SQL Server Structure on SQL Server Scripts

SQL Server Find Columns by Data Type Across the Database

Fri, 22 May 2026 00:00:00 +0000

"Where is every datetime column?" — "Which tables still use text instead of varchar(max)?" — "Are any columns using a deprecated user-defined type?" These are recurring DBA questions during schema audits, deprecation sweeps, and pre-migration assessments. This T-SQL script joins sys.columns to sys.types, sys.tables, and sys.schemas to produce the canonical answer: every column in the current database with its full type signature.

Purpose and Overview

Which columns survived the move from text to varchar(max)? Which fields still carry the deprecated Money_T UDT three releases after it was officially retired? Did a recent merge silently reintroduce datetime on a column the design review thought it had migrated to datetime2? A single catalog-view query against sys.columns and sys.types answers all three — and every other question of the form "where is every column of type X in this database?" — without an INFORMATION_SCHEMA round trip or a manual table-by-table sweep.

SQL Server List All Foreign Keys with Referenced Tables

Thu, 21 May 2026 00:00:00 +0000

Every database with foreign keys eventually needs a single inventory: every constraint, its parent table and column, and the referenced table and column on the other side. This T-SQL script joins sys.foreign_keys to sys.foreign_key_columns, sys.tables, and sys.columns to produce the canonical foreign-key map of the current database — one row per column in every multi-column foreign key.

Purpose and Overview

The first symptom that a referential boundary has slipped is usually subtle: a DELETE on a parent table that ran in seconds last quarter now takes minutes, or a join across the foreign key plans an unexplained scan on the child side. Almost every diagnosis trails back to the same short list — a constraint disabled by an unattended deployment, a NOT TRUSTED flag left behind by a WITH NOCHECK bulk load, or a duplicate FK shadowing the one the optimizer was relying on. The inventory query below — sys.foreign_keys joined to sys.foreign_key_columns, sys.tables, and sys.columns — produces the complete relationship map in a single pass, so the foreign key in question is one filter away.

SQL Server Foreign Keys Without Indexes Script

Sat, 18 Apr 2026 00:00:00 +0000

Foreign keys enforce referential integrity, but SQL Server does not automatically create indexes on the referencing (child) columns. An unindexed foreign key column forces a full table scan every time a join or a DELETE on the parent table triggers a referential check. This script identifies all foreign key columns in the current database that have no supporting index, and generates the CREATE INDEX statements to fix them.

Purpose and Overview

When you run a DELETE on a parent table, SQL Server must verify that no child rows reference the deleted parent. If the child table's foreign key column has no index, SQL Server performs a full table scan on the child table for every deleted parent row. On large tables this can make simple deletes extremely slow and cause blocking on the child table.

SQL Server: Find Tables Without Primary Keys

Thu, 16 Apr 2026 00:00:00 +0000

Tables without primary keys are heap structures with no guaranteed row ordering and no unique row identifier. They cause full table scans in queries that could use seeks, slow down DELETE and UPDATE operations, and are incompatible with SQL Server replication and Change Data Capture. This script finds every user table in the current database that has no primary key defined.

Purpose and Overview

A primary key enforces uniqueness on a column or set of columns and, by default, creates a clustered index that physically orders the table rows. Without a primary key, SQL Server stores rows in a heap: an unordered structure where updates and deletes must first locate rows through a full scan or a nonclustered index lookup followed by a separate heap RID lookup.

sp_pkeys: SQL Server Primary Key Discovery Script

Sat, 09 Aug 2025 00:00:00 +0000

SQL Server Primary Key Discovery Script Using sp_pkeys and sysobjects

Purpose

This SQL Server script generates dynamic SQL statements that can be executed to discover primary keys across all user tables in a database. It's a powerful administrative tool that helps database administrators quickly identify primary key constraints without manually checking each table individually.

Code Breakdown

1select 'select "Processing Table ' + name + '"go' + ' sp_pkeys ' + name + 'go'
2from sysobjects
3where type = 'U'
4order by name

Let's break down each component of this query:

SQL Server: Find Tables with Clustered Indexes for Rebuild

Sat, 09 Aug 2025 00:00:00 +0000

SQL Server Query to Identify Tables with Clustered Indexes for Rebuilding

Database administrators frequently need to perform maintenance operations on clustered indexes to optimize database performance. This SQL Server query provides a quick and efficient way to identify all user tables that contain clustered indexes, which is typically the first step in a comprehensive index rebuilding strategy.

The SQL Query

1select distinct a.name
2from sysobjects a, sysindexes b
3where a.type = 'U'
4 and a.id = b.id
5 and b.indid = 1
6order by a.name

Purpose and Use Case

This query serves as a foundation script for database maintenance operations, specifically designed to: