ibatis in 1000 僅供參考

 SQL的動態where 拼寫實現

	/**
	 * or　拼 in(num個)
	 * 列名
	 * list
	 * in中多少個元素
	 */
	public String createSql(String col, List<String> partners, int num) {

		StringBuffer sb = new StringBuffer();
		
		// COL in (1,2,3,4,5,6) 
		// or
		// COL in (7,8,9,10,11,12)
		
		// ->
		// COL in (
		// 1,2,3,4,5,6) 
		// or COL in (
		// 7,8,9,10,11,12)
		sb.append(col + " in (");
		
		int size = partners.size();
		for (int i=1;i<(size+1);i++) {
			
			int shang = i/num;
			int yushu = i%num;
			
			
			if(yushu == 0){
				
				sb.append("'" + partners.get(i-1) + "')");
				
				if((i!=size)&&(shang != 0)){
					sb.append(" or ");
					sb.append(col + " in (");
				}
			}else{
				
				if(i==size){
					
					sb.append("'" + partners.get(i-1) + "')");
				}else{
					
					sb.append("'" + partners.get(i-1) + "',");
				}
				
			}
			
		}
		
		
		return sb.toString();
	}

測試用例

@Test
	public void test() {

		List partners = new ArrayList();
		partners.clear();
		for (int i = 1; i < 9; i++) {
			
			partners.add(String.valueOf(i));
		}
		
		String s = createSql("COL", partners, 10);
		System.out.println(s);

		/////////////////////////////////////////////////////////////////////////////////
		
		partners.clear();
		for (int i = 1; i < 10; i++) {
			
			partners.add(String.valueOf(i));
		}
		
		s = createSql("COL", partners, 10);
		System.out.println(s);
		
		/////////////////////////////////////////////////////////////////////////////////
		
		partners.clear();
		for (int i = 1; i < 11; i++) {

			partners.add(String.valueOf(i));
		}

		s = createSql("COL", partners, 10);
		System.out.println(s);
		
		/////////////////////////////////////////////////////////////////////////////////
		
		partners.clear();
		for (int i = 1; i < 12; i++) {

			partners.add(String.valueOf(i));
		}

		s = createSql("COL", partners, 10);
		System.out.println(s);
		
		/////////////////////////////////////////////////////////////////////////////////
				
		partners.clear();
		for (int i = 1; i < 13; i++) {
		
			partners.add(String.valueOf(i));
		}
		
		s = createSql("COL", partners, 10);
		System.out.println(s);
		
		/////////////////////////////////////////////////////////////////////////////////
		
		partners.clear();
		for (int i = 1; i < 20; i++) {
		
			partners.add(String.valueOf(i));
		}
		
		s = createSql("COL", partners, 10);
		System.out.println(s);
		
		/////////////////////////////////////////////////////////////////////////////////
		
		partners.clear();
		for (int i = 1; i < 21; i++) {
		
			partners.add(String.valueOf(i));
		}
		
		s = createSql("COL", partners, 10);
		System.out.println(s);
		
		/////////////////////////////////////////////////////////////////////////////////
		
		partners.clear();
		for (int i = 1; i < 22; i++) {
		
			partners.add(String.valueOf(i));
		}
		
		s = createSql("COL", partners, 10);
		System.out.println(s);
		
	}

實行結果

COL in ('1','2','3','4','5','6','7','8')
COL in ('1','2','3','4','5','6','7','8','9')
COL in ('1','2','3','4','5','6','7','8','9','10')
COL in ('1','2','3','4','5','6','7','8','9','10') or COL in ('11')
COL in ('1','2','3','4','5','6','7','8','9','10') or COL in ('11','12')
COL in ('1','2','3','4','5','6','7','8','9','10') or COL in ('11','12','13','14','15','16','17','18','19')
COL in ('1','2','3','4','5','6','7','8','9','10') or COL in ('11','12','13','14','15','16','17','18','19','20')
COL in ('1','2','3','4','5','6','7','8','9','10') or COL in ('11','12','13','14','15','16','17','18','19','20') or COL in ('21')