package ca.krasnay.sqlbuilder;

import javax.sql.DataSource;

/**

* Interface representing a SQL dialect. Dialects can modify SQL queries in

* database server-specific ways.

*

* @author John Krasnay <john@krasnay.ca>

*/

public interface Dialect {

/**

* Returns a SQL statement that returns the number of rows that would be

* returned by another select.

*

* @param sql

* Inner select statement, i.e. the one that returns the rows

* themselves.

*/

public String createCountSelect(String sql);

/**

* Returns a SQL statement that returns a limited number of rows from an

* inner query. Note that the inner select should include an ORDER BY clause

* that strictly orders the result set; otherwise, some database servers may

* return pages inconsistently.

*

* @param sql

* Inner query that would return the full result set.

* @param limit

* Maximum number of rows to return.

* @param offset

* Index into the result set of the first row returned.

*/

public String createPageSelect(String sql, int limit, int offset);

/**

* Returns an integer supplier representing a database sequence.

*

* @param dataSource

* DataSource where the sequence exists.

* @param sequenceName

* Name of the sequence.

*/

public Supplier<Integer> getSequence(DataSource dataSource, String sequenceName);

}