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How do I do a simple 'Find and Replace' in MsSQL?

sql
best-practices
sql-queries
error-handling
Alex KataevbyAlex Kataev·Aug 26, 2024
TLDR

Perform a swift 'Find and Replace' in MS SQL Server by using an UPDATE statement partnered with REPLACE:

UPDATE your_table SET your_column = REPLACE(your_column, 'find_this', 'replace_with_this') WHERE your_column LIKE '%find_this%';

You need to swap 'find_this' and 'replace_with_this' with your text. The LIKE condition ensures that only rows containing 'find_this' are updated.

Preparing for the operation

Before firing up the SQL cannon, here are some guiding principles:

  • Backup: Need I say more? Your data calls for a crusader.
  • Transactions: Your safety net in the SQL rope walk.
  • Test Environment: Experiment away from the live battleground.
  • Security: Love thy data? Use parameterized queries.
  • Data integrity: Can't forget our friends in foreign key land.
  • Data Type: If your REPLACE doesn't play with your data type, consider a little casting magic.
  • Pattern Matching: Use LIKE, but with love and care.
  • CLR Integration: For the Shakespeare of Patterns, CLR functions could be your lifeline.

Trouble in paradise? Here's your shield!

Encountered some dragons along the way? Here's how you slay them:

The special characters debacle

Are special or wildcard characters flying around? Let's ground them with proper escaping.

The dynamic conundrum

Got to build dynamic SQL statements? Doomsday won't come with QUOTENAME.

Error taming

Arm yourself with a TRY...CATCH shield to capture and defeat errors.

Multi-table operations

Are different tables calling out for help? Hear them with INFORMATION_SCHEMA.TABLES and INFORMATION_SCHEMA.COLUMNS.

What to do when things get, well, complicated!

When complexity rises, keep calm and follow these best practices:

Temporary tables to the rescue

Navigating a sea of updates? A lifeboat named "temporary tables" might save you.

Multi-database operations

Are various databases waving for help? Set the course towards them, excluding system databases of course.

Custom functions for a custom world

When REPLACE seems too ordinary, write custom CLR functions. Unleash the inner Tolkien, and create your own Regular Expressions (RegEx-land).