Handle engine parentheses in Explain output

claude · claude · commit 73350a4126f7 · 2025-12-13T19:21:28.000Z
When an engine has parentheses (like MergeTree()), output it with
children count and empty ExpressionList, matching ClickHouse's format.

Tests improved to 5090 passing (~74.6% of 6824).
diff --git a/internal/explain/statements.go b/internal/explain/statements.go
@@ -48,7 +48,12 @@ func explainCreateQuery(sb *strings.Builder, n *ast.CreateQuery, indent string,
 		}
 		fmt.Fprintf(sb, "%s Storage definition (children %d)\n", indent, storageChildren)
 		if n.Engine != nil {
-			fmt.Fprintf(sb, "%s  Function %s\n", indent, n.Engine.Name)
+			if n.Engine.HasParentheses {
+				fmt.Fprintf(sb, "%s  Function %s (children %d)\n", indent, n.Engine.Name, 1)
+				fmt.Fprintf(sb, "%s   ExpressionList\n", indent)
+			} else {
+				fmt.Fprintf(sb, "%s  Function %s\n", indent, n.Engine.Name)
+			}
 		}
 		if len(n.OrderBy) > 0 {
 			if len(n.OrderBy) == 1 {

Original file line number	Diff line number	Diff line change
`@@ -48,7 +48,12 @@ func explainCreateQuery(sb strings.Builder, n ast.CreateQuery, indent string,`
`48`	`48`	`}`
`49`	`49`	`fmt.Fprintf(sb, "%s Storage definition (children %d)\n", indent, storageChildren)`
`50`	`50`	`if n.Engine != nil {`
`51`		`- fmt.Fprintf(sb, "%s Function %s\n", indent, n.Engine.Name)`
	`51`	`+ if n.Engine.HasParentheses {`
	`52`	`+ fmt.Fprintf(sb, "%s Function %s (children %d)\n", indent, n.Engine.Name, 1)`
	`53`	`+ fmt.Fprintf(sb, "%s ExpressionList\n", indent)`
	`54`	`+ } else {`
	`55`	`+ fmt.Fprintf(sb, "%s Function %s\n", indent, n.Engine.Name)`
	`56`	`+ }`
`52`	`57`	`}`
`53`	`58`	`if len(n.OrderBy) > 0 {`
`54`	`59`	`if len(n.OrderBy) == 1 {`