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-- No derived tables
SELECT * FROM x;
SELECT * FROM x;
-- Unaliased derived tables
SELECT a FROM (SELECT b FROM (SELECT c FROM x));
WITH cte AS (SELECT c FROM x), cte_2 AS (SELECT b FROM cte AS cte) SELECT a FROM cte_2 AS cte_2;
-- Joined derived table inside nested derived table
SELECT b FROM (SELECT b FROM (SELECT b FROM x JOIN (SELECT b FROM y) AS y ON x.b = y.b));
WITH y_2 AS (SELECT b FROM y), cte AS (SELECT b FROM x JOIN y_2 AS y ON x.b = y.b), cte_2 AS (SELECT b FROM cte AS cte) SELECT b FROM cte_2 AS cte_2;
-- Aliased derived tables
SELECT a FROM (SELECT b FROM (SELECT c FROM x) AS y) AS z;
WITH y AS (SELECT c FROM x), z AS (SELECT b FROM y AS y) SELECT a FROM z AS z;
-- Existing CTEs
WITH q AS (SELECT c FROM x) SELECT a FROM (SELECT b FROM q AS y) AS z;
WITH q AS (SELECT c FROM x), z AS (SELECT b FROM q AS y) SELECT a FROM z AS z;
-- Derived table inside CTE
WITH x AS (SELECT a FROM (SELECT a FROM x) AS y) SELECT a FROM x;
WITH y AS (SELECT a FROM x), x AS (SELECT a FROM y AS y) SELECT a FROM x;
-- Name conflicts with existing outer derived table
SELECT a FROM (SELECT b FROM (SELECT c FROM x) AS y) AS y;
WITH y AS (SELECT c FROM x), y_2 AS (SELECT b FROM y AS y) SELECT a FROM y_2 AS y;
-- Name conflicts with outer join
SELECT a, b FROM (SELECT c FROM (SELECT d FROM x) AS x) AS y JOIN x ON x.a = y.a;
WITH x_2 AS (SELECT d FROM x), y AS (SELECT c FROM x_2 AS x) SELECT a, b FROM y AS y JOIN x ON x.a = y.a;
-- Name conflicts with table name that is selected in another branch
SELECT * FROM (SELECT * FROM (SELECT a FROM x) AS x) AS y JOIN (SELECT * FROM x) AS z ON x.a = y.a;
WITH x_2 AS (SELECT a FROM x), y AS (SELECT * FROM x_2 AS x), z AS (SELECT * FROM x) SELECT * FROM y AS y JOIN z AS z ON x.a = y.a;
-- Name conflicts with table alias
SELECT a FROM (SELECT a FROM (SELECT a FROM x) AS y) AS z JOIN q AS y;
WITH y AS (SELECT a FROM x), z AS (SELECT a FROM y AS y) SELECT a FROM z AS z JOIN q AS y;
-- Name conflicts with existing CTE
WITH y AS (SELECT a FROM (SELECT a FROM x) AS y) SELECT a FROM y;
WITH y_2 AS (SELECT a FROM x), y AS (SELECT a FROM y_2 AS y) SELECT a FROM y;
-- Union
SELECT 1 AS x, 2 AS y UNION ALL SELECT 1 AS x, 2 AS y;
WITH cte AS (SELECT 1 AS x, 2 AS y) SELECT cte.x AS x, cte.y AS y FROM cte AS cte UNION ALL SELECT cte.x AS x, cte.y AS y FROM cte AS cte;
-- Union of selects with derived tables
(SELECT a FROM (SELECT b FROM x)) UNION (SELECT a FROM (SELECT b FROM y));
WITH cte AS (SELECT b FROM x), cte_2 AS (SELECT a FROM cte AS cte), cte_3 AS (SELECT b FROM y), cte_4 AS (SELECT a FROM cte_3 AS cte_3) (SELECT cte_2.a AS a FROM cte_2 AS cte_2) UNION (SELECT cte_4.a AS a FROM cte_4 AS cte_4);
-- Subquery
SELECT a FROM x WHERE b = (SELECT y.c FROM y);
SELECT a FROM x WHERE b = (SELECT y.c FROM y);
-- Correlated subquery
SELECT a FROM x WHERE b = (SELECT c FROM y WHERE y.a = x.a);
SELECT a FROM x WHERE b = (SELECT c FROM y WHERE y.a = x.a);
-- Duplicate CTE
SELECT a FROM (SELECT b FROM x) AS y JOIN (SELECT b FROM x) AS z;
WITH y AS (SELECT b FROM x) SELECT a FROM y AS y JOIN y AS z;
-- Doubly duplicate CTE
SELECT * FROM (SELECT * FROM x JOIN (SELECT * FROM x) AS y) AS z JOIN (SELECT * FROM x JOIN (SELECT * FROM x) AS y) AS q;
WITH y AS (SELECT * FROM x), z AS (SELECT * FROM x JOIN y AS y) SELECT * FROM z AS z JOIN z AS q;
-- Another duplicate...
SELECT x.id FROM (SELECT * FROM x AS x JOIN y AS y ON x.id = y.id) AS x JOIN (SELECT * FROM x AS x JOIN y AS y ON x.id = y.id) AS y ON x.id = y.id;
WITH x_2 AS (SELECT * FROM x AS x JOIN y AS y ON x.id = y.id) SELECT x.id FROM x_2 AS x JOIN x_2 AS y ON x.id = y.id;
-- Root subquery
(SELECT * FROM (SELECT * FROM x)) LIMIT 1;
(WITH cte AS (SELECT * FROM x) SELECT * FROM cte AS cte) LIMIT 1;
-- Existing duplicate CTE
WITH y AS (SELECT a FROM x) SELECT a FROM (SELECT a FROM x) AS y JOIN y AS z;
WITH y AS (SELECT a FROM x) SELECT a FROM y AS y JOIN y AS z;
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