--- title: "strip_accents" slug: "dev-database-reference-sql-functions-string-strip-accents" updated: 2026-10-30T18:18:56Z published: 2026-10-30T18:18:56Z canonical: "docs.vastdata.com/dev-database-reference-sql-functions-string-strip-accents" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt > Use this file to discover all available pages before exploring further. # strip_accents *Applies to VAST Cluster 5.5.* *[Functions](/develop/docs/dev-database-reference-sql-functions-index) β€Ί [Text basics](/develop/docs/dev-database-reference-sql-functions-string-text-basics) β€Ί Unicode and URLs.* Removes accents and other combining marks from the letters of a string, so `Crème Brûlée` becomes `Creme Brulee`. It has no aliases. ## Syntax ``` strip_accents(s) ``` | Argument | Type | Description | | --- | --- | --- | | `s` | `VARCHAR` | The string to remove accents from. | **Returns:** `VARCHAR`. **Aliases:** none. ## Set up the examples The examples connect with the ADBC driver, as in [VAST Query Engine (ADBC)](/develop/docs/dev-database-integrations-adbc), and work in a schema called `docs_sql_fn_strip_accents`. Set `QE_ENDPOINT`, `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY` and `VASTDB_BUCKET` ([SQL reference](/develop/docs/dev-database-reference-sql-index#example-connect-and-use-a-transaction)), and run the blocks in order in one Python session. Below each block is the output you should see. This block connects, defines the `run()` and `plan()` helpers, and creates a table of cities. `Málaga` is written decomposed, with a combining accent; the last row has no city: ``` import os import re import adbc_driver_manager import adbc_driver_manager.dbapi as dbapi import adbc_driver_vastdb BUCKET = os.environ["VASTDB_BUCKET"] SCHEMA = f'"{BUCKET}/docs_sql_fn_strip_accents"' conn = dbapi.connect( driver=adbc_driver_vastdb.get_driver_path(), db_kwargs={ "vast.db.endpoint": os.environ["QE_ENDPOINT"], "vast.db.access_key": os.environ["AWS_ACCESS_KEY_ID"], "vast.db.secret_key": os.environ["AWS_SECRET_ACCESS_KEY"], }, autocommit=True, ) def server_message(e): """The server's message in a driver error, without the request ID or the echoed statement.""" text = re.sub(r"\[req=0x[0-9a-f]+\]: ", "", str(e)) found = (re.search(r'message: "(.*?)", request_id', text, re.S) or re.search(r"description: (.*)\)", text, re.S)) message = found.group(1) if found else text.strip().splitlines()[-1] message = re.sub(r"^Plan query: '.*?' failed with: ", "", message, flags=re.S) message = re.split(r"\\n|\n", message)[0].replace('\\"', '"') return message.replace(BUCKET, "") def run(sql): """Run one statement. Print the rows it returns, or the error.""" try: with conn.cursor() as cur: cur.execute(sql) rows = cur.fetchall() if cur.description else [] except (adbc_driver_manager.Error, OSError) as e: print(f"{type(e).__name__}: {server_message(e)}") else: print(rows) def plan(sql): """Print the plan without its ~N Rows lines: the table's row count, which can still be 0 just after an insert.""" with conn.cursor() as cur: cur.execute("EXPLAIN " + sql) steps = cur.fetchall()[0][1] print("\n".join(line for line in steps.splitlines() if "Rows" not in line)) TABLE = f"{SCHEMA}.cities" run(f"CREATE SCHEMA IF NOT EXISTS {SCHEMA}") run(f"CREATE TABLE IF NOT EXISTS {TABLE} (id BIGINT, city VARCHAR, country VARCHAR)") run(f"INSERT INTO {TABLE} VALUES " "(1, 'Z\u00fcrich', 'CH'), " "(2, 'Krak\u00f3w', 'PL'), " "(3, '\u0141\u00f3d\u017a', 'PL'), " "(4, 'Ma\u0301laga', 'ES'), " "(5, 'Zurich', 'CH'), " "(6, NULL, 'FR')") ``` ``` [] [] [(6,)] ``` ## What it does `strip_accents` returns the string with the accents taken off its letters. Everything else is kept: case, spaces, and characters that have no accent, such as emoji and `ẞ`. It removes the marks that Unicode can write as a separate combining accent on a base letter: acute, grave, circumflex, diaeresis, ring, and so on. It works on both forms of an accented letter, precomposed (`é`, one code point) and decomposed (`e` followed by a combining accent, written `'e\u0301'` on this page): | Call | Result | | --- | --- | | `strip_accents('Crème Brûlée')` | `'Creme Brulee'` | | `strip_accents('Ångström')` | `'Angstrom'` | | `strip_accents('café')` | `'cafe'` | | `strip_accents('e\u0301')` (decomposed) | `'e'` | | `strip_accents('É')` | `'E'`: case is kept | | `strip_accents('a1-b2!')` | `'a1-b2!'