README.md

MySQL-to-MSSQL

This is a simple server for synchronizing changes (CUD operations) from MySQL source database to MSSQL target database.

The architecture is simple:

1. parser: listen to changes from source db (via binlog)
2. changes will be logged into an embedded database
3. syncer: scan the log store & sync logged events to target db on a fixed interval

DEMO:

MYSQL

1. Set up local MYSQL instance with user root/root
2. Use the staff table in sakila schema that comes with MySQL 8.0 installation package (demo db)

MSSQL

1. Set up local MSSQL instance (2008+)

2. Enable TCP/IP in Configuration Manager

   

3. Create table Staff with same column names as MYSQL

   CREATE TABLE [dbo].[Staff](
       [staff_id] int NOT NULL primary key,
       [first_name] varchar(50) NOT NULL,
       [last_name] varchar(50) NOT NULL,
       [address_id] smallint NOT NULL,
       [picture] varbinary(max) NULL,
       [email] varchar(50) NULL,
       [store_id] smallint NOT NULL,
       [active] bit NOT NULL,
       [username] varchar(50) NULL,
       [password] varchar(50) NULL,
       [last_update] [datetime] NOT NULL,
   )
   ALTER TABLE [dbo].[Staff] SET (LOCK_ESCALATION = AUTO)

GO

1. Install go 1.14 amd64. Note that this library has not work with go >=1.15 yet, and it does not support 32-bit platforms ⚠️

2. Clone this repo to local machine, example: d:\demo

3. CD into directory (cd d:\demo)

4. Execute go run . It should start the Echo server

5. Send a POST request to /struct/put to let server knows about the table structure. For details about type enum, see db/types.go

   //deliberately removed "username" & "password" from the request, so these 2 fields won't be synced
   {
       "table":"staff",
       "columns": [
           {
               "name": "staff_id",
               "type": 1,
               "is_primary": true // currently a PK must be defined, otherwise server won't know how to handle update/delete
           },
           {
               "name": "first_name",
               "type": 5
           },
           {
               "name": "last_name",
               "type": 5
           },
           {
               "name": "picture",
               "type": 18
           },
           {
               "name": "address_id",
               "type": 1
           },
           {
               "name": "store_id",
               "type": 1
           },
           {
               "name": "email",
               "type": 6
           },
           {
               "name": "last_update",
               "type": 9
           },
           {
               "name": "active",
               "type": 7
           }
       ]
   }

6. Send a POST request with MySQL db info to /parser/start to start listening for changes

   {
       "server_id": 1,
       "addr": "127.0.0.1:3306",
       "user": "root",
       "password": "root",
       "use_decimal": true,
       "include_table_regex": ["sakila\\.staff"] //listen to changes from sakila.staff table only!
   }

7. Send another POST request with MSSQL db info to /syncer/start to start syncing changes received from parser

   {
       "server": "127.0.0.1",
       "database": "master", //where Staff table is
       "log": 63, //full logging
       "appname": "mysql-to-mssql" //the programe_name in dm_exec_sessions
   }

🔥 Make changes & see sync 🔥

FAQ:

1. Why not SSIS?

• No real time support
• Incremental load requires something like lastupdated column from source table

2. Why not trigger?

• Hard to maintain, you may not have full control to this trigger
• SQL Developers might be unaware of this side effect
• Slower performance (for example, trigger fires whenever a row is updated, whereas binlog only capture the final commited data once)