![]() If you are using triggers purely to create primary key values, you can leave those out as well. You don’t need sequences in MySQL, so you don’t have to include these if you export your Oracle database with SQL Developer. REG_DATE DATETIME DEFAULT CURRENT_TIMESTAMP A MySQL script could look like this: CREATE TABLE EVENTS SYSDATE is an Oracle-specific function that you need to replace with the equivalent CURRENT_TIMESTAMP. ![]() To create these tables in MySQL, you need to remove the double quotes and change the datatypes. SQL Developer exports tables with double quotes, like this:. Below is an example of an export from SQL Developer of a simple database containing many of the normal Oracle schema objects, and how they map to MySQL. You can also export your Oracle database to a file using Oracle SQL Developer and then make the necessary adjustments to create an equivalent MySQL database. Searching the Internet will also produce a number of third-party tools that purport to be able to migrate your database from Oracle to MySQL. From there, you can use the MySQL migration wizard, which does support migrating from MS SQL Server. Microsoft will be happy to help you migrate from Oracle to SQL Server with the Microsoft SQL Server Migration Assistant. There is also a generic migration that can be used to migrate “most ODBC compliant databases.” However, this also cannot be used to migrate from Oracle to –MySQL-the wizard will connect but not see any database object to migrate. Since MySQL is owned by Oracle, there is obviously no migration from Oracle to MySQL. This wizard helps you migrate from MS SQL Server, MS Access, PostgreSQL, and Sybase. MySQL Workbench comes with a database migration wizard. MySQL has no concept of anchored variables with %TYPE and %ROWTYPE. MySQL has basic control structures like IF-THEN-ELSE, WHILE and REPEAT loops, but you will look in vain for a FOR loop construct. ![]() There are a number of syntactic differences – for example, PL/SQL EXCEPTION branches are handled in MySQL with DECLARE HANDLER. While you have the same table trigger capabilities in MySQL as in Oracle (BEFORE/AFTER, row or table), you don’t have all the other triggers Oracle offers, like DDL triggers, ON-LOGON etc. If you are using many built-in packages, it will become very hard to move to MySQL. The programming language in MySQL is much simpler than PL/SQL, and MySQL does not have anything like the capability of the built-in packages in Oracle. You need to use one of the INT types for primary columns that use AUTO_INCREMENT. MySQL has lots of different datatypes, from 3-digit TINYINT to 19-digit BIGINT. The easy conversion is to turn every Oracle DATE into a MySQL DATETIME, but if you never need the time element, it makes sense to use MySQL DATE for these values. Note that the MySQL DATE variable only has the date part and no time. The data types are different between Oracle and MySQL, but can generally be mapped easily. The security model in MySQL is generally much simpler than in Oracle, so if you have detailed and/or complicated security in an Oracle application, it will be hard to migrate to MySQL. So users need to be granted access to schemas/databases. In MySQL, the word DATABASE is synonymous with SCHEMA and is decoupled from users. In Oracle, you have one database with many schemas that are also users. This means that you also do not have package variables, but will have to use session-scoped user defined variables to store values.ĭatabases, schemas, and users also work differently. ![]() MySQL does not have anything corresponding to PL/SQL packages, only functions and procedures. This eliminates the primary key trigger that was necessary until Oracle 12. For example, MySQL does not have sequences but instead allows columns to be defined as AUTO_INCREMENT. ![]() Many of the features of Oracle are also available in MySQL:įor some Oracle features, MySQL has equivalent functionality but implemented differently. But if you have an existing database, you need to investigate carefully if it makes sense to move. If you are building your application from scratch, most projects can start with any relational database. With the loss of the Oracle Standard Edition One license, and the free Oracle Express Edition database stuck at the old 11g Release 2 from 2014, many smaller projects are considering whether MySQL might be an alternative.
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