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[FLINK-38247] Handle BIGINT UNSIGNED overflow in PreparedStatement #4117

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[FLINK-38247] Handle BIGINT UNSIGNED overflow in PreparedStatement #4117

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397daca
feat: handling bigint unsigned to BigDecimal
suhwan-cheon Sep 14, 2025
718ccf9
add: MySqlSourceITCase
suhwan-cheon Sep 18, 2025
547cd9b
add: mvn spotless
suhwan-cheon Sep 19, 2025
eb61a68
fix: checkstyle
suhwan-cheon Sep 20, 2025
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29 changes: 21 additions & 8 deletions ...-cdc/src/main/java/org/apache/flink/cdc/connectors/mysql/source/utils/StatementUtils.java
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@
import io.debezium.jdbc.JdbcConnection;
import io.debezium.relational.TableId;

import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
Expand Down Expand Up @@ -76,6 +77,18 @@ public static long queryApproximateRowCnt(JdbcConnection jdbc, TableId tableId)
});
}

// PreparedStatement#setObject method will be converted to long type when handling bigint unsigned, which poses a data overflow issue.
// Therefore, we need to handle the overflow issue by converting the long value to BigDecimal.
public static void setSafeObject(PreparedStatement ps, int parameterIndex, Object value)
throws SQLException {
if (value instanceof Long && (Long) value < 0L) {
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It should be BigInteger type, you can verify this in itcase.

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@lvyanquan lvyanquan Sep 15, 2025 •
edited
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Example of sql lists for possible test case:



CREATE TABLE `unsigned_bigint_pk`
--
(
`order_id`  BIGINT UNSIGNED NOT NULL,
`desc`  varchar(512) NOT NULL,
PRIMARY KEY (`order_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO unsigned_bigint_pk
VALUES (1,  'flink'),
(2,  'flink'),
(3,  'flink'),
(4,  'flink'),
(5,  'flink'),
(6,  'flink'),
(7,  'flink'),
(8,  'flink'),
(9,  'flink'),
(10,  'flink'),
(11,  'flink'),
(12,  'flink'),
(18446744073709551604,  'flink'),
(18446744073709551605,  'flink'),
(18446744073709551606,  'flink'),
(18446744073709551607,  'flink'),
(18446744073709551608,  'flink'),
(18446744073709551609,  'flink'),
(18446744073709551610,  'flink'),
(18446744073709551611,  'flink'),
(18446744073709551612,  'flink'),
(18446744073709551613,  'flink'),
(18446744073709551614,  'flink'),
(18446744073709551615,  'flink');

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@lvyanquan
Hello! I added itcase in MySqlSourceITCase.

I think JDBC may surface BIGINT UNSIGNED as Long (values > Long.MAX_VALUE appear negative due to two’s complement)
So In this code, 1) detect negative Longs 2) bind them as BigInteger, ensuring values near 2^64−1 are handled correctly.
I Added an IT in MySqlSourceITCase that creates unsigned_bigint_pk and verifies boundary values. And I saw that the test worked well.

ps.setBigDecimal(
parameterIndex, new BigDecimal(Long.toUnsignedString((Long) value)));
return;
}
ps.setObject(parameterIndex, value);
}

public static Object queryMin(
JdbcConnection jdbc, TableId tableId, String columnName, Object excludedLowerBound)
throws SQLException {
Expand All @@ -85,7 +98,7 @@ public static Object queryMin(
quote(columnName), quote(tableId), quote(columnName));
return jdbc.prepareQueryAndMap(
minQuery,
ps -> ps.setObject(1, excludedLowerBound),
ps -> setSafeObject(ps, 1, excludedLowerBound),
rs -> {
if (!rs.next()) {
// this should never happen
Expand Down Expand Up @@ -118,7 +131,7 @@ public static Object queryNextChunkMax(
chunkSize);
return jdbc.prepareQueryAndMap(
query,
ps -> ps.setObject(1, includedLowerBound),
ps -> setSafeObject(ps, 1, includedLowerBound),
rs -> {
if (!rs.next()) {
// this should never happen
Expand Down Expand Up @@ -204,18 +217,18 @@ public static PreparedStatement readTableSplitDataStatement(
}
if (isFirstSplit) {
for (int i = 0; i < primaryKeyNum; i++) {
statement.setObject(i + 1, splitEnd[i]);
statement.setObject(i + 1 + primaryKeyNum, splitEnd[i]);
setSafeObject(statement, i + 1, splitEnd[i]);
setSafeObject(statement, i + 1 + primaryKeyNum, splitEnd[i]);
}
} else if (isLastSplit) {
for (int i = 0; i < primaryKeyNum; i++) {
statement.setObject(i + 1, splitStart[i]);
setSafeObject(statement, i + 1, splitStart[i]);
}
} else {
for (int i = 0; i < primaryKeyNum; i++) {
statement.setObject(i + 1, splitStart[i]);
statement.setObject(i + 1 + primaryKeyNum, splitEnd[i]);
statement.setObject(i + 1 + 2 * primaryKeyNum, splitEnd[i]);
setSafeObject(statement, i + 1, splitStart[i]);
setSafeObject(statement, i + 1 + primaryKeyNum, splitEnd[i]);
setSafeObject(statement, i + 1 + 2 * primaryKeyNum, splitEnd[i]);
}
}
return statement;
Expand Down
106 changes: 106 additions & 0 deletions .../src/test/java/org/apache/flink/cdc/connectors/mysql/source/utils/StatementUtilsTest.java
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Original file line number Diff line number Diff line change
@@ -0,0 +1,106 @@
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package org.apache.flink.cdc.connectors.mysql.source.utils;

