ClickHouse SQL

Support for ClickHouse SQL that reads your queries the way ClickHouse's own parser does.

Features

Highlighting. Words are coloured by how the parser reads them, so a column called timestamp or key looks like a name, not a keyword.
Syntax errors as you type, in ClickHouse's words, such as Expected one of: BY, end of query.
Formatting. Format Document and Format Selection lay out queries like clickhouse format, changing only whitespace and the case of keywords.
Autocomplete of the keywords that fit at the cursor and of ClickHouse's functions, types, settings, table engines and formats.
Engine arguments. In ENGINE = Name(...), autocomplete offers what the argument at the cursor takes, such as a ZooKeeper path, a column of the table of a type that fits, a format or a cluster, and signature help shows the engine's parameters.
Outline and breadcrumbs list each statement, such as CREATE TABLE db.t or SELECT … FROM db.t, with its CTEs and the columns it defines.
Folding of statements, subqueries and comments of several lines, and of -- #region ... -- #endregion blocks.
Expand Selection grows from the word at the cursor to its expression, call, clause, subquery and statement, and Shrink Selection goes back.
Hover and signature help show ClickHouse's documentation of functions, settings, engines and formats, and the arguments of the function you are typing.
Go to definition, references and rename of aliases, CTEs, table aliases and lambda and query parameters, scoped as ClickHouse scopes them; a name that ClickHouse could read otherwise is left alone.
Server check (off by default). Your ClickHouse server checks the names, functions and types in each SELECT, and autocomplete offers its databases, tables and columns.

Install

Search for ClickHouse SQL in the Extensions view and select Install, or run code --install-extension valerypetrov.clickhouse-sql. It needs VS Code 1.90 or newer.

Files ending in .chsql or .clickhouse.sql open as ClickHouse SQL. For other files, add a files.associations entry such as "*.sql": "clickhouse-sql", or pick ClickHouse SQL with Change Language Mode.

Settings

Setting	Default	What it does
`clickhouseSql.format.keywordCase`	`upper`	The case of keywords when formatting: `upper`, `lower` or `preserve`.
`clickhouseSql.maxFileSize`	`5000000`	Longer files, in characters, get none of the features; a user setting only.
`clickhouseSql.server.enabled`	`false`	Turns the server check on.
`clickhouseSql.server.url`	`http://localhost:8123`	The HTTP interface of the server.
`clickhouseSql.server.user`	`default`	The ClickHouse user. Set its password with ClickHouse SQL: Set Server Password.
`clickhouseSql.server.database`	empty	The database of table names without one; empty means the user's default.
`clickhouseSql.server.timeoutMs`	`5000`	How long to wait for the server, in milliseconds.

The clickhouseSql.server settings count only in your user settings, never in a workspace's.

ClickHouse SQL: Refresh Schema reads the server's databases, tables and columns again.

The server check sends only EXPLAIN QUERY TREE of your SELECTs and reads of system.databases, system.tables and system.columns, always with readonly=1; the password stays in VS Code's secret storage.

License

Apache License 2.0 with the Commons Clause: free to use, modify and share, but not to sell. See NOTICE.