# name: test/sql/pivot/test_unpivot.test
# description: Test standard SQL unpivot syntax
# group: [pivot]

# example taken from the snowflake docs
# https://docs.snowflake.com/en/sql-reference/constructs/unpivot

statement ok
PRAGMA enable_verification

statement ok
CREATE OR REPLACE TABLE monthly_sales(empid INT, dept TEXT, Jan INT, Feb INT, Mar INT, April INT);

statement ok
INSERT INTO monthly_sales VALUES
    (1, 'electronics', 100, 200, 300, 100),
    (2, 'clothes', 100, 300, 150, 200),
    (3, 'cars', 200, 400, 100, 50);

# standard UNPIVOT
query IIII
SELECT * FROM monthly_sales
    UNPIVOT(sales FOR month IN (jan, feb, mar, april))
    ORDER BY empid;
----
1	electronics	Jan	100
1	electronics	Feb	200
1	electronics	Mar	300
1	electronics	April	100
2	clothes	Jan	100
2	clothes	Feb	300
2	clothes	Mar	150
2	clothes	April	200
3	cars	Jan	200
3	cars	Feb	400
3	cars	Mar	100
3	cars	April	50

# leaving out an entry works - it just does not unpivot that entry and leave it as a normal column
query IIIII
SELECT empid, dept, april, month, sales FROM monthly_sales
    UNPIVOT(sales FOR month IN (jan, feb, mar))
    ORDER BY empid;
----
1	electronics	100	Jan	100
1	electronics	100	Feb	200
1	electronics	100	Mar	300
2	clothes	200	Jan	100
2	clothes	200	Feb	300
2	clothes	200	Mar	150
3	cars	50	Jan	200
3	cars	50	Feb	400
3	cars	50	Mar	100

# alias in pivots
query IIII
SELECT * FROM monthly_sales
    UNPIVOT(sales FOR month IN (jan AS January, feb AS February, mar AS March, april))
    ORDER BY empid;
----
1	electronics	January	100
1	electronics	February	200
1	electronics	March	300
1	electronics	April	100
2	clothes	January	100
2	clothes	February	300
2	clothes	March	150
2	clothes	April	200
3	cars	January	200
3	cars	February	400
3	cars	March	100
3	cars	April	50

# alias the unpivot clause
query IIII
SELECT p.id, p.type, p.m, p.vals FROM monthly_sales
    UNPIVOT(sales FOR month IN (jan, feb, mar, april)) AS p(id, type, m, vals);
----
1	electronics	Jan	100
1	electronics	Feb	200
1	electronics	Mar	300
1	electronics	April	100
2	clothes	Jan	100
2	clothes	Feb	300
2	clothes	Mar	150
2	clothes	April	200
3	cars	Jan	200
3	cars	Feb	400
3	cars	Mar	100
3	cars	April	50

# multi-column unpivot
query IIIII
SELECT empid, dept, month, sales_jan_feb, sales_mar_apr FROM monthly_sales
    UNPIVOT((sales_jan_feb, sales_mar_apr) FOR month IN ((jan, feb), (mar, april)));
----
1	electronics	Jan_Feb	100	200
1	electronics	Mar_April	300	100
2	clothes	Jan_Feb	100	300
2	clothes	Mar_April	150	200
3	cars	Jan_Feb	200	400
3	cars	Mar_April	100	50

# multiple names in FOR clause
statement error
SELECT * FROM monthly_sales
    UNPIVOT((sales_jan_feb, sales_mar_apr) FOR (month, month2) IN ((jan, feb), (mar, april)));
----
UNPIVOT requires a single column name

# count mismatch
statement error
SELECT * FROM monthly_sales
    UNPIVOT(sales_jan_feb FOR month IN ((jan, feb), (mar, april)));
----
UNPIVOT name count mismatch

statement error
SELECT * FROM monthly_sales
    UNPIVOT((a, b, c) FOR month IN ((jan, feb), (mar, april)));
----
UNPIVOT name count mismatch

statement error
SELECT empid, dept, month, sales_jan_feb, sales_mar_apr FROM monthly_sales
    UNPIVOT((sales_jan_feb, sales_mar_apr) FOR month IN ((jan, feb), mar));
----
UNPIVOT value count mismatch

# unrecognized entry in unpivot
statement error
SELECT empid, dept, april, month, sales FROM monthly_sales
    UNPIVOT(sales FOR month IN (jan, feb, mar, dec))
    ORDER BY empid;
----
referenced in UNPIVOT but no matching entry was found in the table

# mix of types in pivot
statement error
SELECT * FROM monthly_sales
    UNPIVOT(sales FOR month IN (empid, dept, jan, feb, mar, april))
----
an explicit cast is required

# unpivot over subquery
query IIIII
UNPIVOT (SELECT * FROM monthly_sales)
    ON jan, feb, mar april
    INTO
        NAME month
        VALUE sales;
----
1	electronics	100	Jan	100
1	electronics	100	Feb	200
1	electronics	100	april	300
2	clothes	200	Jan	100
2	clothes	200	Feb	300
2	clothes	200	april	150
3	cars	50	Jan	200
3	cars	50	Feb	400
3	cars	50	april	100

# empty IN clause
statement error
SELECT * FROM monthly_sales
    UNPIVOT(sales FOR month IN ())
    ORDER BY empid;
----
syntax error

statement error
SELECT * FROM monthly_sales
    UNPIVOT(sales FOR month IN (''))
    ORDER BY empid;
----
empty column name

statement error
SELECT * FROM monthly_sales
    UNPIVOT(SUM(sales) FOR month IN (empid, dept, jan, feb, mar, april))
----
syntax error