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【flink sql】flink sql insert into插入语句的问题

测试Flink版本:1.11.0

Flink sql支持这种语法插入吗,在插入时指定具体的字段顺序和要插入的列

Insert into tableName(col1[,col2]) select col1[,col2]

目前通过测试发现了以下问题

建表语句:

create table t1(a int,b string,c int) with ();

create table t2(a int,b string,c int) with ();

问题1:测试发现insert into时查询和sink schema的匹配规则是按照定义的顺序进行

测试语句:

insert into t2 select t1.a,t1.c, t1.b from t1;

报错信息:

org.apache.flink.table.api.ValidationException: Field types of query result and registered TableSink default_catalog.default_database.t2 do not match.

Query schema: [a: INT, c: INT, b: VARCHAR(2147483647)]

Sink schema: [a: INT, b: VARCHAR(2147483647), c: INT]

at org.apache.flink.table.planner.sinks.TableSinkUtils$.validateSchemaAndApplyI mplicitCast(TableSinkUtils.scala:100)

at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$2.apply(Plann erBase.scala:213)

at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$2.apply(Plann erBase.scala:204)

at scala.Option.map(Option.scala:146)

at org.apache.flink.table.planner.delegation.PlannerBase.translateToRel(Planner Base.scala:204)

at org.apache.flink.table.planner.delegation.StreamPlanner$$anonfun$1.apply(Str eamPlanner.scala:98)

at org.apache.flink.table.planner.delegation.StreamPlanner$$anonfun$1.apply(Str eamPlanner.scala:80)

at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala: 234)

at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala: 234)

at scala.collection.Iterator$class.foreach(Iterator.scala:891)

at scala.collection.AbstractIterator.foreach(Iterator.scala:1334)

at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)

at scala.collection.AbstractIterable.foreach(Iterable.scala:54)

at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)

at scala.collection.AbstractTraversable.map(Traversable.scala:104)

at org.apache.flink.table.planner.delegation.StreamPlanner.explain(StreamPlanne r.scala:80)

at org.apache.flink.table.planner.delegation.StreamPlanner.explain(StreamPlanne r.scala:43)

at org.apache.flink.table.api.internal.TableEnvironmentImpl.explain(TableEnviro nmentImpl.java:632)

问题2:支持Insert into tableName(col1[,col2]) select col1[,col2]的语法,但并 没有真正起作用,还是按照定义的顺序进行匹配

测试语句:

insert into t2(a,c,b) select t1.a,t1.c, t1.b from t1;

报错信息:

org.apache.flink.table.api.ValidationException: Field types of query result and registered TableSink default_catalog.default_database.t2 do not match.

Query schema: [a: INT, c: INT, b: VARCHAR(2147483647)]

Sink schema: [a: INT, b: VARCHAR(2147483647), c: INT]

at org.apache.flink.table.planner.sinks.TableSinkUtils$.validateSchemaAndApplyI mplicitCast(TableSinkUtils.scala:100)

at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$2.apply(Plann erBase.scala:213)

at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$2.apply(Plann erBase.scala:204)

at scala.Option.map(Option.scala:146)

at org.apache.flink.table.planner.delegation.PlannerBase.translateToRel(Planner Base.scala:204)

at org.apache.flink.table.planner.delegation.StreamPlanner$$anonfun$1.apply(Str eamPlanner.scala:98)

at org.apache.flink.table.planner.delegation.StreamPlanner$$anonfun$1.apply(Str eamPlanner.scala:80)

at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala: 234)

at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala: 234)

at scala.collection.Iterator$class.foreach(Iterator.scala:891)

at scala.collection.AbstractIterator.foreach(Iterator.scala:1334)

at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)

at scala.collection.AbstractIterable.foreach(Iterable.scala:54)

at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)

at scala.collection.AbstractTraversable.map(Traversable.scala:104)

at org.apache.flink.table.planner.delegation.StreamPlanner.explain(StreamPlanne r.scala:80)

at org.apache.flink.table.planner.delegation.StreamPlanner.explain(StreamPlanne r.scala:43)

at org.apache.flink.table.api.internal.TableEnvironmentImpl.explain(TableEnviro nmentImpl.java:632)

问题3:当insert into的字段比sink的schema的字段少也会如此

测试语句:

insert into t2(a,b)

select t1.a, t1.b from t1;

报错信息:

org.apache.flink.table.api.ValidationException: Field types of query result and registered TableSink default_catalog.default_database.t2 do not match.

Query schema: [a: INT, c: VARCHAR(2147483647)]

Sink schema: [a: INT, b: VARCHAR(2147483647), c: INT]

at org.apache.flink.table.planner.sinks.TableSinkUtils$.validateSchemaAndApplyI mplicitCast(TableSinkUtils.scala:100)

at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$2.apply(Plann erBase.scala:213)

at org.apache.flink.table.planner.delegation.PlannerBase$$anonfun$2.apply(Plann erBase.scala:204)

at scala.Option.map(Option.scala:146)

at org.apache.flink.table.planner.delegation.PlannerBase.translateToRel(Planner Base.scala:204)

at org.apache.flink.table.planner.delegation.StreamPlanner$$anonfun$1.apply(Str eamPlanner.scala:98)

at org.apache.flink.table.planner.delegation.StreamPlanner$$anonfun$1.apply(Str eamPlanner.scala:80)

at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala: 234)

at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala: 234)

at scala.collection.Iterator$class.foreach(Iterator.scala:891)

at scala.collection.AbstractIterator.foreach(Iterator.scala:1334)

at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)

at scala.collection.AbstractIterable.foreach(Iterable.scala:54)

at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)

at scala.collection.AbstractTraversable.map(Traversable.scala:104)

at org.apache.flink.table.planner.delegation.StreamPlanner.explain(StreamPlanne r.scala:80)

at org.apache.flink.table.planner.delegation.StreamPlanner.explain(StreamPlanne r.scala:43)

at org.apache.flink.table.api.internal.TableEnvironmentImp总结:

目前的实现限制了查询的和写人的灵活性,

只有找到schema定义的字段顺序才能进行正确的插入,

当字段很多时会比较麻烦,

还有,只插入某些列的需求也是存在的,目前不能支持*来自志愿者整理的flink邮件归档

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说了是一只鲳鱼 2021-12-07 10:10:44 1485 0
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  • Flink 目前的确不支持这个语法... 我已经创建了一个 issue[1],可以在那里跟踪这个 feature 的进展。

    [1] https://issues.apache.org/jira/browse/FLINK-18726*来自志愿者整理的flink邮件归档

    2021-12-07 11:37:54
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