SQL Server 2025 Regex Support: Native T-SQL Expressions

SQL Server 2025 && Regex = Less Code, Less Pain in your queries

Hi Guys,

Here’s some good news: after years of workarounds, hacks, and tricks, SQL Server 2025 finally ships with native regex support in T-SQL. And no, this isn’t just a nice-to-have. It’s a game changer for anyone who deals with messy data, phone numbers, emails, codes… you name it.

For years we’ve had to rely on ugly patterns like LIKE '%...%', CHARINDEX, SPLIT, or even external CLR functions. They worked, but the cost in complexity, performance, and bugs was too high.

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Finally: native regex in SQL Server 2025

That’s right. Now you get built-in functions such as:

• REGEXP_LIKE(...)
• REGEXP_REPLACE(...)
• REGEXP_SUBSTR(...)
• REGEXP_COUNT, REGEXP_SPLIT_TO_TABLE, REGEXP_INSTR, REGEXP_MATCHES (table-valued functions are rolling out too)

All powered by the RE2 engine: fast, familiar, and compatible enough with PCRE and .NET regex syntax.

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What changes?

1. Parsing complex strings in plain T-SQL — finally readable.
2. Less code, fewer bugs.
3. Good performance, but keep in mind: for simple patterns like LIKE 'abc%', the old operators are still faster.

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A practical example: validating phone numbers

Let’s say we’ve got a PhoneNumber column, and we want to select only the valid ones:

• Italian numbers (+39 345 1234567)
• National with or without separators
• Filter out the garbage

With native regex:

-- filter only valid numbers
SELECT *
FROM Customers
WHERE REGEXP_LIKE(
  PhoneNumber,
  '^(\+39\s?)?3\d{2}[\s\/]?\d{6,7}$',
  'i'
);

• ^(\+39\s?)? → optional country code with spaces
• 3\d{2} → Italian mobile prefix
• [\s\/]? → optional space or slash
• \d{6,7} → 6–7 digit number
• 'i' → case-insensitive flag

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Clean the number (digits only)

SELECT
  REGEXP_REPLACE(
    PhoneNumber,
    '[^\d+]',
    '',
    1,
    0,
    'g'
  ) AS PurePhone
FROM Customers;

Here g (global replace) removes everything except digits and +.

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Extract the number directly

SELECT
  REGEXP_SUBSTR(
    PhoneNumber,
    '(\+?39\s?)?3\d{2}\d{6,7}',
    1,
    1,
    '',
    0
  ) AS MatchedNumber
FROM Customers;

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Why is this a real breakthrough?

• No more ugly nested functions.
• Regex patterns are readable and maintainable.
• Validation happens in-database, avoiding round-trips to the app.

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Quick wrap-up

SQL Server 2025 finally gives us native regex. It feels like a modern feature, but now it’s core SQL Server.

Use it wisely (regex can be expensive), but whenever you need advanced filtering or validation — it’s the right tool.

If you’re interested, I can prepare a follow-up post on regex & index tuning, showing how to normalize strings first so your queries still benefit from indexes.

Stay tuned and keep performance tight!

Luca