ClickHouse/src/Parsers/InsertQuerySettingsPushDownVisitor.h
2022-11-17 18:16:32 +01:00

38 lines
965 B
C++

#pragma once
#include <Parsers/IAST.h>
#include <Interpreters/InDepthNodeVisitor.h>
namespace DB
{
class ASTSelectQuery;
struct SettingChange;
class SettingsChanges;
/// Pushdown SETTINGS clause to the INSERT from the SELECT query:
/// (since SETTINGS after SELECT will be parsed by the SELECT parser.)
///
/// NOTE: INSERT ... SELECT ... FORMAT Null SETTINGS max_insert_threads=10 works even without push down,
/// since ParserInsertQuery does not use ParserQueryWithOutput.
class InsertQuerySettingsPushDownMatcher
{
public:
using Visitor = InDepthNodeVisitor<InsertQuerySettingsPushDownMatcher, true>;
struct Data
{
ASTPtr & insert_settings_ast;
};
static bool needChildVisit(ASTPtr & node, const ASTPtr & child);
static void visit(ASTPtr & ast, Data & data);
private:
static void visit(ASTSelectQuery &, ASTPtr &, Data &);
};
using InsertQuerySettingsPushDownVisitor = InsertQuerySettingsPushDownMatcher::Visitor;
}