SQL Formatter
SQL Formatter is a JavaScript library for pretty-printing SQL queries.
It started as a port of a PHP Library, but has since considerably diverged.
It supports various SQL dialects: GCP BigQuery, IBM DB2, Apache Hive, MariaDB, MySQL, Couchbase N1QL, Oracle PL/SQL, PostgreSQL, Amazon Redshift, SingleStoreDB, Snowflake, Spark, SQL Server Transact-SQL, Trino/Presto. See language option docs for more details.
It does not support:
- Stored procedures.
- Changing of the delimiter type to something else than
;
.
โ Try the demo.
Install
Get the latest version from NPM:
npm install sql-formatter
Also available with yarn:
yarn add sql-formatter
Usage
Usage as library
import { format } from 'sql-formatter';
console.log(format('SELECT * FROM tbl', { language: 'mysql' }));
This will output:
SELECT
*
FROM
tbl
You can also pass in configuration options:
format('SELECT * FROM tbl', {
language: 'spark',
tabWidth: 2,
keywordCase: 'upper',
linesBetweenQueries: 2,
});
Placeholders replacement
In addition to formatting, this library can also perform placeholder replacement in prepared SQL statements:
format('SELECT * FROM tbl WHERE foo = ?', {
params: ["'bar'"],
});
Results in:
SELECT
*
FROM
tbl
WHERE
foo = 'bar'
For more details see docs of params option.
Usage from command line
The CLI tool will be installed under sql-formatter
and may be invoked via npx sql-formatter
:
sql-formatter -h
usage: sql-formatter [-h] [-o OUTPUT] \
[-l {bigquery,db2,hive,mariadb,mysql,n1ql,plsql,postgresql,redshift,singlestoredb,snowflake,spark,sql,sqlite,transactsql,trino,tsql}] [-c CONFIG] [--version] [FILE]
SQL Formatter
positional arguments:
FILE Input SQL file (defaults to stdin)
optional arguments:
-h, --help show this help message and exit
-o, --output OUTPUT
File to write SQL output (defaults to stdout)
--fix Update the file in-place
-l, --language {bigquery,db2,hive,mariadb,mysql,n1ql,plsql,postgresql,redshift,singlestoredb,snowflake,spark,sql,sqlite,trino,tsql}
SQL dialect (defaults to basic sql)
-c, --config CONFIG
Path to config json file (will use default configs if unspecified)
--version show program's version number and exit
By default, the tool takes queries from stdin and processes them to stdout but
one can also name an input file name or use the --output
option.
echo 'select * from tbl where id = 3' | sql-formatter
select
*
from
tbl
where
id = 3
The tool also accepts a JSON config file with the --config
option that takes this form:
{
"language": "spark",
"tabWidth": 2,
"keywordCase": "upper",
"linesBetweenQueries": 2
}
All fields are optional and all fields that are not specified will be filled with their default values.
Configuration options
language
the SQL dialect to use (when usingformat()
).dialect
the SQL dialect to use (when usingformatDialect()
since version 12).tabWidth
amount of indentation to use.useTabs
to use tabs for indentation.keywordCase
uppercases or lowercases keywords.indentStyle
defines overall indentation style.logicalOperatorNewline
newline before or after boolean operator (AND, OR, XOR).tabulateAlias
aligns column aliases vertically (deprecated!).commaPosition
where to place the comma in column lists (deprecated!).expressionWidth
maximum number of characters in parenthesized expressions to be kept on single line.linesBetweenQueries
how many newlines to insert between queries.denseOperators
packs operators densely without spaces.newlineBeforeSemicolon
places semicolon on separate line.params
collection of values for placeholder replacement.paramTypes
specifies parameter placeholders types to support.
Usage without NPM
If you don't use a module bundler, clone the repository, run npm install
and grab a file from /dist
directory to use inside a <script>
tag.
This makes SQL Formatter available as a global variable window.sqlFormatter
.
Usage in editors
Frequently Asked Questions
Parse error: Unexpected ... at line ...
The most common cause is that you haven't specified an SQL dialect. Instead of calling the library simply:
format('select [col] from tbl');
// Throws: Parse error: Unexpected "[col] from" at line 1 column 8
pick the proper dialect, like:
format('select [col] from tbl', { language: 'transactsql' });
Or when using the VSCode extension: Settings -> Prettier-SQL: SQLFlavourOverride.
Module parse failed: Unexpected token
This typically happens when bundling an appication with Webpack.
The cause is that Babel (through babel-loader
) is not configured
to support class properties syntax:
| export default class ExpressionFormatter {
> inline = false;
This syntax is widely supported in all major browsers (except old IE)
and support for it is included to the default @babel/preset-env
.
Possible fixes:
- Update to newer Babel / Webpack
- Switch to
@babel/preset-env
- Include plugin
@babel/plugin-proposal-class-properties
The future
The development of this formatter is currently in maintenance mode. Bugs will get fixed if feasible, but new features will likely not be added.
I have started a new SQL formatting tool: prettier-plugin-sql-cst.
- It solves several problems which can't be fixed in SQL Formatter because of fundamental problems in its arhictecture.
- It makes use of the Prettier layout algorithm, doing a better job of splitting long expressions to multiple lines.
- It takes much more opinionated approach to SQL formatting, giving only a very limited set of options to adjust the code style.
- It already has full support for SQLite and BigQuery syntax. It should work for the most common SQL code in various other dialects.
Give it a try if you'd like to take your SQL auto-formatting to the next level.
Contributing
Please see CONTRIBUTING.md