MYSQL,Oracle,DB2,SQLServer4中数据库的分页写法

MySQL:

SELECT

          CHANNEL_ID,

          OPERATOR,

          ORGANIZATION_ID,

          BIZ_TYPE_CODE,

          SEAL_ID,

          count(DISTINCT OPERATION_LOG_ID) count

FROM

          SEAL_LOG

WHERE

           SEAL_ID != ''

GROUP BY

           CHANNEL_ID,

           OPERATOR,

           ORGANIZATION_ID,

           BIZ_TYPE_CODE,

           SEAL_ID

LIMIT 0,100

注:只需要用limit 开始编号，取的数量

Oracle:

SELECT

          *

FROM

 (

          SELECT

                     A .*, ROWNUM AS r

           FROM

                     (

                          SELECT

                                     CHANNEL_ID,

                                      OPERATOR,

                                     ORGANIZATION_ID,

                                     BIZ_TYPE_CODE,

                                     SEAL_ID,

                                     COUNT (DISTINCT OPERATION_LOG_ID) COUNT

                              FROM

                                       SEAL_LOG

                             WHERE

                                         SEAL_ID IS NOT NULL

                            GROUP BY

                                           CHANNEL_ID,

                                             OPERATOR,

                                            ORGANIZATION_ID,

                                            BIZ_TYPE_CODE,

                                             SEAL_ID

                               ) A

                       )

WHERE

 r > 0 AND r <= 100

注：第一对参数的非空判断，oracle中是is not null,其他三种数据库都可以用!=''

       在原有select的基础上做了两层select嵌套，第一层加上编号，第二层筛选，之所以第一层嵌套加编号，是因为group函数分组导致不能在直接查的时候加上编号（和SQL Server,DB2不同）

DB2：

SELECT * FROM(

                SELECT

                         rownumber() over() as rowid,

                        CHANNEL_ID,

                        OPERATOR,

                        ORGANIZATION_ID,

                        BIZ_TYPE_CODE,

                        SEAL_ID,

                        count(DISTINCT OPERATION_LOG_ID) count

                FROM

                        SEAL_LOG b

                WHERE

                        SEAL_ID != ''

                GROUP BY

                        CHANNEL_ID,

                        OPERATOR,

                        ORGANIZATION_ID,

                        BIZ_TYPE_CODE,

                SEAL_ID

        ) a

where rowid>0 and rowid <=2

注：和SQL SERVER一样，第一次查询的时候，就查询出编号，外面套一个SELECT用于筛选个数，不过和SQL SERVER不同的是，这里的OVER()里面可以为空，而SQL SERVER的OVER里面必须加排序字段。

SQL SERVER:

SELECT

           *

FROM

            (

              SELECT

                         row_number () OVER (ORDER BY SEAL_ID) AS rownumber,

                         CHANNEL_ID,

                          OPERATOR,

                         ORGANIZATION_ID,

                         BIZ_TYPE_CODE,

                         SEAL_ID,

                         COUNT (DISTINCT OPERATION_LOG_ID) COUNT

                   FROM

                         SEAL_LOG

                   WHERE

                         SEAL_ID != ''

                   GROUP BY

                         CHANNEL_ID,

                         OPERATOR,

                          ORGANIZATION_ID,

                         BIZ_TYPE_CODE,

                         SEAL_ID

                       ) a

WHERE  a.rownumber BETWEEN 0 AND 100

注：同DB2，不过OVER()函数里面必须要加排序字段，该字段是查询出来的字段，比如此处不能是ID(因为没查出来)

小结：

1:MYSQL,DB2，SQLSERVER的COUNT是一致的，Oracle不一致，区别在于非空判断，Oracle是is not null,别的都是!=’’

2:关于SQL SERVER,DB2的分页都是嵌套一次，第一次查询会查询出编号，但是ORACLE不行，因为Group函数的问题，ORACLE需要嵌套两次。