solve: questions faizanxmulla#13, #14

Author: faizanxmulla

ankit-bansal-sql/medium-complex-sql-questions-playlist/13-infosys-sql-puzzle.md

@@ -0,0 +1,59 @@
+### Problem Statement
+
+Write a query to get `new value` from the value and the formula provided for each of the table. 
+
+**Explanation**: For the first row, the formula is `1+4`, which indicates that we need to sum the values from the 1st and 4th rows. This results in `10 + 20`, giving a new value of `30`.
+
+### Schema Setup
+
+```sql
+CREATE TABLE input (
+  id INT,
+  formula VARCHAR(10),
+  value INT
+);
+
+INSERT INTO input VALUES 
+(1, '1+4', 10),
+(2, '2+1', 5),
+(3, '3-2', 40),
+(4, '4-1', 20);
+```
+
+
+### Expected Output
+
+id | formula | value | new_value |
+--|--|--|--|
+1 | 1+4 | 10 | 30 |
+2 | 2+1 | 5 | 15 | 
+3 | 3-2 | 40 | 35 |
+4 | 4-1 | 20 | 10 |
+
+
+
+### Solution Query
+
+```sql
+WITH CTE as (
+    SELECT *,
+           SUBSTRING(formula, 1, 1)::int as first_digit,
+           SUBSTRING(formula, 3, 1)::int as second_digit,
+           SUBSTRING(formula, 2, 1) as operator
+    FROM   input
+)
+SELECT   c.id, 
+         c.formula, 
+         c.value,
+         CASE WHEN operator='+' THEN i1.value+i2.value ELSE i1.value-i2.value END as new_value
+FROM     CTE c JOIN input i1 ON c.first_digit=i1.id
+               JOIN input i2 ON c.second_digit=i2.id
+ORDER BY 1
+
+
+-- NOTE: 
+
+-- syntax --> SUBSTRING(string, start_position, length)
+
+-- also for the digits, instead of SUBSTRING, we could have just used LEFT and RIGHT.
+```

ankit-bansal-sql/medium-complex-sql-questions-playlist/14-ameriprise-team-members-criteria.md

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+### Problem Statement
+
+Write a query to return either `Y` or `N`.
+
+**Condition**: If both criteria 1 and criteria 2 are `Y` and at least 2 members have a value of `Y`, the output should be `Y`; otherwise, it should be `N`.
+
+### Schema Setup
+
+```sql
+CREATE TABLE data (
+    team_id VARCHAR(2),
+    member_id VARCHAR(10),
+    criteria_1 VARCHAR(1),
+    criteria_2 VARCHAR(1)
+);
+
+INSERT INTO data VALUES 
+('T1', 'T1_mbr1', 'Y', 'Y'),
+('T1', 'T1_mbr2', 'Y', 'Y'),
+('T1', 'T1_mbr3', 'Y', 'Y'),
+('T1', 'T1_mbr4', 'Y', 'Y'),
+('T1', 'T1_mbr5', 'Y', 'N'),
+('T2', 'T2_mbr1', 'Y', 'Y'),
+('T2', 'T2_mbr2', 'Y', 'N'),
+('T2', 'T2_mbr3', 'N', 'Y'),
+('T2', 'T2_mbr4', 'N', 'N'),
+('T2', 'T2_mbr5', 'N', 'N'),
+('T3', 'T3_mbr1', 'Y', 'Y'),
+('T3', 'T3_mbr2', 'Y', 'Y'),
+('T3', 'T3_mbr3', 'N', 'Y'),
+('T3', 'T3_mbr4', 'N', 'Y'),
+('T3', 'T3_mbr5', 'Y', 'N');
+```
+
+
+### Expected Output
+
+| team_id | member_id | criteria_1 | criteria_2 | output |
+|---------|-----------|------------|------------|--------|
+| T1      | T1_mbr1   | Y          | Y          | Y      |
+| T1      | T1_mbr2   | Y          | Y          | Y      |
+| T1      | T1_mbr3   | Y          | Y          | Y      |
+| T1      | T1_mbr4   | Y          | Y          | Y      |
+| T1      | T1_mbr5   | Y          | N          | N      |
+| T2      | T2_mbr1   | Y          | Y          | N      |
+| T2      | T2_mbr2   | Y          | N          | N      |
+| T2      | T2_mbr3   | N          | Y          | N      |
+| T2      | T2_mbr4   | N          | N          | N      |
+| T2      | T2_mbr5   | N          | N          | N      |
+| T3      | T3_mbr1   | Y          | Y          | Y      |
+| T3      | T3_mbr2   | Y          | Y          | Y      |
+| T3      | T3_mbr3   | N          | Y          | N      |
+| T3      | T3_mbr4   | N          | Y          | N      |
+| T3      | T3_mbr5   | Y          | N          | N      |
+
+
+
+
+### Solution Query
+
+```sql
+WITH criteria_check as (
+    SELECT *, CASE WHEN criteria_1='Y' and criteria_2='Y' THEN 1 ELSE 0 END as criteria_flag
+    FROM   data
+),
+criteria_summary AS (
+    SELECT *, SUM(criteria_flag) OVER(PARTITION BY team_id) as flag_sum
+    FROM   criteria_check
+)
+SELECT team_id, 
+       member_id, 
+       criteria_1, 
+       criteria_2,
+       CASE WHEN criteria_flag=1 and flag_sum>=2 THEN 'Y' ELSE 'N' END as output
+FROM   criteria_summary
+
+
+-- NOTE: solve in first attempt
+```