# Builder State

This page explains where the query builder keeps its state and what that means for how you call it.

## State Lives in Static Fields

`MySQLPool` has no instances: `table()`, `where()`, and the other builder methods modify static fields on the class and return the class itself (`typeof MySQLPool`) for chaining (`src/MySQLPool.ts:20-30`).

| Field | Written by |
|---|---|
| `tableName`, `currentTarget` | `table()` |
| `selectAry` | `select()` |
| `joinAry` | `innerJoin()`, `leftJoin()`, `rightJoin()` |
| `whereAry`, `bindingAry` | `where()` |
| `orderAry` | `orderBy()` |
| `queryLimit`, `queryOffset` | `limit()`, `offset()` |
| `withTotal` | `total()` |
| `setAry` | `increase()`, `update()` |

## Every Chain Starts with `table()`

Only `table()` calls `reset()` to clear these fields (`src/MySQLPool.ts:117-137`). Running `get()`, `update()`, or another execution method does **not** clear them, so:

```typescript
await MySQLPool.table("users").where("id", 1).get();

// Wrong: reuses the previous table name and WHERE, so it queries id = 1 again
await MySQLPool.where("status", "active").get();

// Right
await MySQLPool.table("users").where("status", "active").get();
```

`currentTarget` persists too: calling `query(sql)` without a `target` after `table("x", "write")` uses the write pool.

## Related Pages

- [API Reference](/api-reference)