Counting and grouping challenge in a pivot table with T-SQL - sql

Question

I have a pivot table that converts a vertical database design to a horizontal one:
The source table:
Id ParentId Property Value
---------------------------------
1 1 Date 01-09-2015
2 1 CountValue 2
3 1 TypeA Value1
4 1 TypeB Value2
5 1 TypeC Value2
6 2 Date 15-10-2015
7 2 CountValue 3
8 2 TypeA Value3
9 2 TypeB Value22
10 2 TypeC Value99
After pivoting this looks like:
ParentId Date CountValue TypeA TypeB TypeC
----------------------------------------------------------
1 01-09-2015 2 Value1 Value2 Value2
2 15-10-2015 3 Value3 Value22 Value99
Then, there's a look-up table for valid values in columns TypeA, TypeB and TypeC:
Id Name Value
-----------------
1 TypeA Value1
2 TypeA Value2
3 TypeA Value3
4 TypeB Value20
5 TypeB Value21
6 TypeB Value22
7 TypeC Value1
8 TypeC Value2
So, given the above structure I'm looking for a way to query the pivot table in a way that I'll get a count of all invalid values in TypeA, TypeB and TypeC where Date is a valid date and CountValue is not empty and greater than 0.
How can I achieve a result that is expected and outputted like below:
Count Column
--------------
0 TypeA
1 TypeB
1 TypeC
I've accomplished the result by creating three several queries and glue the results using UNION, but I think it should also be possible using the pivot table, but I'm unsure how. Can the desired result be realized using the pivot table?
Note: the database used is a SQL Server 2005 database.

Answer 1

I would not approach this a PIVOT, otherwise you have to pivot your data, then unpivot it to get the output required. Breaking it down step by step you can get your valid parent IDs using this:
SELECT t.ParentID
FROM #T AS t
GROUP BY t.ParentID
HAVING ISDATE(MAX(CASE WHEN t.Property = 'Date' THEN t.Value END)) = 1
AND MAX(CASE WHEN t.Property = 'CountValue' THEN CONVERT(INT, t.Value) END) > 0;
The two having clauses limit this to your criteria of having a valid date, and a CountValue that is greater than 0
The next step would be to find your invalid properties:
SELECT t.*
FROM #T AS t
WHERE NOT EXISTS
( SELECT 1
FROM #V AS v
WHERE v.Name = t.Property
AND v.Value = t.Value
);
This will include Date, and CountValue, and also won't include TypeA because all the properties are valid, so a bit more work is required, we must find the distinct properties we are interested in:
SELECT DISTINCT Name
FROM #V
Now we can combine this with the invalid properties to get the count, and with the valid parent IDs to get the desired result:
WITH ValidParents AS
( SELECT t.ParentID
FROM #T AS t
GROUP BY t.ParentID
HAVING ISDATE(MAX(CASE WHEN t.Property = 'Date' THEN t.Value END)) = 1
AND MAX(CASE WHEN t.Property = 'CountValue' THEN CONVERT(INT, t.Value) END) > 0
), InvalidProperties AS
( SELECT t.Property
FROM #T AS t
WHERE t.ParentID IN (SELECT vp.ParentID FROM ValidParents AS vp)
AND NOT EXISTS
( SELECT 1
FROM #V AS v
WHERE v.Name = t.Property
AND v.Value = t.Value
)
)
SELECT [Count] = COUNT(t.Property),
[Column] = v.Name
FROM (SELECT DISTINCT Name FROM #V) AS V
LEFT JOIN InvalidProperties AS t
ON t.Property = v.Name
GROUP BY v.Name;
Which gives:
Count Column
--------------
0 TypeA
1 TypeB
1 TypeC
SCHEMA FOR ABOVE QUERIES
For SQL Server 2008+. Apologies, I don't have SQL Server 2005 anymore, and forgot it doesn't support table value constructors.
CREATE TABLE #T (Id INT, ParentId INT, Property VARCHAR(10), Value VARCHAR(10));
INSERT #T (Id, ParentId, Property, Value)
VALUES
(1, 1, 'Date', '01-09-2015'), (2, 1, 'CountValue', '2'), (3, 1, 'TypeA', 'Value1'),
(4, 1, 'TypeB', 'Value2'), (5, 1, 'TypeC', 'Value2'), (6, 2, 'Date', '15-10-2015'),
(7, 2, 'CountValue', '3'), (8, 2, 'TypeA', 'Value3'), (9, 2, 'TypeB', 'Value22'),
(10, 2, 'TypeC', 'Value99');
CREATE TABLE #V (ID INT, Name VARCHAR(5), Value VARCHAR(7));
INSERT #V (Id, Name, Value)
VALUES
(1, 'TypeA', 'Value1'), (2, 'TypeA', 'Value2'), (3, 'TypeA', 'Value3'),
(4, 'TypeB', 'Value20'), (5, 'TypeB', 'Value21'), (6, 'TypeB', 'Value22'),
(7, 'TypeC', 'Value1'), (8, 'TypeC', 'Value2');

