uint32_t len = static_cast<uint32_t>(std::strlen(s));

char* buf = static_cast<char*>(arena.allocate(len));

std::memcpy(buf, s, len);

return StringRef{buf, len};

uint16_t n = static_cast<uint16_t>(vals.size());

Row r = make_row(arena, n);

uint16_t i = 0;

for (auto& v : vals) r.set(i++, v);

return r;

Arena data_arena{65536, 1048576};

InMemoryCatalog catalog;

FunctionRegistry<Dialect::MySQL> functions;

Parser<Dialect::MySQL> parser;

InMemoryDataSource* users_source = nullptr;

void SetUp() override {

functions.register_builtins();

catalog.add_table("", "users", {

{"id", SqlType::make_int(), false},

{"name", SqlType::make_varchar(255), true},

{"age", SqlType::make_int(), true},

{"dept", SqlType::make_varchar(50), true},

});

std::vector<Row> rows = {

build_row(data_arena, {value_int(1), value_string(arena_str(data_arena, "Alice")), value_int(25), value_string(arena_str(data_arena, "Engineering"))}),

build_row(data_arena, {value_int(2), value_string(arena_str(data_arena, "Bob")), value_int(30), value_string(arena_str(data_arena, "Sales"))}),

build_row(data_arena, {value_int(3), value_string(arena_str(data_arena, "Carol")), value_int(17), value_string(arena_str(data_arena, "Engineering"))}),

build_row(data_arena, {value_int(4), value_string(arena_str(data_arena, "Dave")), value_int(22), value_string(arena_str(data_arena, "Sales"))}),

build_row(data_arena, {value_int(5), value_string(arena_str(data_arena, "Eve")), value_int(35), value_string(arena_str(data_arena, "Engineering"))}),

};

users_source = new InMemoryDataSource(

catalog.get_table(StringRef{"users", 5}), std::move(rows));

}

void TearDown() override {

delete users_source;

}

ResultSet run_query(const char* sql) {

parser.reset();

auto r = parser.parse(sql, std::strlen(sql));

if (r.status != ParseResult::OK || !r.ast) return {};

PlanExecutor<Dialect::MySQL> executor(functions, catalog, parser.arena());

executor.add_data_source("users", users_source);

return executor.execute_with_cte(r.ast);

}

auto rs = run_query("WITH active AS (SELECT * FROM users WHERE age > 18) SELECT * FROM active");

// Alice(25), Bob(30), Dave(22), Eve(35) = 4 rows

ASSERT_EQ(rs.row_count(), 4u);

auto rs = run_query(

"WITH dept_counts AS ("

" SELECT dept, COUNT(*) AS cnt FROM users GROUP BY dept"

") SELECT * FROM dept_counts WHERE cnt > 2");

// Engineering has 3 users, Sales has 2

// Only Engineering has cnt > 2

ASSERT_EQ(rs.row_count(), 1u);

// The dept should be Engineering

EXPECT_EQ(rs.rows[0].get(0).tag, Value::TAG_STRING);

auto rs = run_query(

"WITH eng AS (SELECT * FROM users WHERE dept = 'Engineering'), "

" sales AS (SELECT * FROM users WHERE dept = 'Sales') "

"SELECT * FROM eng");

// Engineering: Alice, Carol, Eve = 3 rows

ASSERT_EQ(rs.row_count(), 3u);

auto rs = run_query(

"WITH adults AS (SELECT name, age FROM users WHERE age >= 25) "

"SELECT * FROM adults WHERE age >= 30");

// Bob(30), Eve(35) = 2 rows

ASSERT_EQ(rs.row_count(), 2u);