Examples with UnresolvedWatermarkSpec org.apache.flink.table.api.Schema.UnresolvedWatermarkSpec used on opensource projects

Example 1 with UnresolvedWatermarkSpec

use of org.apache.flink.table.api.Schema.UnresolvedWatermarkSpec in project flink by apache.

the class DefaultSchemaResolver method resolveWatermarkSpecs.

private List<WatermarkSpec> resolveWatermarkSpecs(List<UnresolvedWatermarkSpec> unresolvedWatermarkSpecs, List<Column> inputColumns) {
    if (unresolvedWatermarkSpecs.size() == 0) {
        return Collections.emptyList();
    }
    if (unresolvedWatermarkSpecs.size() > 1) {
        throw new ValidationException("Multiple watermark definitions are not supported yet.");
    }
    final UnresolvedWatermarkSpec watermarkSpec = unresolvedWatermarkSpecs.get(0);
    // validate time attribute
    final String timeColumn = watermarkSpec.getColumnName();
    final Column validatedTimeColumn = validateTimeColumn(timeColumn, inputColumns);
    // resolve watermark expression
    final ResolvedExpression watermarkExpression;
    try {
        watermarkExpression = resolveExpression(inputColumns, watermarkSpec.getWatermarkExpression(), validatedTimeColumn.getDataType());
    } catch (Exception e) {
        throw new ValidationException(String.format("Invalid expression for watermark '%s'.", watermarkSpec.toString()), e);
    }
    final LogicalType outputType = watermarkExpression.getOutputDataType().getLogicalType();
    final LogicalType timeColumnType = validatedTimeColumn.getDataType().getLogicalType();
    validateWatermarkExpression(outputType);
    if (outputType.getTypeRoot() != timeColumnType.getTypeRoot()) {
        throw new ValidationException(String.format("The watermark declaration's output data type '%s' is different " + "from the time field's data type '%s'.", outputType, timeColumnType));
    }
    return Collections.singletonList(WatermarkSpec.of(watermarkSpec.getColumnName(), watermarkExpression));
}