HHH-18142 Add Oracle Database 23ai support for DROP SEQUENCE IF EXISTS

hibernate · May 21, 2024 · fcc33f3 · fcc33f3
1 parent 31e3be1
commit fcc33f3
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Showing 3 changed files with 28 additions and 4 deletions.
diff --git a/...community-dialects/src/main/java/org/hibernate/community/dialect/OracleLegacyDialect.java b/...community-dialects/src/main/java/org/hibernate/community/dialect/OracleLegacyDialect.java
@@ -993,7 +993,7 @@ public boolean dropConstraints() {
 
 	@Override
 	public SequenceSupport getSequenceSupport() {
-		return OracleSequenceSupport.INSTANCE;
+		return OracleSequenceSupport.getInstance(this);
 	}
 
 	@Override

diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/OracleDialect.java b/hibernate-core/src/main/java/org/hibernate/dialect/OracleDialect.java
@@ -1048,7 +1048,7 @@ public boolean supportsAlterColumnType() {
 
 	@Override
 	public SequenceSupport getSequenceSupport() {
-		return OracleSequenceSupport.INSTANCE;
+		return OracleSequenceSupport.getInstance(this);
 	}
 
 	@Override

diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/sequence/OracleSequenceSupport.java b/hibernate-core/src/main/java/org/hibernate/dialect/sequence/OracleSequenceSupport.java
@@ -6,22 +6,46 @@
  */
 package org.hibernate.dialect.sequence;
 
+import org.hibernate.MappingException;
+import org.hibernate.dialect.Dialect;
+
 /**
  * Sequence support for {@link org.hibernate.dialect.OracleDialect}.
  *
  * @author Gavin King
+ * @author Loïc Lefèvre
+ *
+ * @see <a href="https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/CREATE-SEQUENCE.html">Oracle Database Documentation</a>
  */
 public final class OracleSequenceSupport extends NextvalSequenceSupport {
 
-	public static final SequenceSupport INSTANCE = new OracleSequenceSupport();
+	public static SequenceSupport getInstance(final Dialect dialect) {
+		return new OracleSequenceSupport(dialect);
+	}
+
+	private final boolean requiresFromDUAL;
+	private final boolean supportsIfExists;
+
+	// TODO: HHH-18144 - Support Oracle sequence optional KEEP for Application Continuity
+	// TODO: HHH-18143 - Support Oracle scalable sequences for RAC
+
+	public OracleSequenceSupport(final Dialect dialect) {
+		requiresFromDUAL = dialect.getVersion().isBefore(23);
+		supportsIfExists = dialect.getVersion().isSameOrAfter(23);
+	}
 
 	@Override
 	public String getFromDual() {
-		return " from dual";
+		return requiresFromDUAL ? " from dual" : "";
 	}
 
 	@Override
 	public boolean sometimesNeedsStartingValue() {
 		return true;
 	}
+
+	@Override
+	public String getDropSequenceString(String sequenceName) throws MappingException {
+		return "drop sequence " + (supportsIfExists ? "if exists " : "") + sequenceName;
+	}
 }