import org.junit.jupiter.api.Test;

import java.lang.reflect.Proxy;
import java.math.BigDecimal;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;

import static org.assertj.core.api.Assertions.assertThat;

/** Unit test for {@link org.apache.flink.cdc.connectors.mysql.source.utils.StatementUtils}. */
class StatementUtilsTest {

@Test
void testSetSafeObjectCorrectlyHandlesOverflow() throws SQLException {
Map<String, Object> invocationDetails = new HashMap<>();
PreparedStatement psProxy = createPreparedStatementProxy(invocationDetails);

long overflowValue = Long.MAX_VALUE + 1L;
BigDecimal expectedBigDecimal = new BigDecimal(Long.toUnsignedString(overflowValue));

// Use the safe method
StatementUtils.setSafeObject(psProxy, 1, overflowValue);

// Assert that it correctly used setBigDecimal with the converted value
assertThat(invocationDetails.get("methodName")).isEqualTo("setBigDecimal");
assertThat(invocationDetails.get("value")).isEqualTo(expectedBigDecimal);
}

@Test
void testDirectSetObjectFailsOnOverflow() throws SQLException {
Map<String, Object> invocationDetails = new HashMap<>();
PreparedStatement psProxy = createPreparedStatementProxy(invocationDetails);

long overflowValue = Long.MAX_VALUE + 1L;

// Directly call the unsafe method on the proxy
psProxy.setObject(1, overflowValue);

// Assert that it incorrectly used setObject, preserving the wrong negative long value
assertThat(invocationDetails.get("methodName")).isEqualTo("setObject");
assertThat(invocationDetails.get("value")).isInstanceOf(Long.class);
assertThat(invocationDetails.get("value")).isEqualTo(Long.MIN_VALUE);
}

@Test
void testSetSafeObjectHandlesRegularValues() throws SQLException {
Map<String, Object> invocationDetails = new HashMap<>();
PreparedStatement psProxy = createPreparedStatementProxy(invocationDetails);

// Test with a common Long
StatementUtils.setSafeObject(psProxy, 1, 123L);
assertThat(invocationDetails.get("methodName")).isEqualTo("setObject");
assertThat(invocationDetails.get("value")).isEqualTo(123L);
invocationDetails.clear();

// Test with a String
StatementUtils.setSafeObject(psProxy, 2, "test");
assertThat(invocationDetails.get("methodName")).isEqualTo("setObject");
assertThat(invocationDetails.get("value")).isEqualTo("test");
invocationDetails.clear();

// Test with null
StatementUtils.setSafeObject(psProxy, 3, null);
assertThat(invocationDetails.get("methodName")).isEqualTo("setObject");
assertThat(invocationDetails.get("value")).isNull();
invocationDetails.clear();
}

private PreparedStatement createPreparedStatementProxy(Map<String, Object> invocationDetails) {
return (PreparedStatement)
Proxy.newProxyInstance(
StatementUtilsTest.class.getClassLoader(),
new Class<?>[] {PreparedStatement.class},
(proxy, method, args) -> {
String methodName = method.getName();
if (methodName.equals("setObject")
|| methodName.equals("setBigDecimal")) {
invocationDetails.put("methodName", methodName);
invocationDetails.put("parameterIndex", args[0]);
invocationDetails.put("value", args[1]);
}
return null;
});
}
}