sql - SQL 使用我的 sql 中的计数

Question

您好，我有这个 SQL 语句，我正在尝试获取计数并查看它有多少条记录。我知道我可以从表和 where 子句中执行 select count(*)，但我担心我可能会丢失一些记录，或者会显示更多记录。我可以使用我的选择语句中的所有这些列进行计数吗？我想我可能需要使用 With 子句之类的东西。有什么帮助吗？

select hdr.ACCESS_IND,        
        hdr.SID,    
         hdr.CLLI,    
         hdr.DA,    
         hdr.TAPER_CODE,    
         hdr.CFG_TYPE  as CFG_TYPE,    
         hdr.IP_ADDR,    
         hdr.IOS_VERSION,    
         hdr.ADMIN_STATE,    
         hdr.WIRE_CENTER,    
         substr(hdr.SID_IO_PRI, 1, 8)    PRI_IO_CLLI,    
         substr(hdr.SID_IO_SEC, 1, 8)    SEC_IO_CLLI,    
         hdr.VHO_CLLI ,   
         hdr.CFG_TYPE ,
         dtl.MULTIPURPOSE_IND,
         lkup.code3 as shelf_type,
         dtl.access_ind
     from      RPT_7330_HDR    hdr  
     INNER JOIN   RPT_7330_DTL dtl on hdr.EID = dtl.EID
     INNER JOIN CODE_LKUP2 lkup ON LKUP.CODE1 = DTL.ACCESS_IND
     where    LKUP.CATEGORY='ACCESS_MAPPING' and  hdr.DT_MODIFIED = (select DT_MODIFIED    
                    from     LS_DT_MODIFIED    
                    where NAME = 'RPT_7330_HDR') 
                    and LKUP.CATEGORY='ACCESS_MAPPING'
                    and  hdr.ACCESS_IND;

Answer 1

你可以这样做：

select count(*) from (
    select hdr.ACCESS_IND,        
        hdr.SID,    
         hdr.CLLI,    
         hdr.DA,    
         hdr.TAPER_CODE,    
         hdr.CFG_TYPE  as CFG_TYPE,    
         hdr.IP_ADDR,    
         hdr.IOS_VERSION,    
         hdr.ADMIN_STATE,    
         hdr.WIRE_CENTER,    
         substr(hdr.SID_IO_PRI, 1, 8)    PRI_IO_CLLI,    
         substr(hdr.SID_IO_SEC, 1, 8)    SEC_IO_CLLI,    
         hdr.VHO_CLLI ,   
         hdr.CFG_TYPE ,
         dtl.MULTIPURPOSE_IND,
         lkup.code3 as shelf_type,
         dtl.access_ind
     from      RPT_7330_HDR    hdr  
     INNER JOIN   RPT_7330_DTL dtl on hdr.EID = dtl.EID
     INNER JOIN CODE_LKUP2 lkup ON LKUP.CODE1 = DTL.ACCESS_IND
     where    LKUP.CATEGORY='ACCESS_MAPPING' and  hdr.DT_MODIFIED = (select DT_MODIFIED    
                    from     LS_DT_MODIFIED    
                    where NAME = 'RPT_7330_HDR') 
                    and LKUP.CATEGORY='ACCESS_MAPPING'
                    and  hdr.ACCESS_IND
) v;