杭州化工网站建设大学生ppt自我介绍幻灯片

此处的中文乱码和mysql的库表 编码 latin utf 无关。

直接上案例。

有时候我们需要自定义一列，有时是汉字有时是字母，结果遇到这种情况了。

说实话看到这真是糟心。这谁受得了。

单独select 没有任何问题。

这是怎么回事呢？ 经过一番检查，发现有个地方类似与 "境内"  as col但是没乱码，

此时怀疑就是if 函数起了作用，但是一时间不知道是为啥。。

经过多方面测试 concat("境内") concat_ws("","境内")没用，

concat_ws("",arrary("境内")) 有用，此时也不知道如何下手，只有掏出大杀器 explain.

起作用的

Plan optimized by CBO.
""
Vertex dependency in root stage
Map 1 <- Map 3 (BROADCAST_EDGE)
Reducer 2 <- Map 1 (SIMPLE_EDGE)
""
Stage-0
  Fetch Operator
    limit:-1
    Stage-1
      Reducer 2
      File Output Operator [FS_14]
        Select Operator [SEL_13] (rows=105 width=273)
"          Output:[""_col0"",""_col1"",""_col2"",""_col3"",""_col4"",""_col5"",""_col6"",""_col7""]"
          Group By Operator [GBY_12] (rows=105 width=273)
"            Output:[""_col0"",""_col1"",""_col2"",""_col3"",""_col4""],keys:KEY._col0, KEY._col1, KEY._col2, KEY._col3, KEY._col4"
          <-Map 1 [SIMPLE_EDGE] vectorized
            SHUFFLE [RS_28]
"              PartitionCols:_col0, _col1, _col2, _col3, _col4"
              Group By Operator [GBY_27] (rows=211 width=273)
"                Output:[""_col0"",""_col1"",""_col2"",""_col3"",""_col4""],keys:_col1, _col2, _col3, _col4, _col5"
                Map Join Operator [MAPJOIN_26] (rows=211 width=273)
"                  Conds:SEL_25._col0=RS_23._col0(Inner),Output:[""_col1"",""_col2"",""_col3"",""_col4"",""_col5""]"
                <-Map 3 [BROADCAST_EDGE] vectorized
                  BROADCAST [RS_23]
                    PartitionCols:_col0
                    Select Operator [SEL_22] (rows=1 width=736)
"                      Output:[""_col0"",""_col1"",""_col2"",""_col3""]"
                      Filter Operator [FIL_21] (rows=1 width=736)
                        predicate:bank_code is not null
                        TableScan [TS_3] (rows=1 width=736)
"                          dwapsdata@dw_conf_ce_bank_dict_v,t1,Tbl:COMPLETE,Col:NONE,Output:[""bank_code"",""bank_name"",""bank_short_name"",""bank_onshore_flag""]"
                <-Select Operator [SEL_25] (rows=192 width=273)
"                    Output:[""_col0"",""_col1""]"
                    Filter Operator [FIL_24] (rows=192 width=273)
                      predicate:bank_code is not null
                      TableScan [TS_0] (rows=192 width=273)
"                        dwdmdata@dm_ce_f_portrait_credit_line,t,Tbl:COMPLETE,Col:COMPLETE,Output:[""bank_code""]"
""

没有作用的

Plan optimized by CBO.
""
Vertex dependency in root stage
Map 1 <- Map 3 (BROADCAST_EDGE)
Reducer 2 <- Map 1 (SIMPLE_EDGE)
""
Stage-0
  Fetch Operator
    limit:-1
    Stage-1
      Reducer 2 vectorized
      File Output Operator [FS_31]
        Select Operator [SEL_30] (rows=105 width=273)
"          Output:[""_col0"",""_col1"",""_col2"",""_col3"",""_col4"",""_col5"",""_col6""]"
          Group By Operator [GBY_29] (rows=105 width=273)
"            Output:[""_col0"",""_col1"",""_col2"",""_col3"",""_col4""],keys:KEY._col0, KEY._col1, KEY._col2, KEY._col3, KEY._col4"
          <-Map 1 [SIMPLE_EDGE] vectorized
            SHUFFLE [RS_28]
"              PartitionCols:_col0, _col1, _col2, _col3, _col4"
              Group By Operator [GBY_27] (rows=211 width=273)
"                Output:[""_col0"",""_col1"",""_col2"",""_col3"",""_col4""],keys:_col1, _col2, _col3, _col4, _col5"
                Map Join Operator [MAPJOIN_26] (rows=211 width=273)
"                  Conds:SEL_25._col0=RS_23._col0(Inner),Output:[""_col1"",""_col2"",""_col3"",""_col4"",""_col5""]"
                <-Map 3 [BROADCAST_EDGE] vectorized
                  BROADCAST [RS_23]
                    PartitionCols:_col0
                    Select Operator [SEL_22] (rows=1 width=736)
"                      Output:[""_col0"",""_col1"",""_col2"",""_col3""]"
                      Filter Operator [FIL_21] (rows=1 width=736)
                        predicate:bank_code is not null
                        TableScan [TS_3] (rows=1 width=736)
"                          dwapsdata@dw_conf_ce_bank_dict_v,t1,Tbl:COMPLETE,Col:NONE,Output:[""bank_code"",""bank_name"",""bank_short_name"",""bank_onshore_flag""]"
                <-Select Operator [SEL_25] (rows=192 width=273)
"                    Output:[""_col0"",""_col1""]"
                    Filter Operator [FIL_24] (rows=192 width=273)
                      predicate:bank_code is not null
                      TableScan [TS_0] (rows=192 width=273)
"                        dwdmdata@dm_ce_f_portrait_credit_line,t,Tbl:COMPLETE,Col:COMPLETE,Output:[""bank_code""]"
""

对比发现

vectorzied 这个单词一出来我就知道怎么回事了。

hive decimal bug， nvl(decimal,1)=0_cclovezbf的博客-CSDN博客

这个b参数好处没体会到一点，bug到是一堆。

set hive.vectorized.execution.enabled=false; 即可解决中文乱码问题！！！！！！！

其实还有别的办法，但是和concat_ws(array(""))一样比较丑陋，我就不说了