content: /**
   * Copyright &copy; 2012-2016 <a href="https://github.com/HuangBingGui/jeespring">jeespring</a> All rights reserved.
   */
  package com.jeespring.common.persistence.dialect;
  
  import com.jeespring.common.persistence.dialect.Dialect;
  
  /**
   * MSSQLServer 数据库实现分页方言
   *
   * @author poplar.yfyang
   * @version 1.0 2010-10-10 下午12:31
   * @since JDK 1.5
   */
  public class SQLServerDialect implements Dialect {
  
      public boolean supportsLimit() {
          return true;
      }
  
      static int getAfterSelectInsertPoint(String sql) {
          int selectIndex = sql.toLowerCase().indexOf("select");
          final int selectDistinctIndex = sql.toLowerCase().indexOf("select distinct");
          return selectIndex + (selectDistinctIndex == selectIndex ? 15 : 6);
      }
  
      public String getLimitString(String sql, int offset, int limit) {
          return getLimit(sql, offset, limit);
      }
  
      /**
       * 将sql变成分页sql语句,提供将offset及limit使用占位符号(placeholder)替换.
       * <pre>
       * 如mysql
       * dialect.getLimitString("select * from user", 12, ":offset",0,":limit") 将返回
       * select * from user limit :offset,:limit
       * </pre>
       *
       * @param sql    实际SQL语句
       * @param offset 分页开始纪录条数
       * @param limit  分页每页显示纪录条数
       * @return 包含占位符的分页sql
       */
      public String getLimit(String sql, int offset, int limit) {
          if (offset > 0) {
              throw new UnsupportedOperationException("sql server has no offset");
          }
          return new StringBuffer(sql.length() + 8)
                  .append(sql)
                  .insert(getAfterSelectInsertPoint(sql), " top " + limit)
                  .toString();
      }
  
  
  }
  