`: digits and punctuation are kept | Letters that Unicode treats as letters in their own right, not as a base letter with an accent, are kept: | Call | Result | | --- | --- | | `strip_accents('Łódź')` | `'Łodz'`: `ó` and `ź` lose their accents; `Ł` (L with a stroke) is kept | | `strip_accents('ø')` | `'ø'` | | `strip_accents('ß')` | `'ß'` | | `strip_accents('đ ħ æ œ ı')` | `'đ ħ æ œ ı'`: letters with a stroke, ligatures and the dotless `ı` are kept | If you need those letters replaced too, follow `strip_accents` with [replace](/develop/docs/dev-database-reference-sql-functions-string-replace) or [translate](/develop/docs/dev-database-reference-sql-functions-string-translate), for example `translate(strip_accents(s), 'Łłø', 'Llo')`. ## NULLs and edge cases | Input | Result | | --- | --- | | `NULL` | `NULL` | | `''` (empty string) | `''` | | `'e\u0301'` (e and a combining accent) | `'e'` | | `'e\u0301 🇫🇷 ẞ'` | `'e 🇫🇷 ẞ'` | | `'ß'`, `'ø'` | unchanged | | A number, decimal, date, boolean, `BLOB` or list | Error: `No function matches the given name and argument types` | The same cases, as the cluster returns them. They use the table and helpers from [Set up the examples](/develop/docs/dev-database-reference-sql-functions-string-strip-accents#set-up-the-examples): ``` run("SELECT strip_accents(NULL), strip_accents(''), strip_accents('e\u0301'), strip_accents('e\u0301 πŸ‡«πŸ‡· ẞ'), " "strip_accents('\u00df'), strip_accents('\u00f8')") run("SELECT strip_accents('Cr\u00e8me Br\u00fbl\u00e9e'), strip_accents('\u00c5ngstr\u00f6m'), " "strip_accents('\u0141\u00f3d\u017a')") run("SELECT strip_accents(123)") ``` ``` [(None, '', 'e', 'e πŸ‡«πŸ‡· ẞ', 'ß', 'ΓΈ')] [('Creme Brulee', 'Angstrom', 'Łodz')] InternalError: Binder Error: No function matches the given name and argument types 'strip_accents(INTEGER_LITERAL)'. You might need to add explicit type casts. ``` ## Examples Each city with its accents removed. The precomposed letters of rows 1 to 3 and the combining accent of row 4 are all removed; the `Ł` of row 3 is kept: ``` run(f"SELECT id, city, strip_accents(city) FROM {TABLE} ORDER BY id LIMIT 10") ``` ``` [(1, 'ZΓΌrich', 'Zurich'), (2, 'KrakΓ³w', 'Krakow'), (3, 'ŁódΕΊ', 'Łodz'), (4, 'MΓ‘laga', 'Malaga'), (5, 'Zurich', 'Zurich'), (6, None, None)] ``` Search without regard to accents: `Zurich` finds both spellings of the city: ``` run(f"SELECT id, city FROM {TABLE} WHERE strip_accents(city) = 'Zurich' ORDER BY id LIMIT 10") ``` ``` [(1, 'ZΓΌrich'), (5, 'Zurich')] ``` Search without regard to accents or case, by combining it with [lower](/develop/docs/dev-database-reference-sql-functions-string-lower): ``` run(f"SELECT id, city FROM {TABLE} WHERE lower(strip_accents(city)) = 'krakow' ORDER BY id LIMIT 10") ``` ``` [(2, 'KrakΓ³w')] ``` ## How it runs in VAST The Query Engine runs on the cluster's CNodes, and a query on a table starts with a scan in VAST DataBase (`VAST_SCAN`). VAST DataBase can evaluate a comparison of a column with a constant, but not a function of a column, so `strip_accents()` is always computed by the Query Engine: - **In the `SELECT` list,** the scan reads the column and the Query Engine computes `strip_accents()` for each row it returns. - **In `WHERE`,** the scan sends the column for every row, and a `FILTER` step in the Query Engine computes `strip_accents()` and keeps the rows that match. No rows are skipped in storage. `COLLATE noaccent` uses the same function: `city COLLATE noaccent = 'Zurich'` becomes a `strip_accents(city) = 'Zurich'` filter, so it isn't pushed down either. See [COLLATE nocase and noaccent](/develop/docs/dev-database-reference-sql-functions-string-collate). The plan of the `WHERE` example shows the `FILTER` step above the scan: ``` plan(f"SELECT id FROM {TABLE} WHERE strip_accents(city) = 'Zurich'") ``` ``` β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β” β”‚ PROJECTION β”‚ β”‚ ──────────────────── β”‚ β”‚ #1 β”‚ β”‚ β”‚ β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”¬β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜ β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”΄β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β” β”‚ FILTER β”‚ β”‚ ──────────────────── β”‚ β”‚ (strip_accents(city) = β”‚ β”‚ 'Zurich') β”‚ β”‚ β”‚ β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”¬β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜ β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”΄β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β” β”‚ VAST_SCAN β”‚ β”‚ ──────────────────── β”‚ β”‚ Function: VAST_SCAN β”‚ β”‚ β”‚ β”‚ Projections: β”‚ β”‚ city β”‚ β”‚ id β”‚ β”‚ β”‚ β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜ ``` ## Make it faster - **Store a search key.