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#include <TableFunctions/ITableFunction.h>
#include <TableFunctions/TableFunctionNumbers.h>
#include <TableFunctions/TableFunctionFactory.h>
#include <Parsers/ASTFunction.h>
#include <Common/typeid_cast.h>
#include <Common/FieldVisitorToString.h>
#include <Storages/System/StorageSystemNumbers.h>
#include <Interpreters/evaluateConstantExpression.h>
#include <Interpreters/convertFieldToType.h>
#include <Interpreters/Context.h>
#include <DataTypes/DataTypesNumber.h>
#include "registerTableFunctions.h"
namespace DB
{
namespace ErrorCodes
{
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
}
template <bool multithreaded>
ColumnsDescription TableFunctionNumbers<multithreaded>::getActualTableStructure(ContextPtr /*context*/, bool /*is_insert_query*/) const
{
/// NOTE: https://bugs.llvm.org/show_bug.cgi?id=47418
return ColumnsDescription{{{"number", std::make_shared<DataTypeUInt64>()}}};
}
template <bool multithreaded>
StoragePtr TableFunctionNumbers<multithreaded>::executeImpl(const ASTPtr & ast_function, ContextPtr context, const std::string & table_name, ColumnsDescription /*cached_columns*/, bool /*is_insert_query*/) const
{
if (const auto * function = ast_function->as<ASTFunction>())
{
auto arguments = function->arguments->children;
if (arguments.size() != 1 && arguments.size() != 2)
throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Table function '{}' requires 'length' or 'offset, length'.", getName());
UInt64 offset = arguments.size() == 2 ? evaluateArgument(context, arguments[0]) : 0;
UInt64 length = arguments.size() == 2 ? evaluateArgument(context, arguments[1]) : evaluateArgument(context, arguments[0]);
auto res = std::make_shared<StorageSystemNumbers>(StorageID(getDatabaseName(), table_name), multithreaded, length, offset, false);
res->startup();
return res;
}
throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Table function '{}' requires 'limit' or 'offset, limit'.", getName());
}
void registerTableFunctionNumbers(TableFunctionFactory & factory)
{
factory.registerFunction<TableFunctionNumbers<true>>({.documentation = {}, .allow_readonly = true});
factory.registerFunction<TableFunctionNumbers<false>>({.documentation = {}, .allow_readonly = true});
}
template <bool multithreaded>
UInt64 TableFunctionNumbers<multithreaded>::evaluateArgument(ContextPtr context, ASTPtr & argument) const
{
const auto & [field, type] = evaluateConstantExpression(argument, context);
if (!isNativeNumber(type))
throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Illegal type {} expression, must be numeric type", type->getName());
Field converted = convertFieldToType(field, DataTypeUInt64());
if (converted.isNull())
throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "The value {} is not representable as UInt64",
applyVisitor(FieldVisitorToString(), field));
return converted.safeGet<UInt64>();
}
}
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