Library of Useful (Difficult) SQL scripts

You may find this wiki on LessThanDot useful, for the most part, it is by Denis Gobo, Microsoft SQL MVP.

EDIT: The wiki includes 100+ SQL Server Programming Hacks, the list is, I think, too long to include here, however, there is a comprehensive index.

Also available from the same site: SQL Server Admin Hacks.

Here are a few that I find very useful:

• SQL Server Best Practices - Microsoft SQL Server White Papers and Best Practices
• vyaskn - A mixture of articles From DBA to Developer
• Backup, Integrity Check and Index Optimization
• SQLServerCentral Scripts - Scripts for most most DBA tasks and more
• Script Repository: SQL Server 2005 - TechNet Script Center
• Scripts and Tools for Performance Tuning and Troubleshooting SQL Server 2005
• SQL Server Query Processing Team - Hardcore advice from the MS SQL optimisation team
• Common Solutions for T-SQL Problems
• Davide Mauri's Index Scripts

Some Administration stuff

Glenn Berry: Five Very Useful Index Selection Queries for SQL Server 2005

• Find "Missing" Indexes for the entire instance of SQL Server
• Find "Missing" Indexes for a single table
• Examine the current index structure for a single table
• Look at index usage for a single table
• Look for possible bad indexes inside the entire current database
• Drill into your workload (Bonus)

SQL Server Central: Seven Monitoring Scripts

• Failed jobs report
• Free space by drive
• Disabled jobs
• Running jobs
• Server role members
• Last backup date
• SQL Log

And last, but not least this resource: SQL Server Programming Hacks - 100+ List

Joe Celko's SQL Puzzles and Answers

The Art of SQL (slight Oracle bias)

Sql Cookbook has a variety of interesting example, though some will undoubtedly be unsupported by your RDBMS of choice. O'Reilly also has a T-SQL Cookbook, but I've never personally read it.

directly from MS Script Repository: SQL Server 2005: http://www.microsoft.com/technet/scriptcenter/scripts/sql/sql2005/default.mspx?mfr=true

Nigel's very usefull stuff: http://www.nigelrivett.net/#TransactSQL

Forgive me for the self-advertising, but I have posted a few on my blog (http://progblog.wordpress.com) because I'm rubbish at SQL and it's a good place to store things I know I'll need in the future :-) If anyone has anything more substantial then please post, I'm as keen as anyone to get hold of something like this!

I would guess that a copy of the "SQL Cookbook" would help too.

I've had some use of these SQL "hacks" for Oracle a couple of times.

Concatenate as grouping function

In query data generation for joining purposes

Here is another link for SQL Server: best practices - dozens of script examples

http://www.sqlusa.com/bestpractices2005/

Check Out SQLCAT.com (MS SQL BEST PRACTICES TEAM)

Riffing off the Celko answer: SQL For Smarties. This has great in depth chapters that will augment the SQL Puzzles book. Also there is another Celko book I just learned of named Joe Celko's Trees and Hierarchies in SQL for Smarties.