Answer 2

Final result without PIVOT:
SELECT [count] = SUM(CASE WHEN l.id IS NULL THEN 1 ELSE 0 END)
,t.Property
FROM #lookup l
RIGHT JOIN #tab t
ON t.Property = l.Name
AND t.Value = l.Value
WHERE t.Property LIKE 'Type%'
GROUP BY t.Property;
LiveDemo
Data:
CREATE TABLE #tab(
Id INTEGER NOT NULL PRIMARY KEY
,ParentId INTEGER NOT NULL
,Property VARCHAR(10) NOT NULL
,Value VARCHAR(10) NOT NULL
);
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (1,1,'Date','01-09-2015');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (2,1,'CountValue','2');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (3,1,'TypeA','Value1');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (4,1,'TypeB','Value2');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (5,1,'TypeC','Value2');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (6,2,'Date','15-10-2015');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (7,2,'CountValue','3');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (8,2,'TypeA','Value3');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (9,2,'TypeB','Value22');
INSERT INTO #tab(Id,ParentId,Property,Value) VALUES (10,2,'TypeC','Value99');
CREATE TABLE #lookup(
Id INTEGER NOT NULL PRIMARY KEY
,Name VARCHAR(5) NOT NULL
,Value VARCHAR(7) NOT NULL
);
INSERT INTO #lookup(Id,Name,Value) VALUES (1,'TypeA','Value1');
INSERT INTO #lookup(Id,Name,Value) VALUES (2,'TypeA','Value2');
INSERT INTO #lookup(Id,Name,Value) VALUES (3,'TypeA','Value3');
INSERT INTO #lookup(Id,Name,Value) VALUES (4,'TypeB','Value20');
INSERT INTO #lookup(Id,Name,Value) VALUES (5,'TypeB','Value21');
INSERT INTO #lookup(Id,Name,Value) VALUES (6,'TypeB','Value22');
INSERT INTO #lookup(Id,Name,Value) VALUES (7,'TypeC','Value1');
INSERT INTO #lookup(Id,Name,Value) VALUES (8,'TypeC','Value2');
EDIT:
Adding more criteria:
LiveDemo2
SELECT [count] = SUM(CASE WHEN l.id IS NULL THEN 1 ELSE 0 END)
,t.Property
FROM #lookup l
RIGHT JOIN #tab t
ON t.Property = l.Name
AND t.Value = l.Value
WHERE t.Property LIKE 'Type%'
AND t.ParentId IN (SELECT ParentId FROM #tab WHERE Property = 'Date' AND ISDATE(VALUE) = 1)
AND t.ParentID IN (SELECT ParentId FROM #tab WHERE Property = 'CountValue' AND Value > 0)
GROUP BY t.Property;