You specify the database dialect in Hibernate using the hibernate.dialect property. This tells Hibernate which SQL dialect to use so it can generate database-specific SQL statements compatible with your database system (e.g., MySQL, PostgreSQL, Oracle).
🔹 Why is dialect important?
- Different databases use different SQL syntax, functions, and datatypes.
- By setting the correct dialect, Hibernate knows:
✅ Which SQL features to use.
✅ How to generate DDL (e.g., table creation).
✅ How to write compatible SQL statements.
🔹 How to specify it in hibernate.cfg.xml:
<property name="hibernate.dialect">org.hibernate.dialect.MySQL8Dialect</property>
🔹 How to specify it in Spring Boot (application.properties):
spring.jpa.database-platform=org.hibernate.dialect.Oracle12cDialect
🔹 Examples of common dialects:
- MySQL 8:
org.hibernate.dialect.MySQL8Dialect - PostgreSQL:
org.hibernate.dialect.PostgreSQLDialect - Oracle 12c:
org.hibernate.dialect.Oracle12cDialect - SQL Server:
org.hibernate.dialect.SQLServerDialect - H2 (in-memory):
org.hibernate.dialect.H2Dialect
🔹 Important note:
If you don’t specify hibernate.dialect, Hibernate will try to guess it from the JDBC metadata, but it’s best practice to set it explicitly for consistent behavior.
The hibernate.dialect property instructs Hibernate how to generate SQL specific to your database — and setting it correctly ensures your app runs smoothly on your chosen RDBMS.