private def validate()

in flink-table/flink-table-planner/src/main/scala/org/apache/flink/table/planner/calcite/FlinkPlannerImpl.scala [120:206]
83 lines of code
49 McCabe index (conditional complexity)

  private def validate(sqlNode: SqlNode, validator: FlinkCalciteSqlValidator): SqlNode = {
    try {
      sqlNode.accept(new PreValidateReWriter(validator, typeFactory))
      // do extended validation.
      sqlNode match {
        case node: ExtendedSqlNode =>
          node.validate()
        case _ =>
      }
      // no need to validate row type for DDL and insert nodes.
      if (
        sqlNode.getKind.belongsTo(SqlKind.DDL)
        || sqlNode.getKind == SqlKind.CREATE_FUNCTION
        || sqlNode.getKind == SqlKind.DROP_FUNCTION
        || sqlNode.getKind == SqlKind.OTHER_DDL
        || sqlNode.isInstanceOf[SqlLoadModule]
        || sqlNode.isInstanceOf[SqlShowCatalogs]
        || sqlNode.isInstanceOf[SqlShowCurrentCatalog]
        || sqlNode.isInstanceOf[SqlShowDatabases]
        || sqlNode.isInstanceOf[SqlShowCurrentDatabase]
        || sqlNode.isInstanceOf[SqlShowTables]
        || sqlNode.isInstanceOf[SqlShowModels]
        || sqlNode.isInstanceOf[SqlShowFunctions]
        || sqlNode.isInstanceOf[SqlShowJars]
        || sqlNode.isInstanceOf[SqlShowModules]
        || sqlNode.isInstanceOf[SqlShowViews]
        || sqlNode.isInstanceOf[SqlShowColumns]
        || sqlNode.isInstanceOf[SqlShowPartitions]
        || sqlNode.isInstanceOf[SqlShowProcedures]
        || sqlNode.isInstanceOf[SqlShowJobs]
        || sqlNode.isInstanceOf[SqlDescribeJob]
        || sqlNode.isInstanceOf[SqlRichDescribeFunction]
        || sqlNode.isInstanceOf[SqlRichDescribeModel]
        || sqlNode.isInstanceOf[SqlRichDescribeTable]
        || sqlNode.isInstanceOf[SqlUnloadModule]
        || sqlNode.isInstanceOf[SqlUseModules]
        || sqlNode.isInstanceOf[SqlBeginStatementSet]
        || sqlNode.isInstanceOf[SqlEndStatementSet]
        || sqlNode.isInstanceOf[SqlSet]
        || sqlNode.isInstanceOf[SqlReset]
        || sqlNode.isInstanceOf[SqlExecutePlan]
        || sqlNode.isInstanceOf[SqlTruncateTable]
      ) {
        return sqlNode
      }
      sqlNode match {
        case richExplain: SqlRichExplain =>
          val validatedStatement = richExplain.getStatement match {
            // only validate source here
            case insert: RichSqlInsert =>
              validateRichSqlInsert(insert)
            case others =>
              validate(others)
          }
          richExplain.setOperand(0, validatedStatement)
          richExplain
        case statementSet: SqlStatementSet =>
          statementSet.getInserts.asScala.zipWithIndex.foreach {
            case (insert, idx) => statementSet.setOperand(idx, validate(insert))
          }
          statementSet
        case execute: SqlExecute =>
          execute.setOperand(0, validate(execute.getStatement))
          execute
        case insert: RichSqlInsert =>
          validateRichSqlInsert(insert)
        case compile: SqlCompilePlan =>
          compile.setOperand(0, validate(compile.getOperandList.get(0)))
          compile
        case compileAndExecute: SqlCompileAndExecutePlan =>
          compileAndExecute.setOperand(0, validate(compileAndExecute.getOperandList.get(0)))
          compileAndExecute
        // for call procedure statement
        case sqlCallNode if sqlCallNode.getKind == SqlKind.PROCEDURE_CALL =>
          val callNode = sqlCallNode.asInstanceOf[SqlBasicCall]
          callNode.getOperandList.asScala.zipWithIndex.foreach {
            case (operand, idx) => callNode.setOperand(idx, validate(operand))
          }
          callNode
        case _ =>
          validator.validate(sqlNode)
      }
    } catch {
      case e: RuntimeException =>
        throw new ValidationException(s"SQL validation failed. ${e.getMessage}", e)
    }
  }