Yes — a good SQL formatter supports multiple database dialects, and the InventiveHQ SQL Formatter handles MySQL, PostgreSQL, SQL Server (T-SQL), Oracle (PL/SQL), SQLite, BigQuery, Redshift, and Snowflake. You select the dialect before formatting so the tool knows which words are reserved keywords and which identifier-quoting style — backticks, double quotes, or square brackets — to leave untouched. A formatter re-indents and re-cases your query without changing its meaning; picking the wrong dialect is what causes it to touch something it shouldn't, like uppercasing a word your database treats as an ordinary column name.
That's the summary an AI gives you. Here's what it can't show you: the specific places where MySQL, PostgreSQL, SQL Server, and Oracle actually diverge — the row-limiting clauses, quoting rules, and concatenation operators that make a query "just work" on one engine and throw a syntax error on the next. Below is the concrete dialect map, a live formatter you can paste into right now, and the one rule that separates formatting from translation.
Formatting is not translation
This is the distinction almost every dialect question actually hinges on, so it's worth nailing first.
A formatter rearranges whitespace, indentation, and keyword casing. It parses your SQL and prints it back out prettier. It never rewrites syntax. LIMIT 10 stays LIMIT 10. Backtick-quoted `user_id` stays in backticks. Dialect awareness only tells the formatter which tokens are keywords worth capitalizing and which quoting characters to respect.
A translator (a separate tool — try the SQL Dialect Translator) rewrites the syntax itself: MySQL's LIMIT 10 becomes SQL Server's TOP 10 or Oracle's FETCH FIRST 10 ROWS ONLY. That is a semantic transformation, not a cosmetic one.
If you paste MySQL into a formatter and select "SQL Server," you do not get runnable T-SQL. You get MySQL that is now indented and capitalized — and still full of MySQL-only syntax. Choose the dialect that matches the SQL you pasted, not the database you wish you were targeting.
The dialect map: where MySQL, PostgreSQL, SQL Server, and Oracle disagree
These are the five differences that account for most "works here, breaks there" errors. Knowing them tells you which dialect a query is written in — and which one to select in the formatter.
| Feature | MySQL | PostgreSQL | SQL Server (T-SQL) | Oracle (PL/SQL) | SQLite |
|---|---|---|---|---|---|
| Limit rows | LIMIT 10 | LIMIT 10 | SELECT TOP 10 | FETCH FIRST 10 ROWS ONLY (12c+) or ROWNUM | LIMIT 10 |
| Quote an identifier | `col` (backticks) | "col" (double quotes) | [col] (brackets) | "col" (double quotes) | "col" or `col` |
| Auto-increment key | AUTO_INCREMENT | SERIAL / GENERATED … AS IDENTITY | IDENTITY(1,1) | sequence + .NEXTVAL or GENERATED … AS IDENTITY | AUTOINCREMENT |
| Concatenate strings | CONCAT(a,b) | a || b | a + b | a || b | a || b |
| Current timestamp | NOW() | NOW() / CURRENT_TIMESTAMP | GETDATE() | SYSDATE / CURRENT_TIMESTAMP | CURRENT_TIMESTAMP |
| Case-insensitive match | LIKE (default collation) | ILIKE | LIKE (collation-dependent) | LIKE + UPPER() | LIKE (ASCII only) |
| Which should I pick in the formatter? | Query uses backticks or LIMIT | Query uses ||, ILIKE, or RETURNING | Query uses [brackets] or TOP | Query uses SYSDATE, NVL, or FETCH FIRST | Lightweight, no server-only keywords |
Two clues identify a dialect almost instantly: the quoting character (backticks → MySQL, brackets → SQL Server, double quotes → PostgreSQL/Oracle) and the row-limit clause (LIMIT → MySQL/PostgreSQL/SQLite, TOP → SQL Server, FETCH FIRST/ROWNUM → Oracle). Match those, and you have the dialect to select.
Try it: format your query below
Paste a query, choose the dialect that matches it, and format. The tool runs entirely in your browser — nothing is uploaded — so it's safe for work-in-progress queries (still strip real credentials and customer data first).
Why the dialect setting actually matters
It looks cosmetic, but two things go wrong when the dialect is mismatched:
- Reserved-word casing. Each engine has its own reserved-word list. A formatter capitalizes keywords. If it thinks
rankoruseris a keyword when your schema uses it as a plain column name, the uppercased result can read confusingly (and, in edge cases with case-sensitive collations, behave differently). The right dialect gives the formatter the right keyword list. - Identifier quoting. A PostgreSQL-mode formatter doesn't expect backticks; a MySQL-mode formatter doesn't expect brackets. Feeding one the other's quoting can cause it to misparse where an identifier ends, breaking indentation around that clause.
Formatting itself never changes what a valid query does — databases discard insignificant whitespace before planning, so the execution plan is identical (see does SQL formatting change query execution). The dialect setting only governs what the formatter treats as syntax versus data.
The one thing you must never reformat
Whitespace outside a string literal is layout the database ignores. Whitespace inside a quoted string literal is data. Reformatting collapses or reindents it at your peril:
-- Safe to reformat: whitespace between tokens is ignored
SELECT id, name FROM users WHERE active = 1;
-- DO NOT reformat the literal — the spaces are part of the value
UPDATE config SET banner = 'Welcome to the portal';
A dialect-aware formatter knows the difference and leaves literal contents alone. A naive find-and-replace "prettifier" does not — which is why regex-based reformatting of SQL is risky. Use a real parser.
Common questions in one place
- Does it convert dialects? No — that's a translator, use the SQL Dialect Translator.
- Does formatting change results or performance? No — whitespace and casing outside literals are semantically invisible.
- Can it fix a broken query? Not reliably — it parses valid SQL; on a real error it stops or leaves that section unformatted, which helps you locate the error but won't repair it. See can a SQL formatter fix syntax errors.
- Is it safe with production SQL? Yes if it's client-side (this one is), but scrub credentials and customer data first.
Bottom line
Multi-dialect support means the formatter respects each engine's quoting and keyword rules — not that it rewrites your query for another database. Pick the dialect that matches the SQL you're pasting (read the quoting characters and row-limit clause to identify it), format, and you get clean, runnable code for that engine. When you genuinely need to move a query between engines, reach for a translator, not a formatter.