Add initial ClickHouse support with the following components:
- Parser using sqlc-dev/doubleclick to parse ClickHouse SQL
- Analyzer for database-only mode (requires live database connection)
- Go codegen with ClickHouse type mappings
- Docker and native sqltest support
- End-to-end test case with authors table example
The implementation requires the clickhouse experiment flag
(SQLCEXPERIMENT=clickhouse) and database-only analyzer mode
(analyzer.database: only) since static analysis is not yet supported.
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...ntation
Key fixes:
- Fix 1-indexed offset from doubleclick parser to 0-indexed for sqlc
- Include comment lines in statement extraction for metadata parsing
- Calculate StmtLen correctly by finding semicolon positions
- Replace ? placeholders with NULL for database introspection
- Skip INSERT/UPDATE/DELETE queries when getting column info (no return cols)
- Pass experiment flag through process.go and vet.go
- Remove trailing semicolons before appending LIMIT 0 for introspection
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...puts
This commit fixes two issues:
1. ClickHouse end-to-end tests: Changed from managed-db context to a new
 clickhouse-specific context. The managed-db context only handles
 PostgreSQL, MySQL, and SQLite. ClickHouse tests now only run when
 a ClickHouse database is available.
2. AnalyzerV2 test outputs: The Experiment flag was not being passed to
 parseOpts in process.go and vet.go. This meant the AnalyzerV2 experiment
 was never actually active, even when tests configured SQLCEXPERIMENT.
 Now that the experiment is properly passed, the test expected outputs
 have been regenerated to match actual AnalyzerV2 behavior.
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...ntext
- Update CLAUDE.md with ClickHouse installation instructions using official
 repository (Ubuntu packages have incompatible old version)
- Add ClickHouse test context to endtoend_test.go with schema migration support
- Import clickhouse-go v2 driver and database/sql for test context
- Add test filtering to only run ClickHouse tests under clickhouse context
- Add generated test output files for clickhouse_authors test case
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- Update ClickHouse to use managed-db context instead of separate context
- Fix detectParameters to count ? placeholders in addition to parsing
 {name:Type} style parameters with doubleclick parser
- Add DROP TABLE IF EXISTS before CREATE TABLE in migrations for
 idempotent schema application
- Set ClickHouse database URI in test config for proper connection
- Add pgrep check for MySQL service detection in native tests
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Co-Authored-By: Claude <noreply@anthropic.com>

- Update ClickHouse test queries to use {name:Type} parameter syntax
 instead of ? placeholders for better type inference
- Add regex-based parameter detection for named parameters
- Add replaceParamsWithNull helper to handle named params in DESCRIBE
- Set NotNull: true for parameters to generate non-nullable Go types
- Remove unused AST walking code that was replaced by regex approach
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Replace regex-based parameter detection with AST walking using the
doubleclick parser. This avoids issues with parameters in comments
being incorrectly detected.
For INSERT VALUES clauses (which doubleclick doesn't fully parse),
extract the VALUES content and parse it as a SELECT to properly
detect parameters through AST walking.
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Co-Authored-By: Claude <noreply@anthropic.com>