예제 #1
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def json_array(on_null: JsonOnNull = JsonOnNull.ABSENT, *args) -> Expression:
    """
    Builds a JSON array string from a list of values.

    This function returns a JSON string. The values can be arbitrary expressions. The `on_null`
    behavior defines how to treat `NULL` values.

    Elements which are created from another JSON construction function call (`json_object`,
    `json_array`) are inserted directly rather than as a string. This allows building nested JSON
    structures.

    Examples:
    ::

        >>> json_array() # '[]'
        >>> json_array(JsonOnNull.NULL, 1, "2") # '[1,"2"]'

        >>> # Expressions as values
        >>> json_array(JsonOnNull.NULL, col("orderId"))

        >>> json_array(JsonOnNull.NULL, null_of(DataTypes.STRING()))   # '[null]'
        >>> json_array(JsonOnNull.ABSENT, null_of(DataTypes.STRING())) # '[]'

        >>> json_array(JsonOnNull.NULL, json_array(JsonOnNull.NULL, 1)) # '[[1]]'

    .. seealso:: :func:`~pyflink.table.expressions.json_object`
    """
    return _varargs_op("jsonArray", *(on_null._to_j_json_on_null(), *args))
예제 #2
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def json_object(on_null: JsonOnNull = JsonOnNull.NULL, *args) -> Expression:
    """
    Builds a JSON object string from a list of key-value pairs.

    `args` is an even-numbered list of alternating key/value pairs. Note that keys must be
    non-`NULL` string literals, while values may be arbitrary expressions.

    This function returns a JSON string. The `on_null` behavior defines how to treat `NULL` values.

    Values which are created from another JSON construction function call (`json_object`,
    `json_array`) are inserted directly rather than as a string. This allows building nested JSON
    structures.

    Examples:
    ::

        >>> json_object() # '{}'
        >>> json_object(JsonOnNull.NULL, "K1", "V1", "K2", "V2") # '{"K1":"V1","K2":"V2"}'

        >>> # Expressions as values
        >>> json_object(JsonOnNull.NULL, "orderNo", col("orderId"))

        >>> json_object(JsonOnNull.NULL, "K1", null_of(DataTypes.STRING()))   # '{"K1":null}'
        >>> json_object(JsonOnNull.ABSENT, "K1", null_of(DataTypes.STRING())) # '{}'

        >>> # '{"K1":{"K2":"V"}}'
        >>> json_object(JsonOnNull.NULL, "K1", json_object(JsonOnNull.NULL, "K2", "V"))

    .. seealso:: :func:`~pyflink.table.expressions.json_array`
    """
    return _varargs_op("jsonObject", *(on_null._to_j_json_on_null(), *args))
예제 #3
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def json_object(on_null: JsonOnNull = JsonOnNull.NULL, *args) -> Expression:
    """
    Builds a JSON object string from a list of key-value pairs.

    `args` is an even-numbered list of alternating key/value pairs. Note that keys must be
    non-`NULL` string literals, while values may be arbitrary expressions.

    This function returns a JSON string. The `on_null` behavior defines how to treat `NULL` values.

    Examples:
    ::

        >>> json_object() # '{}'
        >>> json_object(JsonOnNull.NULL, "K1", "V1", "K2", "V2") # '{"K1":"V1","K2":"V2"}'

        >>> # Expressions as values
        >>> json_object(JsonOnNull.NULL, "orderNo", col("orderId"))

        >>> json_object(JsonOnNull.NULL, "K1", null_of(DataTypes.STRING()))   # '{"K1":null}'
        >>> json_object(JsonOnNull.ABSENT, "K1", null_of(DataTypes.STRING())) # '{}'

        >>> # '{"K1":{"K2":"V"}}'
        >>> json_object(JsonOnNull.NULL, "K1", json_object(JsonOnNull.NULL, "K2", "V"))
    """
    return _varargs_op("jsonObject", *(on_null._to_j_json_on_null(), *args))
예제 #4
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def json_array_agg(on_null: JsonOnNull, item_expr) -> Expression:
    """
    Builds a JSON object string by aggregating items into an array.

    Item expressions can be arbitrary, including other JSON functions. If a value is `NULL`, the
    `on_null` behavior defines what to do.

    This function is currently not supported in `OVER` windows, unbounded session windows, or hop
    windows.

    Examples:
    ::

        >>> # '["Apple","Banana","Orange"]'
        >>> orders.select(json_array_agg(JsonOnNull.NULL, col("product")))
    """
    return _binary_op("jsonArrayAgg", on_null._to_j_json_on_null(), item_expr)
예제 #5
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def json_object_agg(on_null: JsonOnNull, key_expr: Union[str, Expression[str]],
                    value_expr) -> Expression:
    """
    Builds a JSON object string by aggregating key-value expressions into a single JSON object.

    The key expression must return a non-nullable character string. Value expressions can be
    arbitrary, including other JSON functions. If a value is `NULL`, the `on_null` behavior defines
    what to do.

    Note that keys must be unique. If a key occurs multiple times, an error will be thrown.

    This function is currently not supported in `OVER` windows.

    Examples:
    ::

        >>> # '{"Apple":2,"Banana":17,"Orange":0}'
        >>> orders.select(json_object_agg(JsonOnNull.NULL, col("product"), col("cnt")))
    """
    return _ternary_op("jsonObjectAgg", on_null._to_j_json_on_null(), key_expr,
                       value_expr)