Spring Data JDBC Firebird dialect not recognized

Question

I\'m trying to connect to Firebird database using Spring Data JDBC and Spring Boot. I\'ve created a simple app using Spring Tools. Spring Data JDBC doesn\'t recognize the di

Answer 1

The Spring Data JDBC library itself does not contain a Firebird dialect out of the box, so you need to provide one yourself. How to do this is documented in Annotation-based Configuration of the Spring Data JDBC documentation:

Dialects are resolved by JdbcDialectResolver from JdbcOperations, typically by inspecting Connection. You can let Spring auto-discover your Dialect by registering a class that implements org.springframework.data.jdbc.repository.config.DialectResolver$JdbcDialectProvider through META-INF/spring.factories. DialectResolver discovers dialect provider implementations from the class path using Spring’s SpringFactoriesLoader.

To be able to use Firebird, you will need to define three things:

1. A dialect
2. A dialect resolver
3. A config file for Spring to locate the dialect resolver

The dialect can be something like (note, this dialect assumes Firebird 3 or higher):

package spring.firebird;

import org.springframework.data.relational.core.dialect.AnsiDialect;
import org.springframework.data.relational.core.dialect.ArrayColumns;
import org.springframework.data.relational.core.dialect.LockClause;
import org.springframework.data.relational.core.sql.LockOptions;

public class FirebirdDialect extends AnsiDialect {

    public static final FirebirdDialect INSTANCE = new FirebirdDialect();

    @Override
    public LockClause lock() {
        return LOCK_CLAUSE;
    }

    @Override
    public ArrayColumns getArraySupport() {
        return ArrayColumns.Unsupported.INSTANCE;
    }

    private static final LockClause LOCK_CLAUSE = new LockClause() {

        @Override
        public String getLock(LockOptions lockOptions) {
            return "WITH LOCK";
        }

        @Override
        public Position getClausePosition() {
            return Position.AFTER_ORDER_BY;
        }
    };
}

A dialect resolver to return the dialect if the connection is to a Firebird database.

package spring.firebird;

import org.springframework.data.jdbc.repository.config.DialectResolver;
import org.springframework.data.relational.core.dialect.Dialect;
import org.springframework.jdbc.core.ConnectionCallback;
import org.springframework.jdbc.core.JdbcOperations;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.Locale;
import java.util.Optional;

public class FirebirdDialectResolver implements DialectResolver.JdbcDialectProvider {

    @Override
    public Optional getDialect(JdbcOperations operations) {
        return Optional.ofNullable(
                operations.execute((ConnectionCallback) FirebirdDialectResolver::getDialect));
    }

    private static Dialect getDialect(Connection connection) throws SQLException  {
        DatabaseMetaData metaData = connection.getMetaData();
        String name = metaData.getDatabaseProductName().toLowerCase(Locale.ROOT);
        if (name.contains("firebird")) {
            return FirebirdDialect.INSTANCE;
        }
        return null;
    }
}

Finally, you need to define a resource in META-INF with the name spring.factories, this file must contain the line:

org.springframework.data.jdbc.repository.config.DialectResolver$JdbcDialectProvider=spring.firebird.FirebirdDialectResolver

This allows Spring Data JDBC to discover the dialect resolver and use it.