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sql-encoder

A SQL string escaper produces a safely-quotable string literal for inclusion in a SQL statement — replacing single quotes with the dialect-correct doubled or backslashed form, handling backslashes, NUL bytes, newlines, and other special characters that vary by database (MySQL backslash escapes, PostgreSQL standard-conforming strings, SQLite quote-doubling). The ZTools SQL Encoder is for generating safe ad-hoc query strings for migrations, debugging, or one-off tooling. It is NOT a substitute for parameterised queries in production code — always use prepared statements with bind parameters as the primary defence against SQL injection.

Use cases​

Ad-hoc data migrations​

A one-off CSV-to-SQL conversion. Escape each value before composing INSERT statements; load via psql / mysql client.

Debugging by hand-crafted query​

Reproducing an issue with specific input that contains apostrophes or backslashes. Escape correctly so the manual query runs without a syntax error.

Generating seed scripts​

Test fixtures with multilingual content (apostrophes, accented characters, smart quotes). Escape into safe SQL literals.

Reporting tools that emit SQL​

A reporting harness builds queries dynamically. Escape input values rather than concatenating raw strings.

How it works​

  1. Pick the dialect — MySQL, PostgreSQL, SQLite, MSSQL, Oracle. Each escapes slightly differently.
  2. Paste the raw string — Whatever you want to embed inside single-quoted SQL literals.
  3. Encode — Apply dialect-specific rules: PostgreSQL doubles single quotes (''); MySQL with backslash mode replaces with \\'; SQLite always doubles.
  4. Wrap in quotes — Optionally produce the full quoted literal '...' ready to paste into a query.
  5. Copy — Output to clipboard. Always paste into a query you control — never use generated SQL with untrusted input in production.

Examples​

Input: O'Reilly (PostgreSQL)

Output: O''Reilly

Input: Hello\nWorld (MySQL)

Output: Hello\\nWorld

Input: Standard-conforming PostgreSQL with E'\\'

Output: E'\\\\' literal

Frequently asked questions​

Should I use this in production?

No. Production code MUST use parameterised queries (prepared statements with bind parameters). The escaper is for one-off scripts and debugging; even slightly wrong escapes lead to SQL injection.

Why do dialects escape differently?

Historical accident. PostgreSQL's standard-conforming strings double the quote (''). MySQL added backslash escapes for C-style strings. SQLite doubles. Dialect-specific encoding is the only safe default.

Does it handle NUL bytes?

PostgreSQL forbids NUL in TEXT columns; MySQL escapes as \\0. The encoder warns when NUL bytes are present.

What about Unicode / emoji?

Most modern databases store Unicode natively as UTF-8. Pass through as-is unless the database encoding is non-UTF-8.

How do I generate parameterised queries?

Outside this tool — your language's database driver provides bind-parameter APIs (e.g. ? placeholders + array of values). The escaper is only for direct-string-injection contexts.

Are stored-procedure call arguments different?

They use the same string-literal rules. Bind parameters are still preferred where supported.

Tips​

  • Default to parameterised queries — the escaper is for ad-hoc tooling only.
  • Pick the right dialect. MySQL escapes are wrong on PostgreSQL and vice-versa.
  • For multi-line strings, use the dialect's string literal escapes (\\n MySQL, chr(10) PostgreSQL's standard mode).
  • After generating, paste into a SQL editor first and run EXPLAIN — verify the syntax is right before running on real data.
  • Document any generated SQL clearly — readers may not realise values came from a templating step.

Try it now​

The full sql-encoder runs in your browser at https://ztools.zaions.com/sql-encoder — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-05 · Author: Ahsan Mahmood · Edit this page on GitHub