BetterSQLServer2012Dialect.java

/*
 * Copyright 2026 Global Crop Diversity Trust
 * Licensed under the Apache License, Version 2.0
 * See LICENSE file in project root folder or http://www.apache.org/licenses/LICENSE-2.0
 */

package org.gringlobal.custom.hibernate;

import org.hibernate.dialect.SQLServer2012Dialect;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.type.DoubleType;
import org.hibernate.type.StandardBasicTypes;

/**
 * The Class BetterSQLServer2012Dialect.
 */
public class BetterSQLServer2012Dialect extends SQLServer2012Dialect {

	/**
	 * Adds missing functions to SQLServer dialect
	 */
	public BetterSQLServer2012Dialect() {
		super();
		registerFunction("stddev", new StandardSQLFunction("stdev", DoubleType.INSTANCE));
		registerKeyword("day"); // Needed for DATEDIFF(DAY, ...) as an unquoted keyword
		/* WARNING This does not work in @Formula expressions. Those are pure SQL. Hibernate 6 may have a solution. */
		registerFunction("datediff", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "datediff(day, ?1, ?2)"));

		// Needed for OFFSET 0 ROWS FETCH FIRST 1 ROWS ONLY
		registerKeyword("offset");
		registerKeyword("fetch");
		registerKeyword("first");
		registerKeyword("rows");
		registerKeyword("only");
	}

}