** If you search without regard to accents often, store the accent-free form (for example `lower(strip_accents(city))`, computed by your application when it writes the rows) in its own column. A comparison of that raw column with a constant is pushed down to VAST DataBase, so rows that don't match never leave storage. The plan for `city = 'Zurich'` has no `FILTER` step: ``` plan(f"SELECT id FROM {TABLE} WHERE city = 'Zurich'") ``` ``` β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β” β”‚ VAST_SCAN β”‚ β”‚ ──────────────────── β”‚ β”‚ Function: VAST_SCAN β”‚ β”‚ Projections: id β”‚ β”‚ β”‚ β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜ ``` - **Combine it with a pushed-down condition.** In `country = 'PL' AND strip_accents(city) = 'Krakow'`, `country = 'PL'` is still evaluated in VAST DataBase, so `strip_accents()` runs only on the rows that pass it. ## Limitations and errors - **Strings only.** A number, decimal, date, boolean, `BLOB` or list fails with `No function matches the given name and argument types`. - **Accents only.** Letters such as `Ł`, `ø`, `đ`, `æ` and `ß` are kept. See [What it does](/develop/docs/dev-database-reference-sql-functions-string-strip-accents#what-it-does); the last line of this block replaces them with [translate](/develop/docs/dev-database-reference-sql-functions-string-translate). - **Case is kept.** `strip_accents('Crème')` is `'Creme'`, so it doesn't equal `'creme'`. Combine it with [lower](/develop/docs/dev-database-reference-sql-functions-string-lower) to ignore case as well. ``` run("SELECT strip_accents(123)") run("SELECT strip_accents('\\xAA'::BLOB)") run("SELECT strip_accents('Cr\u00e8me') = 'creme', lower(strip_accents('Cr\u00e8me')) = 'creme'") run("SELECT translate(strip_accents('\u0141\u00f3d\u017a'), '\u0141\u0142\u00f8', 'Llo')") ``` ``` InternalError: Binder Error: No function matches the given name and argument types 'strip_accents(INTEGER_LITERAL)'. You might need to add explicit type casts. InternalError: Binder Error: No function matches the given name and argument types 'strip_accents(BLOB)'. You might need to add explicit type casts. [(False, True)] [('Lodz',)] ``` ## Similar functions | Function | What it does with `'Crème'` | Result | | --- | --- | --- | | `strip_accents` | removes the accent | `'Creme'` | | [nfc_normalize](/develop/docs/dev-database-reference-sql-functions-string-nfc-normalize) | keeps the accent, and composes a decomposed `è` into one code point | `nfc_normalize('Cre\u0300me') = 'Crème'` is `true` | | [COLLATE noaccent](/develop/docs/dev-database-reference-sql-functions-string-collate) | compares without regard to accents, but with regard to case | `'Crème' COLLATE noaccent = 'creme'` is `false` | | [COLLATE nocase.noaccent](/develop/docs/dev-database-reference-sql-functions-string-collate) | compares without regard to accents or case | `'É' COLLATE nocase.noaccent = 'e'` is `true` | | [lower](/develop/docs/dev-database-reference-sql-functions-string-lower) | changes case and keeps accents | (see its page) | ``` run("SELECT strip_accents('Cr\u00e8me'), nfc_normalize('Cre\u0300me') = 'Cr\u00e8me', " "'Cr\u00e8me' COLLATE noaccent = 'creme'") run("SELECT '\u00c9' COLLATE nocase.noaccent = 'e'") ``` ``` [('Creme', True, False)] [(True,)] ``` Clean up: ``` run(f"DROP TABLE IF EXISTS {TABLE}") run(f"DROP SCHEMA IF EXISTS {SCHEMA}") conn.close() ``` ``` [] [] ``` ## See also - [Text basics](/develop/docs/dev-database-reference-sql-functions-string-text-basics): all the text functions. - [Where filters run](/develop/docs/dev-database-reference-sql-select#where-filters-run) and [pushdowns](/develop/docs/dev-database-reference-pushdowns). - [EXPLAIN](/develop/docs/dev-database-reference-sql-explain): how to read a plan. - [nfc_normalize](/develop/docs/dev-database-reference-sql-functions-string-nfc-normalize), [COLLATE nocase and noaccent](/develop/docs/dev-database-reference-sql-functions-string-collate) and [lower](/develop/docs/dev-database-reference-sql-functions-string-lower).