.alter-merge table
The .alter-merge table
command:
- Secures data in existing columns
- Adds new columns,
docstring
, and folder to an existing table - Must run in the context of a specific database that scopes the table name
- Requires Table Admin permission
Syntax
.alter-merge
table
TableName (columnName:columnType[, ...]) [with
(
[docstring
=
Documentation] [,
folder
=
FolderName] )
]
Parameters
Name | Type | Required | Description |
---|---|---|---|
TableName | string | ✓ | The name of the table to alter. |
columnName:columnType | string | ✓ | The name of an existing or new column mapped to the type of data in that column. The list of these mappings defines the output column schema. |
Documentation | string | Free text describing the entity to be added. This string is presented in various UX settings next to the entity names. | |
FolderName | string | The name of the folder to add to the table. |
Note
If you try to alter a column type, the command will fail. Use .alter column
instead.
Tip
Use .show table [TableName] cslschema
to get the existing column schema before you alter it.
How the command affects the data
- Existing data won't be modified or deleted
- New columns will be added to the end of the schema
- Data in new columns is assumed to be null
Examples
.alter-merge table MyTable (ColumnX:string, ColumnY:int)
.alter-merge table MyTable (ColumnX:string, ColumnY:int) with (docstring = "Some documentation", folder = "Folder1")
See also
Use the .alter
table command when you wish to further redefine the table settings. For more information, see .alter table.