Advanced Query Usage
The query result from semantic_view() is a standard relational result set and can be used like a regular table in subqueries, CTEs, JOINs, and CTAS.
The following examples are based on doc_test.emp_dept_analysis (defined in Create Semantic View).
Subqueries
Semantic views can serve as the data source for subqueries, with the outer query able to further filter or process the results:
SELECT dept, avg_sal
FROM (
SELECT * FROM semantic_view(
doc_test.emp_dept_analysis,
DIMENSIONS emps.department,
METRICS emps.avg_salary
)
) t
WHERE avg_salary > 9000;
+-------------+--------------+
| dept | avg_sal |
+-------------+--------------+
| Engineering | 11500.000000 |
+-------------+--------------+
CTE (WITH Clause)
Semantic views can be placed in CTEs for easy reuse within the same query:
WITH dept_stats AS (
SELECT * FROM semantic_view(
doc_test.emp_dept_analysis,
DIMENSIONS emps.department,
METRICS emps.avg_salary,
METRICS emps.total_employees
)
)
SELECT *
FROM dept_stats
WHERE total_employees > 1
ORDER BY avg_salary DESC;
+-------------+--------------+-----------------+
| department | avg_salary | total_employees |
+-------------+--------------+-----------------+
| Engineering | 11500.000000 | 2 |
| Marketing | 8750.000000 | 2 |
+-------------+--------------+-----------------+
JOIN with Regular Tables
Semantic view results can be further joined with regular tables:
SELECT
sv.department,
sv.avg_salary,
d.manager
FROM semantic_view(
doc_test.emp_dept_analysis,
DIMENSIONS emps.department,
METRICS emps.avg_salary
) sv
JOIN doc_test.departments d ON sv.department = d.dept_name;
+-------------+--------------+---------+
| department | avg_salary | manager |
+-------------+--------------+---------+
| Engineering | 11500.000000 | Frank |
| Marketing | 8750.000000 | Grace |
| HR | 7500.000000 | Henry |
+-------------+--------------+---------+
CTAS (CREATE TABLE AS SELECT)
Semantic view query results can be materialized into regular tables for further processing or export:
CREATE TABLE doc_test.dept_salary_snapshot AS
SELECT * FROM semantic_view(
doc_test.emp_dept_analysis,
DIMENSIONS emps.department,
METRICS emps.total_employees,
METRICS emps.avg_salary,
METRICS emps.max_salary
);
INSERT INTO ... SELECT
Similarly, you can write semantic view query results into an existing table:
INSERT INTO doc_test.dept_salary_snapshot
SELECT * FROM semantic_view(
doc_test.emp_dept_analysis,
DIMENSIONS emps.department,
METRICS emps.total_employees,
METRICS emps.avg_salary,
METRICS emps.max_salary
);
Notes
- Column names in subqueries come from the result columns of
semantic_view() (i.e., dimension names and metric names), not from the original physical table column names.
CTAS and INSERT INTO create materialized snapshots that do not automatically refresh when the underlying data of the semantic view changes. For automatic refresh, define it as a Dynamic Table: CREATE DYNAMIC TABLE ... AS SELECT * FROM semantic_view(...).
