feat: EXPOSED-729 [Oracle] Allow setting limit with DELETE

It is currently only possibe to set a limit on update() even though the same ROWNUM syntax that is used for that function provider also applies to delete(). This logic has now been shared across both and tests adjusted.
JetBrains · Feb 11, 2025 · d9c2983 · d9c2983
1 parent a32e1f6
commit d9c2983
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Showing 2 changed files with 11 additions and 9 deletions.
diff --git a/exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/vendors/OracleDialect.kt b/exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/vendors/OracleDialect.kt
@@ -241,11 +241,7 @@ internal object OracleFunctionProvider : FunctionProvider() {
         transaction: Transaction
     ): String {
         val def = super.update(target, columnsAndValues, null, where, transaction)
-        return when {
-            limit != null && where != null -> "$def AND ROWNUM <= $limit"
-            limit != null -> "$def WHERE ROWNUM <= $limit"
-            else -> def
-        }
+        return def.appendLimitClause(limit, endsWithWhere = where != null)
     }
 
     override fun update(
@@ -318,10 +314,16 @@ internal object OracleFunctionProvider : FunctionProvider() {
         limit: Int?,
         transaction: Transaction
     ): String {
-        if (limit != null) {
-            transaction.throwUnsupportedException("Oracle doesn't support LIMIT in DELETE clause.")
+        val def = super.delete(ignore, table, where, null, transaction)
+        return def.appendLimitClause(limit, endsWithWhere = where != null)
+    }
+
+    private fun String.appendLimitClause(limit: Int?, endsWithWhere: Boolean): String {
+        return when {
+            limit != null && endsWithWhere -> "$this AND ROWNUM <= $limit"
+            limit != null -> "$this WHERE ROWNUM <= $limit"
+            else -> this
         }
-        return super.delete(ignore, table, where, null, transaction)
     }
 
     override fun delete(

diff --git a/exposed-tests/src/test/kotlin/org/jetbrains/exposed/sql/tests/shared/dml/DeleteTests.kt b/exposed-tests/src/test/kotlin/org/jetbrains/exposed/sql/tests/shared/dml/DeleteTests.kt
@@ -22,7 +22,7 @@ import kotlin.test.expect
 class DeleteTests : DatabaseTestsBase() {
     private val limitNotSupported by lazy {
         val extra = setOf(TestDB.SQLITE).takeUnless { SQLiteDialect.ENABLE_UPDATE_DELETE_LIMIT }.orEmpty()
-        TestDB.ALL_POSTGRES_LIKE + TestDB.ALL_ORACLE_LIKE + extra
+        TestDB.ALL_POSTGRES_LIKE + extra
     }
 
     @Test