abstract public class Sql {
    public Sql(String table, Column[] columns;
    abstract public String generate();
}
public class CreateSql extends Sql {
    public CreateSql(String table, Column[] columns);
    @Override public String generate();
}
public class SelectSql extends Sql {
    public SelectSql(String table, Column[] columns);
    @Override public String generate();
}
public class InsertSql extends Sql {
    public InsertSql(String table, Column[] columns, Object[] fields);
    @Override public String generate();
    private String valuesList(Object[] fields, final Column[] columns);
}
public class SelectWithCriteriaSql extends Sql {
    public SelectWithCriteriaSql(String table, Column[] columns, Criteria criteria);
    @Override public String generate();
}
public class SelectWithMatchSql extends Sql {
    public SelectWithMatchSql(String table, Column[] columns, Column column, String pattern);
    @Override public String generate();
}
public class FindByKeySql extends Sql
        public FindByKeySql(String table, Column[] columns, String keyColumn, String keyValue);
        @Override public String generate();
}
public class PreparedInsertSql extends Sql {
    public PreparedInsertSql(String table, Column[] columns);
    @Override public String generate();
    private String placeholderList(Column[] columns);
}
public class Where {
    public Where(String criteria);
    public String generate();
}
public class ColumnList {
    public ColumnList(Column[] columns);
    public String generate();
}