Data Aggregation with SQL: Summing Quantity by Date in SQL Server 2008

Transforming a Table with Column Names as Values for Phone Numbers

Understanding How to Optimize Slow SELECT Statements Using fn_decompress in SQL Server

Avoiding Ambiguous Rows When Joining Multiple Tables with Conditional Aggregation

Mastering Subqueries and Correlated Queries: A SQL Guide for Efficient Data Retrieval

Understanding SQL Database Structures and Column Lengths for Optimized Performance and Data Integrity

Counting Distinct Records in SQL Databases Using GROUP BY, HAVING, and DISTINCT

How to Sum Columns from Two Tables with Conditions Using SQL Server

How to Extract OLAP Metadata from SQL Server Linked Servers Without Errors

Conditional GROUP BY with Dynamic Report IDs Using T-SQL in Stored Procedures