doc: separate in-types and out-types in SQLite conversion docs · nodejs/node@4e54c10

### Type conversion between JavaScript and SQLite

When Node.js writes to or reads from SQLite it is necessary to convert between

When Node.js writes to or reads from SQLite, it is necessary to convert between

JavaScript data types and SQLite's [data types][]. Because JavaScript supports

more data types than SQLite, only a subset of JavaScript types are supported.

Attempting to write an unsupported data type to SQLite will result in an

exception.

| SQLite | JavaScript |

| --------- | -------------------------- |

| `NULL` | {null} |

| `INTEGER` | {number} or {bigint} |

| `REAL` | {number} |

| `TEXT` | {string} |

| `BLOB` | {TypedArray} or {DataView} |

| Storage class | JavaScript to SQLite | SQLite to JavaScript |

| ------------- | -------------------------- | ------------------------------------- |

| `NULL` | {null} | {null} |

| `INTEGER` | {number} or {bigint} | {number} or {bigint} _(configurable)_ |

| `REAL` | {number} | {number} |

| `TEXT` | {string} | {string} |

| `BLOB` | {TypedArray} or {DataView} | {Uint8Array} |

APIs that read values from SQLite have a configuration option that determines

whether `INTEGER` values are converted to `number` or `bigint` in JavaScript,

such as the `readBigInts` option for statements and the `useBigIntArguments`

option for user-defined functions. If Node.js reads an `INTEGER` value from

SQLite that is outside the JavaScript [safe integer][] range, and the option to

read BigInts is not enabled, then an `ERR_OUT_OF_RANGE` error will be thrown.

## `sqlite.backup(sourceDb, path[, options])`

[in memory]: https://www.sqlite.org/inmemorydb.html

[parameters are bound]: https://www.sqlite.org/c3ref/bind_blob.html

[prepared statement]: https://www.sqlite.org/c3ref/stmt.html

[safe integer]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isSafeInteger