From 5b5eb85938cc8be5820aad6d3158505ef34e5e64 Mon Sep 17 00:00:00 2001
From: Steve Clarke <84364906+s7clarke10@users.noreply.github.com>
Date: Thu, 17 Oct 2024 16:07:04 +1300
Subject: [PATCH] Updating CDC maintenance documentation.

---
 .bumpversion.cfg |  2 +-
 CHANGELOG.md     |  3 ++
 MS_CDC_SETUP.md  | 94 ++++++++++++++++++++++++++++++++++++++++++++++++
 pyproject.toml   |  2 +-
 4 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/.bumpversion.cfg b/.bumpversion.cfg
index 0a7bc534..b4a0fc3c 100644
--- a/.bumpversion.cfg
+++ b/.bumpversion.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 2.6.2
+current_version = 2.6.3
 parse = (?P<major>\d+)
 	\.(?P<minor>\d+)
 	\.(?P<patch>\d+)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fdb1e828..8b92ffe5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+# tap-mssql 2.6.3 2024-10-17
+* Updating CDC documentation with a packaged method to maintain CDC tables.
+
 # tap-mssql 2.6.2 2024-10-09
 * Resolving issue when a table has a primary key and unique key. Both unique and primary key
   columns were being identified as the primary key for the target table. Prioritising the
diff --git a/MS_CDC_SETUP.md b/MS_CDC_SETUP.md
index acd55d72..c1b9d8de 100644
--- a/MS_CDC_SETUP.md
+++ b/MS_CDC_SETUP.md
@@ -593,4 +593,98 @@ EXEC [sys].[sp_cdc_disable_table]
   @source_name   = @source_name,
   @capture_instance = @capture_instance_temp
 
+```
+
+## Code to manage structural changes (DDL) to tables being captured.
+
+The following code is a variant of the code above in a packaged form.
+
+This may assist the process of maintaining CDC tables when the base table has a structural change.
+
+```sql
+--Automated sqlserver-cdc-re-enrolled procedures.
+
+CREATE PROCEDURE [mydatabase].[DisableCDC]
+    @schema_name NVARCHAR(512),
+    @table_name NVARCHAR(512)
+AS
+BEGIN
+    DECLARE @capture_instance NVARCHAR(512) = @schema_name + '_' + @table_name;
+    EXEC sys.sp_cdc_disable_table
+    @source_schema = @schema_name,
+    @source_name = @table_name,
+    @capture_instance = @capture_instance
+END;
+GO
+CREATE PROCEDURE [mydatabase].[EnableCDC]
+    @schema_name NVARCHAR(512),
+    @table_name NVARCHAR(512)
+AS
+BEGIN
+    EXEC sys.sp_cdc_enable_table
+    @source_schema = @schema_name,
+    @source_name = @table_name,
+    @role_name = RoleChangeDataCapture,
+    @supports_net_changes = 1
+END;
+GO
+create procedure [mydatabase].[ReEnrollCDCTable]
+    @source_schema varchar(max),
+    @source_name varchar(max)
+as
+begin
+    declare @cdc_schema varchar(max) = 'cdc'
+    declare @column_list varchar(max)
+    declare @sql varchar(max)
+    declare @capture_instance varchar(max)
+    set @capture_instance = @source_schema + '_' + @source_name
+    declare @ct_table varchar(max)
+    set @ct_table = @capture_instance + '_ct'
+    declare @capture_instance_temp varchar(max)
+    set @capture_instance_temp = @capture_instance + '_temp'
+    declare @ct_table_temp varchar(max)
+    set @ct_table_temp = @capture_instance_temp + '_ct'
+    exec sys.sp_cdc_enable_table
+        @source_schema = @source_schema,
+        @source_name = @source_name,
+        @role_name = N'RoleChangeDataCapture',
+        @supports_net_changes = 1,
+        @capture_instance = @capture_instance_temp
+    select @column_list = stuff((
+        select ',' + column_name
+        from (
+            select ct.column_name
+            from information_schema.columns ct
+            inner join information_schema.columns ctt
+                on ct.column_name = ctt.column_name
+            where ct.table_name = @ct_table and ct.table_schema = @cdc_schema
+            and ctt.table_name = @ct_table_temp and ctt.table_schema = @cdc_schema
+        ) x
+        for xml path('')), 1, 1, '')
+    set @sql = 'insert into ' + @cdc_schema + '.' + @ct_table_temp +
+               '(' + @column_list + ') select ' + @column_list +
+               ' from ' + @cdc_schema + '.' + @ct_table
+    exec(@sql)
+    exec dbo.disablecdc @source_schema,@source_name;
+    exec dbo.enablecdc @source_schema,@source_name;
+    set @sql = 'insert into ' + @cdc_schema + '.' + @ct_table +
+               '(' + @column_list + ') select ' + @column_list +
+               ' from ' + @cdc_schema + '.' + @ct_table_temp
+    exec(@sql)
+    exec sys.sp_cdc_disable_table
+        @source_schema = @source_schema,
+        @source_name = @source_name,
+        @capture_instance = @capture_instance_temp
+end
+go
+
+--Example-cdc-re-enroll-tables
+
+-- Stop the CDC processing
+exec sp_cdc_stop_job
+-- Align CDC tables with new table structure
+exec mydatabase.ReEnrollCDCTable 'schema1','table_a'
+exec mydatabase.ReEnrollCDCTable 'schema2','table_b'
+-- Restart the CDC processing
+exec sp_cdc_start_job
 ```
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 0173a77a..ac3f44be 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "tap-mssql"
-version = "2.6.2"
+version = "2.6.3"
 description = "A pipelinewise compatible tap for connecting Microsoft SQL Server"
 authors = ["Rob Winters <wintersrd@gmail.com>"]
 license = "GNU Affero"