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Fix WHERE clause subquery extraction in parse_table_names() #12

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Fix WHERE clause subquery extraction in parse_table_names() #12

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71 changes: 68 additions & 3 deletions src/parse_tables.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,9 @@
#include "duckdb/parser/tableref/joinref.hpp"
#include "duckdb/parser/tableref/subqueryref.hpp"
#include "duckdb/function/scalar/nested_functions.hpp"
#include "duckdb/parser/expression/subquery_expression.hpp"
#include "duckdb/parser/parsed_expression_iterator.hpp"
#include "duckdb/parser/result_modifier.hpp"

namespace duckdb {

Expand Down Expand Up @@ -73,6 +76,12 @@ static unique_ptr<GlobalTableFunctionState> ParseTablesInit(ClientContext &conte
return make_uniq<ParseTablesState>();
}

static void ExtractTablesFromExpression(
const duckdb::ParsedExpression &expr,
std::vector<TableRefResult> &results,
const duckdb::CommonTableExpressionMap *cte_map = nullptr
);

static void ExtractTablesFromRef(
const duckdb::TableRef &ref,
std::vector<TableRefResult> &results,
Expand All @@ -89,7 +98,7 @@ static void ExtractTablesFromRef(

if (cte_map && cte_map->map.find(base.table_name) != cte_map->map.end()) {
context_label = TableContext::FromCTE;
} else if (is_top_level) {
} else if (is_top_level && context != TableContext::Subquery) {
context_label = TableContext::From;
}

Expand All @@ -104,12 +113,15 @@ static void ExtractTablesFromRef(
auto &join = (JoinRef &)ref;
ExtractTablesFromRef(*join.left, results, TableContext::JoinLeft, is_top_level, cte_map);
ExtractTablesFromRef(*join.right, results, TableContext::JoinRight, false, cte_map);
if (join.condition) {
ExtractTablesFromExpression(*join.condition, results, cte_map);
}
break;
}
case TableReferenceType::SUBQUERY: {
auto &subquery = (SubqueryRef &)ref;
if (subquery.subquery && subquery.subquery->node) {
ExtractTablesFromQueryNode(*subquery.subquery->node, results, TableContext::Subquery, cte_map);
ExtractTablesFromQueryNode(*subquery.subquery->node, results, TableContext::From, cte_map);
}
break;
}
Expand All @@ -118,6 +130,24 @@ static void ExtractTablesFromRef(
}
}

static void ExtractTablesFromExpression(
const duckdb::ParsedExpression &expr,
std::vector<TableRefResult> &results,
const duckdb::CommonTableExpressionMap *cte_map
) {
using namespace duckdb;

if (expr.expression_class == ExpressionClass::SUBQUERY) {
auto &subquery_expr = (SubqueryExpression &)expr;
if (subquery_expr.subquery && subquery_expr.subquery->node) {
ExtractTablesFromQueryNode(*subquery_expr.subquery->node, results, TableContext::Subquery, cte_map);
}
}

ParsedExpressionIterator::EnumerateChildren(expr, [&](const ParsedExpression &child) {
ExtractTablesFromExpression(child, results, cte_map);
});
}

static void ExtractTablesFromQueryNode(
const duckdb::QueryNode &node,
Expand All @@ -144,7 +174,42 @@ static void ExtractTablesFromQueryNode(
if (select_node.from_table) {
ExtractTablesFromRef(*select_node.from_table, results, context, true, &select_node.cte_map);
}
}

for (const auto &expr : select_node.select_list) {
if (expr) {
ExtractTablesFromExpression(*expr, results, &select_node.cte_map);
}
}

if (select_node.where_clause) {
ExtractTablesFromExpression(*select_node.where_clause, results, &select_node.cte_map);
}

for (const auto &expr : select_node.groups.group_expressions) {
if (expr) {
ExtractTablesFromExpression(*expr, results, &select_node.cte_map);
}
}

