# Query14
Analysis generated on: 4/2/2025 10:09:05 AM
---
## SQL Statement
```sql
SELECT Process.PartNumber, Process.PartName, Process.ActualPartHeight, Process.ActualPartWidth, IIf([ActualPartHeight]>=19 Or [ActualPartWidth]>=19,"Y","N") AS [Check]
FROM PartsToQuery LEFT JOIN Process ON PartsToQuery.PNwRev = Process.PartNumber
WHERE (((IIf([ActualPartHeight]>=19 Or [ActualPartWidth]>=19,"Y","N"))="Y"));

```
## Dependencies
- [[Tables/PartsToQuery]]
- [[Tables/Process]]
## Parameters
- *None*
## What it does
**SQL Code Explanation**
==========================

### Overview

This SQL query retrieves data from two tables: `PartsToQuery` and `Process`. The query joins the two tables on a common column, filters results based on a conditional check, and selects specific columns for each row.

### Column Selection

The query selects four columns from the `Process` table:

*   `PartNumber`: a unique identifier for each part
*   `PartName`: the name of the part
*   `ActualPartHeight`: the actual height of the part
*   `ActualPartWidth`: the actual width of the part

### Conditional Check

The query applies an IIF (Conditional Expression) check to the `ActualPartHeight` and `ActualPartWidth` columns. If either column is greater than or equal to 19, the expression returns "Y", otherwise it returns "N".

This condition is used in two places:

*   The first occurrence of `IIf` checks if there are any rows where the condition is true (`[ActualPartHeight]\u003e=19 Or [ActualPartWidth)\u003e=19="Y"`).
*   The second occurrence of `IIf` filters the results to only include rows where the condition is true.

### Join and Filter

The query joins the `PartsToQuery` table with the `Process` table on the `PNwRev` column, which matches the `PartNumber` in both tables.

However, the filtering condition uses a self-referential clause that's unlikely to produce meaningful results. Since it filters by rows where the condition is true, there will only be one row left if any conditions are met, making this part of the query potentially confusing and inefficient.

### Query Improvement Suggestions

*   Simplify the filtering condition using `IN` or `EXISTS`, as it's not clear why you'd want to use an IIF function here.
*   Use a proper JOIN instead of an explicit LEFT JOIN with a filter condition, which can lead to unexpected results.
*   Consider indexing the columns involved in the WHERE clause to improve performance.

### Sample Output

| PartNumber | PartName  | ActualPartHeight | ActualPartWidth | Check |
|------------|-----------|------------------|-----------------|-------|
| ...        | ...       | ...              | ...             | Y     |

Note that the actual output will depend on the data in the `PartsToQuery` and `Process` tables.