feat(database): add ClickHouse data sources (#865)

Adds ClickHouse to Data Sources over its HTTP interface (HTTP/HTTPS, SSH tunnels, session settings, server-side cancellation): browse databases, tables and columns, inspect DDL, run queries and EXPLAIN plans, with ClickHouse dialect completion. Table data stays read-only and manual transactions are rejected, since ClickHouse keys are not unique and HTTP has no transactions.

Results are streamed as JSONCompactEachRowWithNamesAndTypes and parsing stops at the row limit, because result_overflow_mode=break still returns a whole block; errors show only the server's "Code: …" message, including failures raised mid-stream.

Fixes #862

Co-authored-by: kkMihai <[email protected]>

src/features/database/sql/complete.ts

@@ -7,7 +7,15 @@
  */
 import type { DbCompletion, DbCompletionColumn, DbCompletionTable, DbDriver } from "@/platform/ipc";
 import type { Analysis, Clause, TableRef } from "./analyze";
-import { DATA_TYPES, functions, isReserved, joinKeywords, predicateKeywords, statementStarters } from "./dialect";
+import {
+  DATA_TYPES,
+  functions,
+  isReserved,
+  joinKeywords,
+  nameMatcher,
+  predicateKeywords,
+  statementStarters,
+} from "./dialect";
 
 export type CandidateKind =
   | "table"
@@ -55,13 +63,16 @@ export function shouldAutoCompleteSql(analysis: Analysis): boolean {
 
 const MAX_ALL_COLUMNS = 3000;
 
-const eq = (a: string | null | undefined, b: string | null | undefined) =>
-  !!a && !!b && a.toLowerCase() === b.toLowerCase();
-
 /** `name`, quoted when the dialect needs it (case, characters, reserved words). */
 export function quoteIdent(name: string, driver: DbDriver): string {
-  const plain = driver === "postgres" ? /^[a-z_][a-z0-9_$]*$/ : /^[A-Za-z_][A-Za-z0-9_$]*$/;
+  const plain =
+    driver === "postgres"
+      ? /^[a-z_][a-z0-9_$]*$/
+      : driver === "clickhouse"
+        ? /^[A-Za-z_][A-Za-z0-9_]*$/
+        : /^[A-Za-z_][A-Za-z0-9_$]*$/;
   if (plain.test(name) && !isReserved(name)) return name;
+  if (driver === "clickhouse") return `"${name.replace(/\\/g, "\\\\").replace(/"/g, '\\"')}"`;
   const q = driver === "mysql" ? "`" : '"';
   return q + name.split(q).join(q + q) + q;
 }
@@ -94,6 +105,7 @@ export interface CompletionInput {
 }
 
 export function sqlCandidates({ model, analysis: a, driver, sourceName }: CompletionInput): SqlCandidate[] {
+  const eq = nameMatcher(driver);
   const ctx = a.context;
   if (ctx.kind === "none") return [];
   const typedLower = /[a-z]/.test(a.prefix.text) && !/[A-Z]/.test(a.prefix.text);
@@ -224,7 +236,7 @@ export function sqlCandidates({ model, analysis: a, driver, sourceName }: Comple
       else {
         if (ctx.ref.viaJoin) {
           out.push(
-            ...conditionCandidates(a, model, ctx.ref, kw).map((c) => ({
+            ...conditionCandidates(a, model, ctx.ref, kw, driver).map((c) => ({
               ...c,
               label: `${kw("ON")} ${c.label}`,
               insert: `${kw("ON")} ${c.insert ?? c.label}`,
@@ -238,7 +250,7 @@ export function sqlCandidates({ model, analysis: a, driver, sourceName }: Comple
     }
 
     case "joinCondition":
-      out.push(...conditionCandidates(a, model, ctx.ref, kw));
+      out.push(...conditionCandidates(a, model, ctx.ref, kw, driver));
       columnContext("on");
       return out;
 
@@ -322,7 +334,7 @@ export function sqlCandidates({ model, analysis: a, driver, sourceName }: Comple
       if (!visible.some((r) => eq(r.name, c.name))) out.push({ label: c.name, kind: "table", tail: "(CTE)", boost: 0 });
     const fnBoost = clause === "select" || clause === "having" ? 15 : 8;
     for (const f of functions(driver)) {
-      const name = lower ? f.name : f.name.toUpperCase();
+      const name = lower || driver === "clickhouse" ? f.name : f.name.toUpperCase();
       out.push({
         label: name,
         kind: "function",
@@ -372,7 +384,7 @@ function clauseKeywords(clause: Clause, driver: DbDriver, a: Analysis): string[]
     case "returning":
       return ["AS"];
     default:
-      return [...pred, ...DATA_TYPES[driver].map((t) => t.toUpperCase())];
+      return [...pred, ...DATA_TYPES[driver].map((t) => (driver === "clickhouse" ? t : t.toUpperCase()))];
   }
 }
 
@@ -390,6 +402,7 @@ function joinCandidates(
   kw: Kw,
 ): SqlCandidate[] {
   if (!model) return [];
+  const eq = nameMatcher(driver);
   const out: SqlCandidate[] = [];
   const q = (n: string) => quoteIdent(n, driver);
   const seen = new Set<string>();
@@ -446,8 +459,15 @@ function joinCandidates(
 }
 
 /** `JOIN t x ON |` → conditions relating `ref` to the other tables in scope. */
-function conditionCandidates(a: Analysis, model: DbCompletion | null, ref: TableRef, kw: Kw): SqlCandidate[] {
+function conditionCandidates(
+  a: Analysis,
+  model: DbCompletion | null,
+  ref: TableRef,
+  kw: Kw,
+  driver: DbDriver,
+): SqlCandidate[] {
   if (!model || ref.kind !== "table") return [];
+  const eq = nameMatcher(driver);
   const out: SqlCandidate[] = [];
   const find = (r: TableRef) =>
     model.tables.find((t) => eq(t.name, r.name) && (r.schema ? eq(t.schema, r.schema) : true));