org.apache.flink.table.planner.functions.aggfunctions.SumAggFunction Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.flink.table.planner.functions.aggfunctions;
import org.apache.flink.table.api.DataTypes;
import org.apache.flink.table.api.TableException;
import org.apache.flink.table.expressions.Expression;
import org.apache.flink.table.expressions.UnresolvedReferenceExpression;
import org.apache.flink.table.types.DataType;
import org.apache.flink.table.types.logical.DecimalType;
import org.apache.flink.table.types.logical.utils.LogicalTypeMerging;
import static org.apache.flink.table.expressions.ApiExpressionUtils.unresolvedRef;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.ifThenElse;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.isNull;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.nullOf;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.plus;
/** built-in sum aggregate function. */
public abstract class SumAggFunction extends DeclarativeAggregateFunction {
private UnresolvedReferenceExpression sum = unresolvedRef("sum");
@Override
public int operandCount() {
return 1;
}
@Override
public UnresolvedReferenceExpression[] aggBufferAttributes() {
return new UnresolvedReferenceExpression[] {sum};
}
@Override
public DataType[] getAggBufferTypes() {
return new DataType[] {getResultType()};
}
@Override
public Expression[] initialValuesExpressions() {
return new Expression[] {/* sum = */ nullOf(getResultType())};
}
@Override
public Expression[] accumulateExpressions() {
return new Expression[] {
/* sum = */ ifThenElse(
isNull(operand(0)),
sum,
ifThenElse(isNull(sum), operand(0), plus(sum, operand(0))))
};
}
@Override
public Expression[] retractExpressions() {
throw new TableException(
"This function does not support retraction, Please choose SumWithRetractAggFunction.");
}
@Override
public Expression[] mergeExpressions() {
return new Expression[] {
/* sum = */ ifThenElse(
isNull(mergeOperand(sum)),
sum,
ifThenElse(isNull(sum), mergeOperand(sum), plus(sum, mergeOperand(sum))))
};
}
@Override
public Expression getValueExpression() {
return sum;
}
/** Built-in Int Sum aggregate function. */
public static class IntSumAggFunction extends SumAggFunction {
@Override
public DataType getResultType() {
return DataTypes.INT();
}
}
/** Built-in Byte Sum aggregate function. */
public static class ByteSumAggFunction extends SumAggFunction {
@Override
public DataType getResultType() {
return DataTypes.TINYINT();
}
}
/** Built-in Short Sum aggregate function. */
public static class ShortSumAggFunction extends SumAggFunction {
@Override
public DataType getResultType() {
return DataTypes.SMALLINT();
}
}
/** Built-in Long Sum aggregate function. */
public static class LongSumAggFunction extends SumAggFunction {
@Override
public DataType getResultType() {
return DataTypes.BIGINT();
}
}
/** Built-in Float Sum aggregate function. */
public static class FloatSumAggFunction extends SumAggFunction {
@Override
public DataType getResultType() {
return DataTypes.FLOAT();
}
}
/** Built-in Double Sum aggregate function. */
public static class DoubleSumAggFunction extends SumAggFunction {
@Override
public DataType getResultType() {
return DataTypes.DOUBLE();
}
}
/** Built-in Decimal Sum aggregate function. */
public static class DecimalSumAggFunction extends SumAggFunction {
private DecimalType decimalType;
public DecimalSumAggFunction(DecimalType decimalType) {
this.decimalType = decimalType;
}
@Override
public DataType getResultType() {
DecimalType sumType = (DecimalType) LogicalTypeMerging.findSumAggType(decimalType);
return DataTypes.DECIMAL(sumType.getPrecision(), sumType.getScale());
}
}
}