# Troubleshooting
## Both drivers
### `SQLSTATE[HY000]: General error: 25 column index out of range`
More bindings were collected than the query has `?` placeholders. Almost always a **quoted placeholder**:
```php
//wrong: renders the literal text `"?"`, but still binds the value
$handler->statement('SELECT * FROM t WHERE name = "{name}"', ['name' => 'marc']);
//right
$handler->statement('SELECT * FROM t WHERE name = {name}', ['name' => 'marc']);
```
To see what a render really produced:
```php
$binds = new MMO\pdo\statements\Binds();
$sql = $stmt->render(['binds' => $binds]);
var_dump($sql, $binds->toArray()); //the `?` count must equal the bind count
```
### `unrecognized token: "{"`
A placeholder was not recognised and stayed in the query as literal text. A placeholder's name **must start
with a letter**: `{_where}` is not a placeholder at all.
### `eNotFound: cannot filter … no such column`
The query filters on a name that is neither a column of the table nor a property of its entity (a property
without a column holds its default on every row, and is decided without SQL: see
[Repository](Repository.md#filters)).
Give the table the column, or filter on ones it has. Unlike the field list, a filter is never silently
dropped — that would return more rows than were asked for.
### Nothing was written, and no error
Historically: `do()` opened a transaction that was never committed, and `disconnect()` rolled it back. Fixed —
but if you see it again, check `inTransaction()` after your write and make sure nothing calls
`startTransaction()` without a matching `commit()`.
## SQLite
### `unable to open database file`
Permissions: SQLite needs write access to the **directory**, not just the file, because it creates a journal
beside it. Under a web server that means writable by the server user, not by you.
For a demo or a test, avoid it entirely with `SqliteHandler::MEMORY`.
### `database is locked`
Another connection holds a write transaction. Look for a `do()` whose exception was swallowed, or a handler
that was never disconnected.
### `ON CONFLICT clause does not match any PRIMARY KEY or UNIQUE constraint`
An upsert's conflict target must match **one** unique index exactly — `ON CONFLICT(id,name)` is invalid when
`id` and `name` are separate keys. `Table::store()` picks a valid target itself; if you called
`insertStatement()->duplicate()` by hand, mark only the columns of a single key as `true`.
### The id of a deleted row is given to the next one
A table mmo.pdo created before 2026-09 has no `AUTOINCREMENT`, even when its key declared one: its id is SQLite's
rowid, which gives the id of the highest row deleted again (`SELECT sql FROM sqlite_master WHERE name = 'user'`
shows `PRIMARY KEY(id)`). SQLite cannot add the keyword to a table: rebuild it, with its other columns and
constraints.
```sql
BEGIN;
CREATE TABLE `user_new` (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL);
INSERT INTO `user_new` SELECT * FROM `user`;
DROP TABLE `user`;
ALTER TABLE `user_new` RENAME TO `user`;
COMMIT;
```
Its sequence starts at the highest id copied: an id deleted before the rebuild, above that one, can still come
back once. A key the repository generates itself (`INT PRIMARY KEY`) is another case: see
[Repository](Repository.md#ids).
## MySQL
### `Access denied for user 'root'@'localhost' (using password: YES)`
```bash
sudo mysql -e "ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'mypassword'"
```
Or from a client:
```sql
FLUSH PRIVILEGES;
ALTER USER 'root'@'localhost' IDENTIFIED BY 'YOURNEWPASSWORD';
FLUSH PRIVILEGES;
```
### The password is rejected as too weak
See what the server requires:
```sql
SHOW VARIABLES LIKE 'validate_password%';
```
```
+--------------------------------------+-------+
| Variable_name | Value |
+--------------------------------------+-------+
| validate_password.check_user_name | ON |
| validate_password.dictionary_file | |
| validate_password.length | 6 |
| validate_password.mixed_case_count | 1 |
| validate_password.number_count | 1 |
| validate_password.policy | LOW |
| validate_password.special_char_count | 1 |
+--------------------------------------+-------+
```
Check a candidate:
```sql
SELECT VALIDATE_PASSWORD_STRENGTH('weak'); -- 25
SELECT VALIDATE_PASSWORD_STRENGTH('lessweak$_@123'); -- 50
SELECT VALIDATE_PASSWORD_STRENGTH('N0Tweak$_@123!'); -- 100
```
Or relax the policy:
```sql
SET GLOBAL validate_password.length = 6;
SET GLOBAL validate_password.number_count = 0;
```