mssql - incorrect and incomplete DDL for tables with calculated columns and extended properties

System information:

• Operating system (distribution) and version: Windows 10
• DBeaver version: .3.5.202102141704
• Additional extensions

Connection specification:

• Database name and version: SQL Server 2019
• Driver name: information not available in connection properties
• Do you use tunnels or proxies (SSH, SOCKS, etc)?

Describe the problem you’re observing:

• calculated columns are shown as real colums
• extended properties are missing

Steps to reproduce, if exist:

create this table in SQL Server

CREATE TABLE [repo].[Parameter](
	[Parameter_name] [varchar](100) NOT NULL,
	[sub_Parameter] [nvarchar](128) NOT NULL,
	[Parameter_desciption] [nvarchar](1000) NULL,
	[Parameter_default_value] [sql_variant] NULL,
	[Parameter_value] [sql_variant] NULL,
	[Parameter_value__result_nvarchar]  AS (TRY_CAST(coalesce([Parameter_value],[Parameter_default_value]) AS [nvarchar](4000))),
	[Parameter_value__result_int]  AS (TRY_CAST(coalesce([Parameter_value],[Parameter_default_value]) AS [int])),
 CONSTRAINT [PK_Parameter] PRIMARY KEY CLUSTERED 
(
	[Parameter_name] ASC,
	[sub_Parameter] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [repo].[Parameter] ADD  DEFAULT ('') FOR [sub_Parameter]
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObjectColumn_guid', @value=N'11f37926-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'COLUMN',@level2name=N'Parameter_name'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObjectColumn_guid', @value=N'12f37926-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'COLUMN',@level2name=N'sub_Parameter'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObject_guid', @value=N'69cbc49c-3862-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'CONSTRAINT',@level2name=N'DF__Parameter__sub_P__18B6AB08'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObjectColumn_guid', @value=N'13f37926-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'COLUMN',@level2name=N'Parameter_desciption'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObjectColumn_guid', @value=N'14f37926-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'COLUMN',@level2name=N'Parameter_default_value'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObjectColumn_guid', @value=N'15f37926-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'COLUMN',@level2name=N'Parameter_value'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObjectColumn_guid', @value=N'16f37926-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'COLUMN',@level2name=N'Parameter_value__result_nvarchar'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObjectColumn_guid', @value=N'75b33a4a-426d-eb11-84e2-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'COLUMN',@level2name=N'Parameter_value__result_int'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObject_guid', @value=N'2690291c-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter', @level2type=N'CONSTRAINT',@level2name=N'PK_Parameter'
GO

EXEC sys.sp_addextendedproperty @name=N'RepoObject_guid', @value=N'2490291c-9d61-eb11-84dc-a81e8446d5b0' , @level0type=N'SCHEMA',@level0name=N'repo', @level1type=N'TABLE',@level1name=N'Parameter'
GO

compare with DDL, shown in dbeaver:

-- Drop table

-- DROP TABLE dhw_self.repo.[Parameter] GO

CREATE TABLE dhw_self.repo.[Parameter] (
	Parameter_name varchar(100) COLLATE Latin1_General_CI_AS NOT NULL,
	sub_Parameter nvarchar(128) COLLATE Latin1_General_CI_AS DEFAULT '' NOT NULL,
	Parameter_desciption nvarchar(1000) COLLATE Latin1_General_CI_AS NULL,
	Parameter_default_value sql_variant NULL,
	Parameter_value sql_variant NULL,
	Parameter_value__result_nvarchar nvarchar(4000) COLLATE Latin1_General_CI_AS NULL,
	Parameter_value__result_int int NULL,
	CONSTRAINT PK_Parameter PRIMARY KEY (Parameter_name,sub_Parameter)
) GO

missing extend properties could be OK But the calculated columns needs to be calculated columns

[aisbergde]

@kseniiaguzeeva You could delete (ignore) WITH ..., It does not matter for the calculated columns

the script is originally created when I create a script for any table directly in SSMS (SQL Server Management Studio)

This should be fine to test:

CREATE TABLE [repo].[Parameter](
	[Parameter_name] [varchar](100) NOT NULL,
	[sub_Parameter] [nvarchar](128) NOT NULL,
	[Parameter_desciption] [nvarchar](1000) NULL,
	[Parameter_default_value] [sql_variant] NULL,
	[Parameter_value] [sql_variant] NULL,
	[Parameter_value__result_nvarchar]  AS (TRY_CAST(coalesce([Parameter_value],[Parameter_default_value]) AS [nvarchar](4000))),
	[Parameter_value__result_int]  AS (TRY_CAST(coalesce([Parameter_value],[Parameter_default_value]) AS [int])),
 CONSTRAINT [PK_Parameter] PRIMARY KEY CLUSTERED 
(
	[Parameter_name] ASC,
	[sub_Parameter] ASC
)
) ON [PRIMARY]

You can also use any other table containing any calculated column.

BTW, the code above contains “normal” (not persisted) calculated column. But calculated columns in SQL Server can be also persisted. And it is important to keep this information, if it is persisted or not.

Full syntax: https://docs.microsoft.com/de-de/sql/t-sql/statements/create-table-transact-sql?view=sql-server-ver15

This is the part for a calculated column

<computed_column_definition> ::=
column_name AS computed_column_expression
[ PERSISTED [ NOT NULL ] ]
...

You can ignore the NOT NULL, it will be implicitly defined, but the PERSISTED is an important option which needs to keep.

[uslss]

verified