Fix null result in federated query for a single projected column (#32444

)
apache · Aug 12, 2024 · 57b084b · 57b084b
1 parent 4d448e5
commit 57b084b
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Showing 4 changed files with 21 additions and 5 deletions.
diff --git a/...c/main/java/org/apache/shardingsphere/sqlfederation/resultset/SQLFederationResultSet.java b/...c/main/java/org/apache/shardingsphere/sqlfederation/resultset/SQLFederationResultSet.java
@@ -105,7 +105,7 @@ public boolean next() {
         if (result && null != enumerator.current()) {
             currentRows = enumerator.current().getClass().isArray() && !(enumerator.current() instanceof byte[]) ? (Object[]) enumerator.current() : new Object[]{enumerator.current()};
         } else {
-            currentRows = new Object[]{};
+            currentRows = new Object[]{null};
         }
         return result;
     }

diff --git a/...g/apache/shardingsphere/sqlfederation/optimizer/function/mysql/impl/MySQLBinFunction.java b/...g/apache/shardingsphere/sqlfederation/optimizer/function/mysql/impl/MySQLBinFunction.java
@@ -42,14 +42,14 @@ public static String bin(final Object value) {
         if (value instanceof Number && !(value instanceof BigInteger)) {
             return Long.toBinaryString(((Number) value).longValue());
         }
+        if (value instanceof String && ((String) value).isEmpty()) {
+            return null;
+        }
         BigInteger bigIntegerValue = value instanceof BigInteger ? (BigInteger) value : new BigInteger(getFirstNumbers(String.valueOf(value)));
         return -1 == bigIntegerValue.signum() ? bigIntegerValue.add(BigInteger.ONE.shiftLeft(Long.SIZE).subtract(BigInteger.ONE)).add(BigInteger.ONE).toString(2) : bigIntegerValue.toString(2);
     }
 
     private static String getFirstNumbers(final String value) {
-        if (value.isEmpty()) {
-            return "0";
-        }
         boolean isNegative = '-' == value.charAt(0);
         StringBuilder result = new StringBuilder();
         if (isNegative) {

diff --git a/...che/shardingsphere/sqlfederation/optimizer/function/mysql/impl/MySQLBitCountFunction.java b/...che/shardingsphere/sqlfederation/optimizer/function/mysql/impl/MySQLBitCountFunction.java
@@ -39,7 +39,7 @@ public final class MySQLBitCountFunction {
     @SuppressWarnings("unused")
     public static Object bitCount(final Object value) {
         if (null == value) {
-            return 0;
+            return null;
         }
         if (value instanceof byte[]) {
             return bitCount((byte[]) value);

diff --git a/test/e2e/sql/src/test/resources/cases/dql/e2e-dql-select.xml b/test/e2e/sql/src/test/resources/cases/dql/e2e-dql-select.xml
@@ -306,6 +306,10 @@
         <assertion expected-data-source-name="read_dataset" />
     </test-case>
 
+    <test-case sql="SELECT BIT_COUNT(NULL)" db-types="MySQL" scenario-types="db_tbl_sql_federation">
+        <assertion expected-data-source-name="read_dataset" />
+    </test-case>
+
     <test-case sql="SELECT bit_count(123456), bit_count('123456'), bit_count('abcdefg'), BIT_COUNT('abcdef1234'), bit_count(''), bit_count(1 + 1)" db-types="MySQL" scenario-types="db_tbl_sql_federation">
         <assertion expected-data-source-name="read_dataset" />
     </test-case>
@@ -370,4 +374,16 @@
                     INNER JOIN t_order_item t3 ON t2.product_id = t3.product_id INNER JOIN t_order t4 ON t4.order_id = t3.order_id order by t1.product_id" db-types="MySQL" scenario-types="db_tbl_sql_federation">
         <assertion expected-data-source-name="read_dataset" />
     </test-case>
+
+    <test-case sql="SELECT BIN(NULL)" db-types="MySQL" scenario-types="db_tbl_sql_federation">
+        <assertion expected-data-source-name="read_dataset" />
+    </test-case>
+
+    <test-case sql="SELECT BIN('')" db-types="MySQL" scenario-types="db_tbl_sql_federation">
+        <assertion expected-data-source-name="read_dataset" />
+    </test-case>
+
+    <test-case sql="SELECT BIN(NULL), BIN(''), BIN(' ')" db-types="MySQL" scenario-types="db_tbl_sql_federation">
+        <assertion expected-data-source-name="read_dataset" />
+    </test-case>
 </e2e-test-cases>