diff --git a/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/SqlMutationSession.java b/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/SqlMutationSession.java
index ff6005535..f356b1161 100644
--- a/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/SqlMutationSession.java
+++ b/xtraplatform-features-sql/src/main/java/de/ii/xtraplatform/features/sql/app/SqlMutationSession.java
@@ -509,8 +509,11 @@ public FeatureTransactions.MutationResult assertNoConflictingVersion(
     return builder.build();
   }
 
-  // Batch variant of the versioned-Insert pre-flight: one SELECT on the main table for all ids, the
-  // ids found are returned in `ids`.
+  // Batch variant of the versioned-Insert pre-flight: one query for all ids, the ids of which a
+  // version exists are returned in `ids`, as they were given. Each id is checked for existence as
+  // in the single-id check and the query returns the given literal, not the column value: the text
+  // form of the column value can differ from the given id, e.g. 7 for '007' in an integer column, a
+  // UUID in lower case or a char(n) value with padding.
   @Override
   public FeatureTransactions.MutationResult findConflictingVersions(
       String featureType, Collection<String> featureIds) {
@@ -533,20 +536,26 @@ public FeatureTransactions.MutationResult findConflictingVersions(
                       + "' has no id column; cannot run the versioned-insert pre-flight."))
           .build();
     }
+    String mainTableName = idColumn.get().first().getName();
     String idCol = idColumn.get().second().getName();
     String sql =
-        "SELECT DISTINCT "
-            + idCol
-            + SQL_FROM
-            + idColumn.get().first().getName()
-            + SQL_WHERE
-            + idCol
-            + " IN ("
-            + featureIds.stream()
+        featureIds.stream()
                 .distinct()
                 .map(SqlMutationSession::sqlString)
-                .collect(Collectors.joining(", "))
-            + ");";
+                .map(
+                    id ->
+                        SQL_SELECT
+                            + id
+                            + " WHERE EXISTS (SELECT 1"
+                            + SQL_FROM
+                            + mainTableName
+                            + SQL_WHERE
+                            + idCol
+                            + SQL_EQ
+                            + id
+                            + ")")
+                .collect(Collectors.joining(" UNION ALL "))
+            + ";";
     try {
       builder.ids(sqlSession.runReturning(sql));
     } catch (RuntimeException e) {
diff --git a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/VersionedMutationSqlSpec.groovy b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/VersionedMutationSqlSpec.groovy
index b9c8779f3..e9e6fab05 100644
--- a/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/VersionedMutationSqlSpec.groovy
+++ b/xtraplatform-features-sql/src/test/groovy/de/ii/xtraplatform/features/sql/app/VersionedMutationSqlSpec.groovy
@@ -76,20 +76,53 @@ class VersionedMutationSqlSpec extends Specification {
         }) >> []
     }
 
-    def 'Insert pre-flight for a batch: findConflictingVersions checks all ids with one SELECT'() {
+    def 'Insert pre-flight for a batch: findConflictingVersions checks all ids with one query'() {
         when:
         FeatureTransactions.MutationResult result = session.findConflictingVersions(
                 FEATURE_TYPE, ['DEABCDEF12345678', 'DEABCDEF00000001', 'DEABCDEF12345678'])
 
         then:
         1 * sqlSession.runReturning({ String sql ->
-            sql == "SELECT DISTINCT ${COL_ID} FROM ${TABLE} WHERE ${COL_ID} IN " +
-                    "('DEABCDEF12345678', 'DEABCDEF00000001');"
+            sql == "SELECT 'DEABCDEF12345678' WHERE EXISTS " +
+                    "(SELECT 1 FROM ${TABLE} WHERE ${COL_ID} = 'DEABCDEF12345678')" +
+                    " UNION ALL SELECT 'DEABCDEF00000001' WHERE EXISTS " +
+                    "(SELECT 1 FROM ${TABLE} WHERE ${COL_ID} = 'DEABCDEF00000001');"
         }) >> ['DEABCDEF12345678']
         result.ids == ['DEABCDEF12345678']
         result.error.isEmpty()
     }
 
+    def 'Insert pre-flight for a batch: an id is found also in another text form of the database: #given'() {
+        when:
+        FeatureTransactions.MutationResult result = session.findConflictingVersions(FEATURE_TYPE, given)
+
+        then:
+        1 * sqlSession.runReturning(_) >> { String sql -> integerColumnWithSeven(sql) }
+        result.ids as Set == found as Set
+
+        where:
+        given          | found
+        ['007', '8']   | ['007']
+        ['7', '007']   | ['7', '007']
+        ['8']          | []
+    }
+
+    /**
+     * Answers the query as PostgreSQL does for an integer id column with the row 7: a literal is
+     * compared as a number, the column value is returned as '7'.
+     */
+    private static List<String> integerColumnWithSeven(String sql) {
+        def isSeven = { String literal -> literal.isInteger() && literal.toInteger() == 7 }
+        def inList = sql =~ /^SELECT DISTINCT \w+ FROM \w+ WHERE \w+ IN \((.*)\);$/
+        if (inList.matches()) {
+            def literals = (inList.group(1) =~ /'([^']*)'/).collect { it[1] }
+            return literals.any(isSeven) ? ['7'] : []
+        }
+        return (sql =~ /SELECT '([^']*)' WHERE EXISTS \(SELECT 1 FROM \w+ WHERE \w+ = '([^']*)'\)/)
+                .findAll { isSeven(it[2]) }
+                .collect { it[1] }
+    }
+
     def 'Insert pre-flight for a batch: no ids, no query'() {
         when:
         FeatureTransactions.MutationResult result = session.findConflictingVersions(FEATURE_TYPE, [])
diff --git a/xtraplatform-features/src/main/java/de/ii/xtraplatform/features/domain/FeatureTransactions.java b/xtraplatform-features/src/main/java/de/ii/xtraplatform/features/domain/FeatureTransactions.java
index 612ea31b2..a07a4d19c 100644
--- a/xtraplatform-features/src/main/java/de/ii/xtraplatform/features/domain/FeatureTransactions.java
+++ b/xtraplatform-features/src/main/java/de/ii/xtraplatform/features/domain/FeatureTransactions.java
@@ -212,9 +212,11 @@ default MutationResult assertNoConflictingVersion(String featureType, String fea
 
     /**
      * Batch variant of {@link #assertNoConflictingVersion(String, String)}: returns in {@code ids}
-     * those of the {@code featureIds} of which a version already exists (open or retired), with one
-     * query instead of one per id. {@code error} is set when the check itself fails. The default
-     * implementation returns no ids (no check) for providers that have not adopted the API.
+     * those of the {@code featureIds} of which a version already exists (open or retired), as they
+     * were given, also when the stored id has another text form (e.g. {@code 7} for {@code 007} in
+     * an integer column), with one query instead of one per id. {@code error} is set when the check
+     * itself fails. The default implementation returns no ids (no check) for providers that have
+     * not adopted the API.
      */
     default MutationResult findConflictingVersions(
         String featureType, Collection<String> featureIds) {