hadoop - 如何在配置单元 0.13 中使用带空格的别名

Question

我正在使用 HDP 2.1 hortonwork，hive 0.13。我想在查询中使用带空格的别名，但出现错误，别名中是否可以有空格？ (没有空格别名也能正常工作)。尝试使用单引号，没有引号仍然失败。

*hive> select ot_vdot "alias test" from test4 where ot_vdot<>'null';
NoViableAltException(301@[146:1: selectExpression : ( expression | tableAllColumns );])
    at org.antlr.runtime.DFA.noViableAlt(DFA.java:158)
    at org.antlr.runtime.DFA.predict(DFA.java:144)
    at org.apache.hadoop.hive.ql.parse.HiveParser_SelectClauseParser.selectExpression(HiveParser_SelectClauseParser.java:4142)
    at org.apache.hadoop.hive.ql.parse.HiveParser_SelectClauseParser.selectItem(HiveParser_SelectClauseParser.java:3038)
    at org.apache.hadoop.hive.ql.parse.HiveParser_SelectClauseParser.selectList(HiveParser_SelectClauseParser.java:1307)
    at org.apache.hadoop.hive.ql.parse.HiveParser_SelectClauseParser.selectClause(HiveParser_SelectClauseParser.java:1070)
    at org.apache.hadoop.hive.ql.parse.HiveParser.selectClause(HiveParser.java:40193)
    at org.apache.hadoop.hive.ql.parse.HiveParser.singleSelectStatement(HiveParser.java:38048)
    at org.apache.hadoop.hive.ql.parse.HiveParser.selectStatement(HiveParser.java:37754)
    at org.apache.hadoop.hive.ql.parse.HiveParser.regularBody(HiveParser.java:37691)
    at org.apache.hadoop.hive.ql.parse.HiveParser.queryStatementExpressionBody(HiveParser.java:36898)
    at org.apache.hadoop.hive.ql.parse.HiveParser.queryStatementExpression(HiveParser.java:36774)
    at org.apache.hadoop.hive.ql.parse.HiveParser.execStatement(HiveParser.java:1338)
    at org.apache.hadoop.hive.ql.parse.HiveParser.statement(HiveParser.java:1036)
    at org.apache.hadoop.hive.ql.parse.ParseDriver.parse(ParseDriver.java:199)
    at org.apache.hadoop.hive.ql.parse.ParseDriver.parse(ParseDriver.java:166)
    at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:408)
    at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:322)
    at org.apache.hadoop.hive.ql.Driver.compileInternal(Driver.java:976)
    at org.apache.hadoop.hive.ql.Driver.runInternal(Driver.java:1041)
    at org.apache.hadoop.hive.ql.Driver.run(Driver.java:912)
    at org.apache.hadoop.hive.ql.Driver.run(Driver.java:902)
    at org.apache.hadoop.hive.cli.CliDriver.processLocalCmd(CliDriver.java:268)
    at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:220)
    at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:423)
    at org.apache.hadoop.hive.cli.CliDriver.executeDriver(CliDriver.java:793)
    at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:686)
    at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:625)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:212)
FAILED: ParseException line 1:15 cannot recognize input near 'ot_vdot' '"alias test"'  'from' in select expression
hive>
*

Answer 1

反引号是 hive 给事物命名的方式，带有奇怪的字符或保留字。例如:

select `my field with spaces`, `select`, `where` from `_my_table`