Migrating from MySQL to SQL Server involves transferring your database schema, data, and application code from the source to the target DBMS. This guide explores the migration process and provides tips for selecting the right MySQL to SQL Server converter.
Here are the general steps to migrate your database:
- Assess the MySQL database: Understand the size, complexity, and dependencies of the source MySQL database. Identify any MySQL-specific features or functionalities that may require adjustments during the migration.
- Plan the migration: Create a migration plan that outlines the timeline, required resources, and necessary steps for the MySQL to SQL Server migration. Consider factors like data volume, downtime restrictions, and potential risks. Plan a maintenance window or downtime period to switch the production environment to SQL Server.
- Set up the SQL Server environment: Install and configure SQL Server on the target server or use Azure SQL in the cloud. Ensure you have the necessary permissions and access grants on both MySQL and SQL Server to perform the migration.
- Schema migration: Convert the database schema, including tables, views, stored procedures, functions, and other MySQL database objects, to SQL Server-compatible equivalents. Pay attention to proper type mapping and handling of keywords. Ensure that data types, constraints, and indexes are compatible with SQL Server.
- Data migration: Transfer the data from MySQL to SQL Server. You can use tools like the SQL Server Migration Assistant (SSMA), write scripts, or employ data integration tools for this task. Perform thorough testing to verify data integrity and consistency.
- Code migration: Review and modify any application code that interacts with the database. Adapt SQL queries or statements specific to MySQL syntax or behavior to be compatible with SQL Server. Pay attention to translating MySQL-specific built-in functions to their SQL Server equivalents.
- Testing and validation: Perform comprehensive testing to ensure the functionality, performance, and accuracy of the migrated SQL Server database. Test various scenarios, including data retrieval, data manipulation, and application workflows.
- Application layer: Update application configurations, connection strings, and other relevant settings to point to the new SQL Server database.
- Post-migration tasks: After the migration, monitor the SQL Server environment for any issues, performance bottlenecks, or errors. Optimize the database if necessary and update any documentation.
Type Mapping.MySQL and SQL Server have similar data types, but some require special attention during conversion. Here are notable data type mappings from MySQL to SQL Server:
BIT(n) -> BINARY(n/8)
BLOB(n) -> VARBINARY(max)
BOOLEAN, BOOL -> BIT
DOUBLE -> FLOAT
FIXED(p,s) -> DECIMAL(p,s)
FLOAT8 -> BINARY_DOUBLE
LONGBLOB -> VARBINARY(max)
LONGTEXT -> VARCHAR(max)
MEDIUMBLOB -> VARBINARY(max)
MEDIUMINT -> INT
MEDIUMTEXT -> VARCHAR(max)
REAL -> DOUBLE PRECISION
TEXT -> VARCHAR(max)
TIMESTAMP(p) -> DATETIME2(p)
TINYBLOB ->VARBINARY(255)
TINYINT -> SMALLINT
TINYTEXT ->VARCHAR(255)
YEAR[(2 | 4)] -> NUMERIC(4)
Additionally, convert MySQL’s AUTO_INCREMENT field property to SQL Server’s IDENTITY.
SQL Conversion
One of the top challenges in MySQL to SQL Server migration is converting SQL code in views, stored procedures, functions, and triggers. Be aware of differences in SQL syntax and behavior between the two platforms. For example, MySQL’s limited queries with “SELECT … LIMIT” should be converted to “SELECT TOP” in SQL Server. Ensure that all selected columns in “SELECT … GROUP BY” queries are either in the “GROUP BY” clause or part of an aggregation function in SQL Server. Specific MySQL built-in functions must be replaced by MS SQL equivalents.
SSMA for MySQL
As evident from the previous guide, migrating a MySQL database to MS SQL is a complex task. Fortunately, there are helpful software tools available to automate most of the migration steps.
The primary tool recommended is the Microsoft SQL Server Migration Assistant (SSMA) for MySQL. This tool assists in migrating MySQL databases to any version of SQL Server, including Azure SQL, starting from 2012. It provides a range of features to facilitate the migration process:
- Establish connections: SSMA allows you to connect to the source MySQL database and the destination MS SQL or Azure SQL database.
- Migrate database entries: SSMA helps migrate MySQL database entries, including metadata, to their equivalent representations in SQL Server or Azure SQL.
- Load entries into the database: After converting the entries, SSMA enables you to load them into the SQL Server or Azure SQL database.
- Migrate data: SSMA facilitates the migration of data from MySQL tables to the corresponding MS SQL tables or Azure SQL tables.
To use SSMA, download and install the latest version from the official Microsoft website. Create a new SSMA project by selecting “File” > “New Project” in the tool. In the project window, right-click on “Connect to MySQL” and enter the necessary connection details for your MySQL database, such as server name, port, username, and password. Click “Connect” to establish the connection.
Once connected, configure SSMA for MySQL conversion settings by accessing the “Project Settings” option in the project window. This allows you to specify options related to data type mapping, schema and object conversion, and other migration preferences. Review and modify these settings according to your requirements.
Next, convert the required MySQL schemas into the MS SQL or Azure SQL format. Right-click on the MySQL database and select “Convert Schema.” This step converts the MySQL schema objects to their corresponding MS SQL format based on the configured conversion settings. After the schema conversion, review the conversion report to identify any issues or warnings. Address them by manually modifying the schema or adjusting the conversion settings as needed.
After converting the schema, migrate the data by right-clicking on the MySQL database and selecting “Migrate Data.” This step transfers the data from the MySQL tables to the appropriate MS SQL or Azure SQL tables. SSMA offers options to migrate all data or specify a subset based on filtering criteria. Once the data migration is complete, thoroughly test the integrity and consistency of the migrated data in MS SQL. Ensure that the migrated database functions as expected.
Commercial Converters
Although SSMA simplifies the migration process, it still requires several steps to configure and execute. For those seeking a fully automated solution, consider using commercial MySQL to SQL Server converter. These tools are specifically designed to streamline complex migrations with just a few button clicks. One such tool is the MySQL to SQL Server converter developed by Intelligent Converters software vendor.
Key benefits of the MySQL to SQL Server converter include:
- Support for all modern versions of MySQL and SQL Server, including forks like MariaDB, Perconaand DBaaS variations like Azure SQL, Amazon RDS.
- Conversion of schemas, data, indexes, constraints, foreign keys, and views.
- High-performance data migration using bulk reading and writing techniques.
- Option to modify the name, type, and other properties of each column and exclude specific columns from the migration.
- Ability to convert a MySQL database into a T-SQL script file when a direct connection to the target DBMS is unavailable.
- Option to merge and synchronize existing MS SQL or Azure SQL databases with MySQL data.
- Ability to filter data for conversion and combine multiple tables into a single one using SELECT queries.