if (select_node.having) {
ExtractTablesFromExpression(*select_node.having, results, &select_node.cte_map);
}

if (select_node.qualify) {
ExtractTablesFromExpression(*select_node.qualify, results, &select_node.cte_map);
}

for (const auto &modifier : select_node.modifiers) {
if (modifier->type == ResultModifierType::ORDER_MODIFIER) {
auto &order_modifier = (OrderModifier &)*modifier;
for (const auto &order : order_modifier.orders) {
if (order.expression) {
ExtractTablesFromExpression(*order.expression, results, &select_node.cte_map);
}
}
}
}
}
// additional step necessary for duckdb v1.4.0: unwrap CTE node
else if (node.type == QueryNodeType::CTE_NODE) {
auto &cte_node = (CTENode &)node;
Expand Down
20 changes: 19 additions & 1 deletion test/sql/parse_tools/scalar_functions/parse_tables.test
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Original file line number Diff line number Diff line change
Expand Up @@ -73,4 +73,22 @@ select parse_tables('SELECT 1;');
query I
SELECT parse_tables('SELECT * FROM WHERE');
----
[]
[]

# WHERE clause subquery
query I
SELECT parse_tables('SELECT * FROM users WHERE id IN (SELECT user_id FROM orders)');
----
[{'schema': main, 'table': users, 'context': from}, {'schema': main, 'table': orders, 'context': subquery}]

# nested subqueries
query I
SELECT parse_tables('SELECT * FROM a WHERE x IN (SELECT y FROM b WHERE z IN (SELECT w FROM c))');
----
[{'schema': main, 'table': a, 'context': from}, {'schema': main, 'table': b, 'context': subquery}, {'schema': main, 'table': c, 'context': subquery}]

# multiple contexts with subqueries
query I
SELECT parse_tables('SELECT (SELECT max(x) FROM b) FROM a WHERE y IN (SELECT z FROM c)');
----
[{'schema': main, 'table': a, 'context': from}, {'schema': main, 'table': b, 'context': subquery}, {'schema': main, 'table': c, 'context': subquery}]
53 changes: 52 additions & 1 deletion test/sql/parse_tools/table_functions/parse_tables.test
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Original file line number Diff line number Diff line change
Expand Up @@ -113,4 +113,55 @@ SELECT * FROM parse_tables('SELECT 1;');
# malformed SQL should not error
query III
SELECT * FROM parse_tables('SELECT * FROM WHERE');
----
----

# WHERE clause subquery
query III
SELECT * FROM parse_tables('SELECT * FROM users WHERE id IN (SELECT user_id FROM orders)');
----
main users from
main orders subquery

# WHERE clause with schema-qualified subquery
query III
SELECT * FROM parse_tables('SELECT * FROM schema1.users WHERE id IN (SELECT user_id FROM schema2.orders)');
----
schema1 users from
schema2 orders subquery

# nested subqueries in WHERE
query III
SELECT * FROM parse_tables('SELECT * FROM a WHERE x IN (SELECT y FROM b WHERE z IN (SELECT w FROM c))');
----
main a from
main b subquery
main c subquery

# SELECT list subquery (scalar subquery)
query III
SELECT * FROM parse_tables('SELECT id, (SELECT max(price) FROM products) AS max_price FROM orders');
----
main orders from
main products subquery

# HAVING clause subquery
query III
SELECT * FROM parse_tables('SELECT dept FROM employees GROUP BY dept HAVING count(*) > (SELECT avg(cnt) FROM dept_sizes)');
----
main employees from
main dept_sizes subquery

# JOIN condition subquery
query III
SELECT * FROM parse_tables('SELECT * FROM a JOIN b ON a.id = b.id AND b.status IN (SELECT code FROM statuses)');
----
main a from
main b join_right
main statuses subquery

# ORDER BY clause subquery
query III
SELECT * FROM parse_tables('SELECT * FROM users ORDER BY (SELECT max(score) FROM rankings WHERE user_id = users.id)');
----
main users from
main rankings subquery