針對oracle中in操作超過1000個參數 會拋異常 處理實例

1.先貼一個工具類OracleSQUtils，此類目的是爲了將數千個參數，按指定等分切片，最後用or進行拼接sql。

/**
 * 將千條參數切成等分拼sql查詢，提高查詢效率
 * @author Fantasy
 */
public class OracleSQUtils {

    /**
     * @param ids 存儲多個id的List集合
     * @param count 將多個id按count切成等分拼接
     * @param field 數據庫表對應字段
     * @return 返回拼接語句 如 id in (1,2,3....1000) or id in (1001,1002,1003....2000) or .... 
     */
    public static String getOracleSQLIn(List<?> ids, int count, String field) {
        count = Math.min(count, 1000);
        int len = ids.size();
        int size = len % count;
        if (size == 0) {
            size = len / count;
        } else {
            size = (len / count) + 1;
        }
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < size; i++) {
            int fromIndex = i * count;
            int toIndex = Math.min(fromIndex + count, len);
            //System.out.println(ids.subList(fromIndex, toIndex));
            String productId = StringUtils.defaultIfEmpty(StringUtils.join(ids.subList(fromIndex, toIndex), "','"), "");
            if (i != 0) {
                builder.append(" or ");
            }
            builder.append(field).append(" in ('").append(productId).append("')");
        }
        return StringUtils.defaultIfEmpty(builder.toString(), field + " in ('')");
    }


}

2.mybatis中sql的xml文件寫法配置：

<select id="querySomeInfoByIds" resultType="HashMap" parameterType="HashMap">
select dept_id,dept_name from dept a
where 1=1

<!--優化前：基於oracle數據庫做in查詢時，下面的通常寫法，當deptIds達到1000個以上時，oracle會報錯 -->
<if test="deptIds!= null">
    AND a.DEPT_ID IN
    <foreach item="item" index="index" collection="deptIds" open="(" separator="," close=")">  
      #{item}   
    </foreach>  
</if>

<!-- 優化後：將傳入的多個id在業務代碼中按適當等分拼接好傳入mybatis文件中，提升查詢效率和避開超過1000個id時oracle數據庫拋異常 -->
and ( ${deptIds} )

<!-其它普通參數->
<if test="param!= null and param!= ''">
    AND a.param =#{param}
</if>
....
</select>

3.業務代碼處理參數如下：

//deptIdList 中存儲數千個deptId
String deptIds=OracleSQUtils.getOracleSQLIn(deptIdList,1000,"a.DEPT_ID");
HashMap<String,Object> params=new HashMap<String,Object>();
params.put("deptIds",deptIds);
List<HashMap<String,Object>> resultList=deptService.querySomeInfoByIds(params);