感谢大佬,我找到了。
所以说SQL类的内建函数实际上使用的是calcite的能力,而flink自己的内建函数是在table api中使用
> 2023年11月24日 17:07,Xuyang 写道:
>
> Hi,
> 关于你举的例子,如果编译了源码的话,可以在FlinkSqlParserImpl这个被动态生成的词法解析器类中找到PostfixRowOperator方法,大致是通过识别到IS
> NOT NULL这三个关键字,转化为Calcite的这个内置函数SqlStdOperatorTable.IS_NOT_NULL
>
>
>
>
> --
>
>Best!
>Xuyang
>
>
>
>
>
> 在 2023-11-24 15:15:04,"jinzhuguang" 写道:
>> flink 1.18.0
>>
>>
>> 例如我写下一条SQL:
>> select * from KafkaTable where id is not null;
>>
>> IS NOT NULL应该属于系统内建函数,于是我找到相关代码:
>>
>> public static final BuiltInFunctionDefinition IS_NOT_NULL =
>> BuiltInFunctionDefinition.newBuilder()
>> .name("isNotNull")
>> .kind(SCALAR)
>>
>> .inputTypeStrategy(wildcardWithCount(ConstantArgumentCount.of(1)))
>>
>> .outputTypeStrategy(explicit(DataTypes.BOOLEAN().notNull()))
>> .build();
>>
>> 发现他的name是“ isNotNull”,和“is not null”对应不上。并且经过实际测验,确实证实了我的猜想:
>>
>> DEBUG org.apache.flink.table.module.ModuleManager [] -
>> Cannot find FunctionDefinition 'is not null' from any loaded modules.
>>
>>
>> 所以我很疑惑,SQL到底是在哪里找到了”is not null”这个函数的呢?
>>
>> 以下是调用栈:
>> @org.apache.flink.table.planner.catalog.FunctionCatalogOperatorTable.lookupOperatorOverloads()
>> at
>> org.apache.calcite.sql.util.ChainedSqlOperatorTable.lookupOperatorOverloads(ChainedSqlOperatorTable.java:69)
>> at
>> org.apache.calcite.sql.SqlUtil.lookupSubjectRoutinesByName(SqlUtil.java:609)
>> at
>> org.apache.calcite.sql.SqlUtil.lookupSubjectRoutines(SqlUtil.java:535)
>> at org.apache.calcite.sql.SqlUtil.lookupRoutine(SqlUtil.java:486)
>> at org.apache.calcite.sql.SqlOperator.deriveType(SqlOperator.java:595)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl$DeriveTypeVisitor.visit(SqlValidatorImpl.java:6302)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl$DeriveTypeVisitor.visit(SqlValidatorImpl.java:6287)
>> at org.apache.calcite.sql.SqlCall.accept(SqlCall.java:161)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.deriveTypeImpl(SqlValidatorImpl.java:1869)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.deriveType(SqlValidatorImpl.java:1860)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.validateWhereOrOn(SqlValidatorImpl.java:4341)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.validateWhereClause(SqlValidatorImpl.java:4333)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.validateSelect(SqlValidatorImpl.java:3606)
>> at
>> org.apache.calcite.sql.validate.SelectNamespace.validateImpl(SelectNamespace.java:64)
>> at
>> org.apache.calcite.sql.validate.AbstractNamespace.validate(AbstractNamespace.java:89)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.validateNamespace(SqlValidatorImpl.java:1050)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.validateQuery(SqlValidatorImpl.java:1025)
>> at org.apache.calcite.sql.SqlSelect.validate(SqlSelect.java:248)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.validateScopedExpression(SqlValidatorImpl.java:1000)
>> at
>> org.apache.calcite.sql.validate.SqlValidatorImpl.validate(SqlValidatorImpl.java:749)
>> at
>> org.apache.flink.table.planner.calcite.FlinkPlannerImpl.org$apache$flink$table$planner$calcite$FlinkPlannerImpl$$validate(FlinkPlannerImpl.scala:196)
>> at
>> org.apache.flink.table.planner.calcite.FlinkPlannerImpl.validate(FlinkPlannerImpl.scala:117)
>> at
>> org.apache.flink.table.planner.operations.SqlNodeToOperationConversion.convert(SqlNodeToOperationConversion.java:261)
>> at
>> org.apache.flink.table.planner.delegation.ParserImpl.parse(ParserImpl.java:106)
>> at
>> org.apache.flink.table.gateway.service.operation.OperationExecutor.executeStatement(OperationExecutor.java:187)
>> at
>> org.apache.flink.table.gateway.service.SqlGatewayServiceImpl.lambda$executeStatement$1(SqlGatewayServiceImpl.java:212)
>> at
>> org.apache.flink.table.gateway.service.operation.OperationManager.lambda$submitOperation$1(OperationManager.java:119)
>> at
>> org.apache.flink.table.gateway.service.operation.OperationManager$Operation.lambda$run$0(OperationManager.java:258)
>> at
>> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
>> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
>> at
>> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
>> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
>> at
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
>> at
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
>> at java.lang.Thread.run(Thread.java:750)