一段拼装sql的小代码

* * 单表查询 * * className：实体类的名字 * vals：查询的属性 * pNames：条件的名字 * pVals：条件的值 */ @Override public List<Object> get(String className,String[] vals,Object[] pNames,Object[] pVals){ if(StringUtils.isEmpty(className)) { throw new NullParameterException("实体类的名字没有写"); } StringBuffer hql = new StringBuffer(); if(vals.length != 0) { hql.append("SELECT "); for(int i=0; i<vals.length;i++) { hql.append("p."); hql.append(vals[i]); if(i != vals.length-1) { hql.append(", "); } } } hql.append(" FROM "); hql.append(className); hql.append(" p"); if(pNames.length>0 && pVals.length>0 && pNames.length==pVals.length) { hql.append(" WHERE "); for(int i=0;i<pNames.length;i++) { hql.append(" p."); hql.append(pNames[i]); hql.append("="); hql.append(pVals[i]); if(i<pNames.length-1) { hql.append(" AND "); } } } System.out.println(hql.toString()); return null; }

1. userDao.get("VerificationCode", new String[] {"val1","val2"}, new Object[]{"p1","p2","p3"}, new Object[] {"pv1","pv2","pv3"});
输出：SELECT p.val1, p.val2 FROM VerificationCode p WHERE  p.p1=pv1 AND  p.p2=pv2 AND  p.p3=pv3

　2. userDao.get("VerificationCode", new String[] {}, new Object[]{"p1","p2","p3"}, new Object[] {"pv1","pv2","pv3"});

输出： FROM VerificationCode p WHERE  p.p1=pv1 AND  p.p2=pv2 AND  p.p3=pv3

3. userDao.get("VerificationCode", new String[] {}, new Object[]{}, new Object[] {});

  输出：FROM VerificationCode p

　

　4.userDao.get("VerificationCode", new String[] {"p1"}, new Object[]{}, new Object[] {});

　输出：SELECT p.p1 FROM VerificationCode p

 

 

一段拼装sql的小代码

标签：