A ClickHouse SQL parser written in Go. Parses ClickHouse SQL syntax into an Abstract Syntax Tree (AST) and generates EXPLAIN output matching ClickHouse's format.
go get github.com/sqlc-dev/doubleclick
package main import ( "context" "encoding/json" "fmt" "strings" "github.com/sqlc-dev/doubleclick/parser" ) func main() { sql := `SELECT id, name FROM users WHERE active = 1 ORDER BY created_at DESC LIMIT 10` stmts, err := parser.Parse(context.Background(), strings.NewReader(sql)) if err != nil { panic(err) } // Serialize to JSON jsonBytes, _ := json.MarshalIndent(stmts[0], "", " ") fmt.Println(string(jsonBytes)) // Or print EXPLAIN AST output (matches ClickHouse format) fmt.Println(parser.Explain(stmts[0])) }
JSON output:
{
"selects": [
{
"columns": [
{ "parts": ["id"] },
{ "parts": ["name"] }
],
"from": {
"tables": [
{ "table": { "table": { "table": "users" } } }
]
},
"where": {
"left": { "parts": ["active"] },
"op": "=",
"right": { "type": "Integer", "value": 1 }
},
"order_by": [
{
"expression": { "parts": ["created_at"] },
"descending": true
}
],
"limit": { "type": "Integer", "value": 10 }
}
]
}EXPLAIN output:
SelectWithUnionQuery (children 1)
ExpressionList (children 1)
SelectQuery (children 4)
ExpressionList (children 2)
Identifier id
Identifier name
TablesInSelectQuery (children 1)
TablesInSelectQueryElement (children 1)
TableExpression (children 1)
TableIdentifier (children 1)
Identifier users
Function equals (children 1)
ExpressionList (children 2)
Identifier active
Literal UInt64_1
ExpressionList (children 1)
OrderByElement (children 1)
Identifier created_at
Literal UInt64_10
- Parses SELECT, INSERT, CREATE, DROP, ALTER, and other ClickHouse statements
- Handles ClickHouse-specific syntax (Array types, PREWHERE, SAMPLE, etc.)
- Supports JOINs, subqueries, CTEs, window functions, and complex expressions
- Generates JSON-serializable AST nodes
- Produces EXPLAIN AST output matching ClickHouse's format