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70 lines
2.5 KiB
C++
70 lines
2.5 KiB
C++
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#include <TableFunctions/ITableFunction.h>
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#include <TableFunctions/ITableFunctionFileLike.h>
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#include <Parsers/ASTFunction.h>
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#include <Parsers/ASTLiteral.h>
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#include <Common/Exception.h>
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#include <Common/typeid_cast.h>
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#include <Storages/StorageFile.h>
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#include <DataTypes/DataTypeFactory.h>
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#include <Interpreters/Context.h>
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#include <Interpreters/evaluateConstantExpression.h>
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#include <boost/algorithm/string.hpp>
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#include <Common/Exception.h>
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#include <Common/typeid_cast.h>
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namespace DB
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{
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namespace ErrorCodes
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{
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extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
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}
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StoragePtr ITableFunctionFileLike::executeImpl(const ASTPtr & ast_function, const Context & context) const
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{
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// Parse args
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ASTs & args_func = typeid_cast<ASTFunction &>(*ast_function).children;
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if (args_func.size() != 1)
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throw Exception("Table function '" + getName() + "' must have arguments.", ErrorCodes::LOGICAL_ERROR);
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ASTs & args = typeid_cast<ASTExpressionList &>(*args_func.at(0)).children;
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if (args.size() != 3)
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throw Exception("Table function '" + getName() + "' requires exactly 3 arguments: source, format and structure.",
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ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
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for (size_t i = 0; i < 3; ++i)
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args[i] = evaluateConstantExpressionOrIdentifierAsLiteral(args[i], context);
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std::string source = static_cast<const ASTLiteral &>(*args[0]).value.safeGet<String>();
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std::string format = static_cast<const ASTLiteral &>(*args[1]).value.safeGet<String>();
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std::string structure = static_cast<const ASTLiteral &>(*args[2]).value.safeGet<String>();
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// Create sample block
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std::vector<std::string> structure_vals;
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boost::split(structure_vals, structure, boost::algorithm::is_any_of(" ,"), boost::algorithm::token_compress_on);
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if (structure_vals.size() % 2 != 0)
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throw Exception("Odd number of elements in section structure: must be a list of name type pairs", ErrorCodes::LOGICAL_ERROR);
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Block sample_block;
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const DataTypeFactory & data_type_factory = DataTypeFactory::instance();
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for (size_t i = 0, size = structure_vals.size(); i < size; i += 2)
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{
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ColumnWithTypeAndName column;
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column.name = structure_vals[i];
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column.type = data_type_factory.get(structure_vals[i + 1]);
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column.column = column.type->createColumn();
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sample_block.insert(std::move(column));
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}
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// Create table
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StoragePtr storage = getStorage(source, format, sample_block, const_cast<Context &>(context));
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storage->startup();
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return storage;
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}
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}
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