PSLine2000Documentation/Queries/materialSelect.md

materialSelect

Analysis generated on: 4/2/2025 10:03:37 AM

SQL Statement

SELECT DISTINCTROW Process.*
FROM Process;

Dependencies

• None

Parameters

• None

What it does

SQL Code Description

Overview

The provided SQL code uses the SELECT statement to retrieve unique data from the Process table. The query aims to extract all distinct rows from the table, excluding any duplicate records.

Breakdown

Key Components:

• SELECT DISTINCTROW: This clause is used to select only unique rows from a table. Unlike the SELECT DISTINCT statement, which returns a list of values that appear in multiple rows, DISTINCTROW ensures that all columns (*) from each row are returned uniquely.
• FROM Process: Specifies the table (Process) from which data is to be retrieved.

How it Works:

1. When you run this query, SQL Server selects one unique row from the specified table and returns its entire row as a result set.
2. Since SELECT DISTINCTROW only returns one row per column combination, no duplicate rows are included in the result set.
3. The returned data will contain all columns (*) present in the original Process table.

Implications:

• Data Loss: If you have multiple identical rows with different values for some columns (due to constraints like primary keys or unique indexes), this query might return an empty result set, as SQL Server cannot determine which row(s) should be returned.
• Query Performance: This operation can be resource-intensive and may impact performance if the table is large.

Best Practice:

Use SELECT DISTINCTROW when you need to ensure that each record has a unique combination of values for all columns in a specific context (e.g., reporting, analytics). However, consider using SELECT DISTINCT instead, as it's more efficient and suitable for most use cases.