fix: implement Connector interface methods in ClickHouse driver

Replace getSchema() (not in interface) with the required listSchemas(),
listTables(), and describeTable() methods to match the Connector contract.

Author: aidtya

packages/drivers/src/clickhouse.ts

@@ -90,24 +90,39 @@ export async function connect(config: ConnectionConfig): Promise<Connector> {
       }
     },
 
-    async getSchema(database_?: string): Promise<SchemaColumn[]> {
-      const db = database_ ?? database
+    async listSchemas(): Promise<string[]> {
+      const { rows } = await httpQuery("SHOW DATABASES")
+      return rows.map((r) => String(r[0]))
+    },
+
+    async listTables(schema: string): Promise<Array<{ name: string; type: string }>> {
+      const { rows } = await httpQuery(`
+        SELECT name, engine
+        FROM system.tables
+        WHERE database = '${schema}'
+        ORDER BY name
+      `)
+      return rows.map((r) => ({
+        name: String(r[0]),
+        type: String(r[1]).toLowerCase().includes("view") ? "view" : "table",
+      }))
+    },
+
+    async describeTable(schema: string, table: string): Promise<SchemaColumn[]> {
       const { rows } = await httpQuery(`
         SELECT
-          table_name,
           column_name,
           data_type,
           is_nullable
         FROM information_schema.columns
-        WHERE table_schema = '${db}'
-        ORDER BY table_name, ordinal_position
+        WHERE table_schema = '${schema}'
+          AND table_name = '${table}'
+        ORDER BY ordinal_position
       `)
-
       return rows.map((row) => ({
-        table_name: String(row[0]),
-        name: String(row[1]),
-        data_type: String(row[2]),
-        nullable: row[3] === "YES" || row[3] === "1",
+        name: String(row[0]),
+        data_type: String(row[1]),
+        nullable: row[2] === "YES" || row[2] === "1",
       }))
     },