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Step-by-Step Guide to Migrating from MSSQL to MySQL

Migrating from MSSQL to MySQL involves transferring your database schema, tables, and data from one database management system to another. One also has to migrate the Triggers, procedures. The migration of Triggers, Stored procedures are quite difficult because of Syntax Changes, like for example if you are migrating from MSSQL to MySQL, in MSSQL the stored procedures would be written in T-SQL language, whereas, MySQL uses a different scripting language.

It's a time-consuming migration and requires a lot of planning and patience. It also requires the use of cross-database migration tools such as Data Loader or MySQL Migration Wizard - part of MySQL Workbench


You might also be interested in: Top 3 tools for converting MSSQL to MySQL


Here's a step-by-step guide to help you with the process:

database migration step by step


Step 1: Planning and Preparation

1.1 Analyze your MSSQL database: Take an inventory of the databases, tables, stored procedures, views, and other database objects in your MSSQL database.

anayze database 

1.2 Review your MySQL requirements: Make sure your target MySQL server meets the necessary requirements in terms of version, storage capacity, and configuration.

convert mssql to mysql

1.3 Backup your MSSQL database: Before starting the migration process, create a backup of your MSSQL database to ensure you have a safe copy in case anything goes wrong.

backup database before migration 

Step 2: Setting up MySQL Environment

2.1 Install MySQL: Download and install the MySQL server on the machine where you plan to migrate the database. Ensure you have the necessary permissions to create databases and tables.

2.2 Configure MySQL: Adjust the MySQL configuration settings as per your requirements. This may include adjusting memory allocation, buffer pool size, and other parameters to optimize MySQL's performance.


Step 3: Schema and Object Migration

3.1 Create the target database: In MySQL, create a new database with the desired name to hold your migrated data.

3.2 Migrate the schema: Extract the schema definition from your MSSQL database, including tables, indexes, constraints, and triggers. Recreate these objects in the MySQL database using SQL statements or a database migration tool.

3.3 Convert data types: Identify any data type differences between MSSQL and MySQL and make the necessary adjustments in your schema migration process. For example, MSSQL's "datetime" data type is equivalent to MySQL's "datetime" or "timestamp" data type.

Here's a comparison of some commonly used data types in MSSQL and their equivalents in MySQL:

Integer Data Types:
MSSQL: int, bigint, smallint, tinyint
MySQL: int, bigint, smallint, tinyint

Decimal and Numeric Data Types:
MSSQL: decimal, numeric
MySQL: decimal, numeric

Floating-Point Data Types:
MSSQL: float, real
MySQL: float, double

Character Data Types:
MSSQL: char, varchar, nchar, nvarchar
MySQL: char, varchar, char, varchar

Binary Data Types:
MSSQL: binary, varbinary
MySQL: binary, varbinary

Date and Time Data Types:
MSSQL: datetime, date, time
MySQL: datetime, date, time

Boolean Data Type:
MSSQL: bit
MySQL: tinyint(1) or bool

Text Data Types:
MSSQL: text, ntext
MySQL: text, longtext

It's important to note that while the data types listed above are commonly used, there may be additional data types available in both MSSQL and MySQL, depending on the specific versions and configurations. Additionally, the maximum allowed sizes and precision of these data types may vary between the two database systems.

During the migration process, it's crucial to carefully review and map the data types from the source (MSSQL) to the target (MySQL) to ensure compatibility and maintain data integrity.

3.4 Migrate stored procedures, views, and functions: If your MSSQL database includes stored procedures, views, or user-defined functions, recreate them in MySQL. Review and modify the syntax or logic as needed, as there may be differences in the SQL syntax between the two systems.


Step 4: Data Migration

4.1 Export data from MSSQL: Extract the data from your MSSQL database tables using tools like SQL Server Management Studio or the bcp utility, and save it in a suitable format such as CSV or SQL dump. 
                                See: How to export data from MSSQL using SQL Server Management Studio

4.2 Convert data formats: If required, convert the data formats from the MSSQL format to MySQL-compatible format. For example, you may need to adjust date formats or handle NULL values.

4.3 Import data into MySQL: Use the MySQL command-line tool or a graphical tool like MySQL Workbench to import the data into the corresponding tables in your MySQL database. Ensure the target tables are empty or properly truncated before the import.


Step 5: Testing and Verification

5.1 Validate the data: After the data migration, compare a sample of data between the MSSQL and MySQL databases to ensure the migration process was successful. Verify the row counts, primary keys, and other critical data points.

5.2 Test application compatibility: Update your application configuration to connect to the MySQL database and perform thorough testing to ensure your application works seamlessly with the new database.

See also: Testing and Validating data after database migration

Step 6: Post-Migration Tasks

6.1 Update connection strings and configurations: Once you have verified the successful migration and tested your application, update any relevant connection strings, configurations, or scripts to point to the MySQL database.

6.2 Implement data synchronization: If you need to keep the MSSQL database operational during the migration process, set up a data synchronization mechanism to ensure any changes made in MSSQL are replicated to the MySQL database until the complete migration is finished.

6.3 Decommission the MSSQL database: Once you are confident that the migration is successful and your application is functioning correctly with MySQL, decommission the MSSQL database.

Remember to thoroughly plan and test the migration process in a non-production environment before attempting it in a live environment. Database migrations can be complex, so it's crucial to have a solid backup strategy in place to avoid data loss or corruption.