usql.columns (U-SQL)
Summary
Returns a row for each column in tables and table types in the schemas of the current database context.
| Column name | Data type | Description |
|---|---|---|
| name | string | Column's name (unique within the object to which the column belongs) |
| object_id_guid | Guid | Identifier of the object to which the columns belongs |
| column_id | int | Column's positional id within the object to which the column belongs (unique within the object) |
| type_id_guid | Guid | Column type's identifier. To return the name of the type, join to the usql.types catalog view on this column. |
| max_length | int? | Column's maximum length in bytes. -1 = Variable sized column such as columns of type string or byte[] or of a complex type. The value null is reserved for future use. |
Examples
The examples can be executed in Visual Studio with the Azure Data Lake Tools plug-in.
Query the usql.columns view
USE TestReferenceDB;
OUTPUT usql.columns
TO "/ReferenceGuide/CatalogViews/columns.txt"
USING Outputters.Tsv(outputHeader:true);
Query the usql.columns view with other catalog views
@columns =
SELECT "object" AS object_type,
o.name AS objectName,
c.*
FROM usql.columns AS c
JOIN usql.objects AS o
ON c.object_id_guid == o.object_id_guid
UNION ALL
SELECT "type" AS object_type,
t.name AS objectName,
c.*
FROM usql.columns AS c
JOIN usql.types AS t
ON c.object_id_guid == t.type_id_guid;
OUTPUT @columns
TO "/ReferenceGuide/CatalogViews/columns_objects_types.txt"
ORDER BY object_type, objectName, name
USING Outputters.Tsv(outputHeader:true);