westonpace commented on a change in pull request #11982:
URL: https://github.com/apache/arrow/pull/11982#discussion_r809469564
##########
File path: format/FlightSql.proto
##########
@@ -867,6 +867,167 @@ enum SqlSupportsConvert {
SQL_CONVERT_VARCHAR = 19;
}
+enum SqlDataType {
+ SQL_TYPE_UNKNOWN_TYPE = 0;
+ SQL_TYPE_CHAR = 1;
+ SQL_TYPE_NUMERIC = 2;
+ SQL_TYPE_DECIMAL = 3;
+ SQL_TYPE_INTEGER = 4;
+ SQL_TYPE_SMALLINT = 5;
+ SQL_TYPE_FLOAT = 6;
+ SQL_TYPE_REAL = 7;
+ SQL_TYPE_DOUBLE = 8;
+ SQL_TYPE_DATETIME = 9;
+ SQL_TYPE_INTERVAL = 10;
+ SQL_TYPE_VARCHAR = 12;
+}
+
+enum SqlDatetimeSubcode {
+ option allow_alias = true;
+ SQL_SUBCODE_UNKNOWN = 0;
+ SQL_SUBCODE_YEAR = 1;
+ SQL_SUBCODE_DATE = 1;
+ SQL_SUBCODE_TIME = 2;
+ SQL_SUBCODE_MONTH = 2;
+ SQL_SUBCODE_TIMESTAMP = 3;
+ SQL_SUBCODE_DAY = 3;
+ SQL_SUBCODE_TIME_WITH_TIMEZONE = 4;
+ SQL_SUBCODE_HOUR = 4;
+ SQL_SUBCODE_TIMESTAMP_WITH_TIMEZONE = 5;
+ SQL_SUBCODE_MINUTE = 5;
+ SQL_SUBCODE_SECOND = 6;
+ SQL_SUBCODE_YEAR_TO_MONTH = 7;
+ SQL_SUBCODE_DAY_TO_HOUR = 8;
+ SQL_SUBCODE_DAY_TO_MINUTE = 9;
+ SQL_SUBCODE_DAY_TO_SECOND = 10;
+ SQL_SUBCODE_HOUR_TO_MINUTE = 11;
+ SQL_SUBCODE_HOUR_TO_SECOND = 12;
+ SQL_SUBCODE_MINUTE_TO_SECOND = 13;
+ SQL_SUBCODE_INTERVAL_YEAR = 101;
+ SQL_SUBCODE_INTERVAL_MONTH = 102;
+ SQL_SUBCODE_INTERVAL_DAY = 103;
+ SQL_SUBCODE_INTERVAL_HOUR = 104;
+ SQL_SUBCODE_INTERVAL_MINUTE = 105;
+ SQL_SUBCODE_INTERVAL_SECOND = 106;
+ SQL_SUBCODE_INTERVAL_YEAR_TO_MONTH = 107;
+ SQL_SUBCODE_INTERVAL_DAY_TO_HOUR = 108;
+ SQL_SUBCODE_INTERVAL_DAY_TO_MINUTE = 109;
+ SQL_SUBCODE_INTERVAL_DAY_TO_SECOND = 110;
+ SQL_SUBCODE_INTERVAL_HOUR_TO_MINUTE = 111;
+ SQL_SUBCODE_INTERVAL_HOUR_TO_SECOND = 112;
+ SQL_SUBCODE_INTERVAL_MINUTE_TO_SECOND = 113;
+}
+
+enum Nullable {
+ /**
+ * Indicates that the fields does not allow the use of null values.
+ */
+ NULLABILITY_NO_NULLS = 0;
+
+ /**
+ * Indicates that the fields allow the use of null values.
+ */
+ NULLABILITY_NULLABLE = 1;
+
+ /**
+ * Indicates that nullability of the fields can not be determined.
+ */
+ NULLABILITY_UNKNOWN = 2;
+}
+
+enum Searchable {
+ /**
+ * Indicates that column can not be used in a WHERE clause.
+ */
+ SEARCHABLE_NONE = 0;
+
+ /**
+ * Indicates that the column can be used in a WHERE clause if it is using a
+ * LIKE predicate.
+ */
+ SEARCHABLE_CHAR = 1;
+
+ /**
+ * Indicates that the column can be used in a WHERE clause using other
predicates
+ * except for LIKE.
+ *
+ * - Allowed operators: comparison, quantified comparison, BETWEEN,
+ * DISTINCT, IN, MATCH, and UNIQUE.
+ */
+ SEARCHABLE_BASIC = 2;
+
+ /**
+ * Indicates that the column can be used in a WHERE clause using any
operator.
+ */
+ SEARCHABLE_FULL = 3;
+}
+
+/*
+ * Represents a request to retrieve information about data type supported on a
Flight SQL enabled backend.
+ * Used in the command member of FlightDescriptor for the following RPC calls:
+ * - GetSchema: return the schema of the query.
+ * - GetFlightInfo: execute the catalog metadata request.
+ *
+ * The returned schema will be:
+ * <
+ * type_name: utf8 not null (The name of the data type, for example:
VARCHAR, INTEGER, etc),
+ * data_type: int not null (The SQL data type),
+ * column_size: int (The maximum size supported by that column.
+ * In case of numeric types, this represents the maximum
precision.
+ * In case of string types, this represents the character
length.
+ * In case of datetime data types, this represents the
length in characters of the string representation.
+ * NULL is returned for data types where column size is
not applicable.),
+ * literal_prefix: utf8 (Character or characters used to prefix a literal,
NULL is returned for
+ * data types where a literal prefix is not
applicable.),
+ * literal_suffix: utf8 (Character or characters used to terminate a literal,
+ * NULL is returned for data types where a literal
suffix is not applicable.),
+ * create_params: list<utf8 not null>
+ * (A list of keywords corresponding to which
parameters can be used when creating
+ * a column for that specific type.
+ * NULL is returned if there are no parameters for the
data type definition.),
+ * nullable: int not null (Shows if the data type accepts a NULL value. The
possible values can be seen in the
+ * Nullable enum.),
+ * case_sensitive: bool not null (Shows if a character data type is
case-sensitive in collations and comparisons),
+ * searchable: int not null (Shows how the data type is used in a WHERE
clause. The possible values can be seen in the
+ * Searchable enum.),
+ * unsigned_attribute: bool (Shows if the data type is unsigned. NULL is
returned if the attribute is
+ * not applicable to the data type or the data
type is not numeric.),
+ * fixed_prec_scale: bool not null (Shows if the data type has predefined
fixed precision and scale.),
Review comment:
There is also a slight difference in semantics when `fixed_prec_scale`
is true. `MONEY` can generally be thought of as a decimal with precision 19
and scale 4 but consider this example on SQL Server 2017...
```
CREATE TABLE sample (mon MONEY, deci DECIMAL(10, 4));
INSERT INTO sample (mon, deci) VALUES (1, 1);
SELECT mon / 100000, deci / 100000 FROM sample;
```
This will return:
| mon / 100000 | deci / 100000 |
| ------------- | ------------- |
| 0 | 0.00001 |
This is because (I believe) a data type with `fixed_prec_scale = false` is
not allowed to be widened as a natural result of arithmetic operations.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
