameters.cpp
2021-07-02 03:53:08 +03:00

94 lines
3.3 KiB
C++

#include <AggregateFunctions/parseAggregateFunctionParameters.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ExpressionListParsers.h>
#include <Parsers/parseQuery.h>
#include <Interpreters/evaluateConstantExpression.h>
namespace DB
{
struct Settings;
namespace ErrorCodes
{
extern const int BAD_ARGUMENTS;
extern const int PARAMETERS_TO_AGGREGATE_FUNCTIONS_MUST_BE_LITERALS;
}
Array getAggregateFunctionParametersArray(const ASTPtr & expression_list, const std::string & error_context, ContextPtr context)
{
const ASTs & parameters = expression_list->children;
if (parameters.empty())
throw Exception("Parameters list to aggregate functions cannot be empty", ErrorCodes::BAD_ARGUMENTS);
Array params_row(parameters.size());
for (size_t i = 0; i < parameters.size(); ++i)
{
ASTPtr literal;
try
{
literal = evaluateConstantExpressionAsLiteral(parameters[i], context);
}
catch (Exception & e)
{
if (e.code() == ErrorCodes::BAD_ARGUMENTS)
throw Exception(
ErrorCodes::PARAMETERS_TO_AGGREGATE_FUNCTIONS_MUST_BE_LITERALS,
"Parameters to aggregate functions must be literals. "
"Got parameter '{}'{}",
parameters[i]->formatForErrorMessage(),
(error_context.empty() ? "" : " (in " + error_context +")"));
throw;
}
params_row[i] = literal->as<ASTLiteral>()->value;
}
return params_row;
}
void getAggregateFunctionNameAndParametersArray(
const std::string & aggregate_function_name_with_params,
std::string & aggregate_function_name,
Array & aggregate_function_parameters,
const std::string & error_context,
ContextPtr context)
{
if (aggregate_function_name_with_params.back() != ')')
{
aggregate_function_name = aggregate_function_name_with_params;
aggregate_function_parameters = Array();
return;
}
size_t pos = aggregate_function_name_with_params.find('(');
if (pos == std::string::npos || pos + 2 >= aggregate_function_name_with_params.size())
throw Exception(aggregate_function_name_with_params + " doesn't look like aggregate function name in " + error_context + ".",
ErrorCodes::BAD_ARGUMENTS);
aggregate_function_name = aggregate_function_name_with_params.substr(0, pos);
std::string parameters_str = aggregate_function_name_with_params.substr(pos + 1, aggregate_function_name_with_params.size() - pos - 2);
if (aggregate_function_name.empty())
throw Exception(aggregate_function_name_with_params + " doesn't look like aggregate function name in " + error_context + ".",
ErrorCodes::BAD_ARGUMENTS);
ParserExpressionList params_parser(false);
ASTPtr args_ast = parseQuery(params_parser,
parameters_str.data(), parameters_str.data() + parameters_str.size(),
"parameters of aggregate function in " + error_context, 0, DBMS_DEFAULT_MAX_PARSER_DEPTH);
if (args_ast->children.empty())
throw Exception("Incorrect list of parameters to aggregate function "
+ aggregate_function_name, ErrorCodes::BAD_ARGUMENTS);
aggregate_function_parameters = getAggregateFunctionParametersArray(args_ast, error_context, context);
}
}