# json_strings_each_row

## Description

One named JSON object per row with every field encoded as a JSON string.
SQL NULL is the string `"ᴺᵁᴸᴸ"`; collections use their complete native text
inside the string. Known input fields must be strings; bare JSON null is rejected.
Nullable targets also accept the string `"NULL"`, ignoring ASCII case.
Input converts the complete field text through the declared column type.

Input and output. Select it with `FORMAT json_strings_each_row`. Names ignore ASCII case; use the snake_case name shown here.

Objects retain named fields, but every value is a JSON string containing complete native text. Numeric digits do not pass through a JSON numeric representation, and collections remain text inside their field string.

SQL NULL uses the quoted marker shown above. Input known fields must be strings; their complete text is converted through each destination declaration. Use json_each_row when the consumer needs ordinary JSON value types.

```text
SELECT expressions FORMAT json_strings_each_row;
INSERT INTO table [(columns)] [SETTINGS ...] FORMAT json_strings_each_row
<data>
```

## Example usage

```sql
SELECT CAST(7 AS Int64) AS id, 'Ada' AS name FORMAT json_strings_each_row;
```

```text
{"id":"7","name":"Ada"}
```

```sql
SELECT NULL AS value FORMAT json_strings_each_row;
```

```text
{"value":"ᴺᵁᴸᴸ"}
```

## Format settings

Use a statement `SETTINGS` clause; these options are not persisted by `SET`.

| Setting                              | Type     | Default | Meaning                                                                                                                    |
| ------------------------------------ | -------- | ------- | -------------------------------------------------------------------------------------------------------------------------- |
| `ignore_unknown_fields`              | `Bool`   | `0`     | Skip input keys and header names that match no target column instead of failing.                                           |
| `json_array_of_rows`                 | `Bool`   | `0`     | Wrap all output rows in one JSON array.                                                                                    |
| `json_empty_as_default`              | `Bool`   | `0`     | Give empty JSON string fields their SQL or native type default.                                                            |
| `json_escape_slashes`                | `Bool`   | `1`     | Escape unescaped forward slashes in JSON output strings.                                                                   |
| `json_strict_escapes`                | `Bool`   | `1`     | Reject invalid JSON escapes; otherwise preserve their literal backslash spelling.                                          |
| `json_strings_each_row_sql_defaults` | `Bool`   | `1`     | Evaluate SQL DEFAULT expressions for omitted or defaulted whole-text JSON fields; off supplies their native type defaults. |
| `json_validate_utf8`                 | `Bool`   | `0`     | Replace invalid UTF-8 sequences in whole-text JSON output with replacement characters; off preserves byte-string payloads. |
| `snappy_mode`                        | `String` | `basic` | Read Snappy client files as basic (Hadoop blocks) or framed (standard streaming format).                                   |