ClickHouse/dbms/src/Interpreters/InterpreterInsertQuery.cpp

#include <IO/ConcatReadBuffer.h>

#include <Common/typeid_cast.h>

#include <DataStreams/AddingDefaultBlockOutputStream.h>
#include <DataStreams/CastTypeBlockInputStream.h>
#include <DataStreams/CountingBlockOutputStream.h>
#include <DataStreams/MaterializingBlockOutputStream.h>
#include <DataStreams/NullAndDoCopyBlockInputStream.h>
#include <DataStreams/NullableAdapterBlockInputStream.h>
#include <DataStreams/ProhibitColumnsBlockOutputStream.h>
#include <DataStreams/PushingToViewsBlockOutputStream.h>
#include <DataStreams/SquashingBlockOutputStream.h>
#include <DataStreams/copyData.h>

#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTInsertQuery.h>
#include <Parsers/ASTSelectQuery.h>

#include <Interpreters/InterpreterInsertQuery.h>
#include <Interpreters/InterpreterSelectQuery.h>

#include <TableFunctions/TableFunctionFactory.h>
#include <Parsers/ASTFunction.h>

namespace ProfileEvents
{
extern const Event InsertQuery;
}

namespace DB
{
namespace ErrorCodes
{
    extern const int NO_SUCH_COLUMN_IN_TABLE;
    extern const int READONLY;
}


InterpreterInsertQuery::InterpreterInsertQuery(
    const ASTPtr & query_ptr_, const Context & context_, bool allow_materialized_)
    : query_ptr(query_ptr_), context(context_), allow_materialized(allow_materialized_)
{
    ProfileEvents::increment(ProfileEvents::InsertQuery);
}


StoragePtr InterpreterInsertQuery::loadTable()
{
    ASTInsertQuery & query = typeid_cast<ASTInsertQuery &>(*query_ptr);

    if (query.table_function)
    {
        auto table_function = typeid_cast<const ASTFunction *>(query.table_function.get());
        const auto & factory = TableFunctionFactory::instance();
        return factory.get(table_function->name, context)->execute(query.table_function, context);
    }

    /// In what table to write.
    return context.getTable(query.database, query.table);
}

StoragePtr InterpreterInsertQuery::getTable()
{
    if (!cached_table)
        cached_table = loadTable();

    return cached_table;
}

Block InterpreterInsertQuery::getSampleBlock()
{
    ASTInsertQuery & query = typeid_cast<ASTInsertQuery &>(*query_ptr);

    /// If the query does not include information about columns
    if (!query.columns)
        return getTable()->getSampleBlockNonMaterialized();

    Block table_sample = getTable()->getSampleBlock();

    /// Form the block based on the column names from the query
    Block res;
    for (const auto & identifier : query.columns->children)
    {
        std::string current_name = identifier->getColumnName();

        /// The table does not have a column with that name
        if (!table_sample.has(current_name))
            throw Exception("No such column " + current_name + " in table " + query.table, ErrorCodes::NO_SUCH_COLUMN_IN_TABLE);

        ColumnWithTypeAndName col;
        col.name = current_name;
        col.type = table_sample.getByName(current_name).type;
        col.column = col.type->createColumn();
        res.insert(std::move(col));
    }

    return res;
}


BlockIO InterpreterInsertQuery::execute()
{
    ASTInsertQuery & query = typeid_cast<ASTInsertQuery &>(*query_ptr);
    checkAccess(query);
    StoragePtr table = getTable();

    auto table_lock = table->lockStructure(true, __PRETTY_FUNCTION__);

    NamesAndTypesList required_columns = table->getColumnsList();

    /// We create a pipeline of several streams, into which we will write data.
    BlockOutputStreamPtr out;

    out = std::make_shared<PushingToViewsBlockOutputStream>(query.database, query.table, table, context, query_ptr, query.no_destination);

    out = std::make_shared<MaterializingBlockOutputStream>(out);

    out = std::make_shared<AddingDefaultBlockOutputStream>(
        out, required_columns, table->column_defaults, context, static_cast<bool>(context.getSettingsRef().strict_insert_defaults));

    if (!allow_materialized)
        out = std::make_shared<ProhibitColumnsBlockOutputStream>(out, table->materialized_columns);

    out = std::make_shared<SquashingBlockOutputStream>(
        out, context.getSettingsRef().min_insert_block_size_rows, context.getSettingsRef().min_insert_block_size_bytes);

    auto out_wrapper = std::make_shared<CountingBlockOutputStream>(out);
    out_wrapper->setProcessListElement(context.getProcessListElement());
    out = std::move(out_wrapper);

    BlockIO res;
    res.out_sample = getSampleBlock();

    /// What type of query: INSERT or INSERT SELECT?
    if (!query.select)
    {
        res.out = out;
    }
    else
    {
        InterpreterSelectQuery interpreter_select{query.select, context};
        res.in_sample = interpreter_select.getSampleBlock();

        res.in = interpreter_select.execute().in;

        res.in = std::make_shared<NullableAdapterBlockInputStream>(res.in, res.in_sample, res.out_sample);
        res.in = std::make_shared<CastTypeBlockInputStream>(context, res.in, res.out_sample);
        res.in = std::make_shared<NullAndDoCopyBlockInputStream>(res.in, out);
    }

    return res;
}

void InterpreterInsertQuery::checkAccess(const ASTInsertQuery & query)
{
    const Settings & settings = context.getSettingsRef();
    auto readonly = settings.limits.readonly;

    if (!readonly || (query.database.empty() && context.tryGetExternalTable(query.table) && readonly >= 2))
    {
        return;
    }

    throw Exception("Cannot insert into table in readonly mode", ErrorCodes::READONLY);
}
}