fix: bigint 0n short-circuit in SQL AND + NaN-safe sort comparator

- evaluator.ts AND: `left === 0` didn't catch bigint zero (0n) — FALSE AND
  NULL should return FALSE per SQL three-valued logic, but returned NULL
  when the FALSE value was 0n
- executor.ts multi-column ORDER BY: `av - bv` returns NaN when either
  operand is NaN, causing undefined sort behavior — now uses < > operators
- docs: pg-wire SQLSTATE error code table, error-handling cross-reference

Author: teamchong

docs/src/content/docs/error-handling.mdx

@@ -86,6 +86,10 @@ The response body always includes `{ error: string }` and, for `QueryModeError`,
 { "error": "Column not found in events: foo", "code": "SCHEMA_MISMATCH" }
 ```
 
+## PostgreSQL SQLSTATE codes
+
+When connecting via the [pg-wire protocol](/querymode/pg-wire/), errors include standard SQLSTATE codes (e.g., `42P01` for table not found, `57014` for timeout). See [pg-wire error codes](/querymode/pg-wire/#error-codes) for the full mapping.
+
 ## DataFrame validation errors
 
 The DataFrame API validates arguments eagerly and throws `QueryModeError` with `QUERY_FAILED`:

docs/src/content/docs/pg-wire.mdx

@@ -82,7 +82,23 @@ The handler manages the full connection lifecycle:
 1. **Startup** — SSL negotiation (rejected), authentication (always ok), server parameters
 2. **Query** — SQL parsing, compilation, execution via the QueryMode pipeline
 3. **Response** — `RowDescription` + `DataRow` messages with proper type OIDs
-4. **Error** — SQL errors return `ErrorResponse` and the connection stays open
+4. **Error** — SQL errors return `ErrorResponse` with proper SQLSTATE codes and the connection stays open
+
+## Error codes
+
+Errors include standard PostgreSQL SQLSTATE codes so BI tools can classify them:
+
+| QueryMode error | SQLSTATE | Meaning |
+|----------------|----------|---------|
+| `TABLE_NOT_FOUND` | `42P01` | Undefined table |
+| `COLUMN_NOT_FOUND` | `42703` | Undefined column |
+| `INVALID_FILTER`, `INVALID_AGGREGATE` | `42601` | Syntax error |
+| `SCHEMA_MISMATCH` | `42804` | Datatype mismatch |
+| `INVALID_FORMAT` | `08P01` | Protocol violation |
+| `QUERY_TIMEOUT`, `NETWORK_TIMEOUT` | `57014` | Query canceled |
+| `MEMORY_EXCEEDED` | `53200` | Out of memory |
+| `QUERY_FAILED` | `XX000` | Internal error |
+| Other | `42000` | Generic syntax error (default) |
 
 ## Type mapping
 

src/sql/evaluator.ts

@@ -90,8 +90,8 @@ function evaluateBinary(op: string, leftExpr: SqlExpr, rightExpr: SqlExpr, row:
   if (op === "and") {
     const left = evaluateExpr(leftExpr, row);
     const right = evaluateExpr(rightExpr, row);
-    if (left === false || left === 0) return false;
-    if (right === false || right === 0) return false;
+    if (left === false || left === 0 || left === 0n) return false;
+    if (right === false || right === 0 || right === 0n) return false;
     if (left === null || right === null) return null;
     return isTruthy(left) && isTruthy(right);
   }

src/sql/executor.ts

@@ -125,7 +125,7 @@ export class SqlWrappingExecutor implements QueryExecutor {
           if (av === null || av === undefined) return 1;
           if (bv === null || bv === undefined) return -1;
           let cmp: number;
-          if (typeof av === "number" && typeof bv === "number") cmp = av - bv;
+          if (typeof av === "number" && typeof bv === "number") cmp = av < bv ? -1 : av > bv ? 1 : 0;
           else if (typeof av === "bigint" && typeof bv === "bigint") cmp = av < bv ? -1 : av > bv ? 1 : 0;
           else if (typeof av === "bigint" && typeof bv === "number") { if (!Number.isFinite(bv)) { cmp = bv === Infinity ? -1 : 1; } else { const bb = BigInt(Math.trunc(bv)); cmp = av < bb ? -1 : av > bb ? 1 : 0; } }
           else if (typeof av === "number" && typeof bv === "bigint") { if (!Number.isFinite(av)) { cmp = av === Infinity ? 1 : -1; } else { const ab = BigInt(Math.trunc(av)); cmp = ab < bv ? -1 : ab > bv ? 1 : 0; } }