feat: Oracle hierarchical queries to except Expression in the operator

- fixes #2300

Signed-off-by: Andreas Reichel <[email protected]>

Author: manticore-projects

src/main/java/net/sf/jsqlparser/expression/ConnectByPriorOperator.java

@@ -35,15 +35,26 @@
  * @author are
  */
 public class ConnectByPriorOperator extends ASTNodeAccessImpl implements Expression {
-    private final Column column;
+    private final Expression expression;
 
+    @Deprecated
     public ConnectByPriorOperator(Column column) {
-        this.column = Objects.requireNonNull(column,
+        this.expression = Objects.requireNonNull(column,
                 "The COLUMN of the ConnectByPrior Operator must not be null");
     }
 
-    public Column getColumn() {
-        return column;
+    public ConnectByPriorOperator(Expression column) {
+        this.expression = Objects.requireNonNull(column,
+                "The COLUMN of the ConnectByPrior Operator must not be null");
+    }
+
+    @Deprecated
+    public Expression getColumn() {
+        return getExpression();
+    }
+
+    public Expression getExpression() {
+        return expression;
     }
 
     @Override
@@ -52,12 +63,12 @@ public <T, S> T accept(ExpressionVisitor<T> expressionVisitor, S context) {
     }
 
     public StringBuilder appendTo(StringBuilder builder) {
-        builder.append("PRIOR ").append(column);
+        builder.append("PRIOR ").append(expression);
         return builder;
     }
 
     @Override
     public String toString() {
         return appendTo(new StringBuilder()).toString();
     }
-}
+}

src/main/java/net/sf/jsqlparser/expression/ConnectByRootOperator.java

@@ -34,15 +34,26 @@
  * @author are
  */
 public class ConnectByRootOperator extends ASTNodeAccessImpl implements Expression {
-    private final Column column;
+    private final Expression expression;
 
+    @Deprecated
     public ConnectByRootOperator(Column column) {
-        this.column = Objects.requireNonNull(column,
+        this.expression = Objects.requireNonNull(column,
                 "The COLUMN of the ConnectByRoot Operator must not be null");
     }
 
-    public Column getColumn() {
-        return column;
+    public ConnectByRootOperator(Expression column) {
+        this.expression = Objects.requireNonNull(column,
+                "The EXPRESSION of the ConnectByRoot Operator must not be null");
+    }
+
+    @Deprecated
+    public Expression getColumn() {
+        return expression;
+    }
+
+    public Expression getExpression() {
+        return expression;
     }
 
     @Override
@@ -51,7 +62,7 @@ public <T, S> T accept(ExpressionVisitor<T> expressionVisitor, S context) {
     }
 
     public StringBuilder appendTo(StringBuilder builder) {
-        builder.append("CONNECT_BY_ROOT ").append(column);
+        builder.append("CONNECT_BY_ROOT ").append(expression);
         return builder;
     }
 

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -6545,23 +6545,30 @@ Expression PrimaryExpression() #PrimaryExpression:
     }
 }
 
+/* https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/img_text/hierarchical_query_clause.html
+
+    { CONNECT BY [ NOCYCLE ] condition [ START WITH condition ]
+    | START WITH condition CONNECT BY [ NOCYCLE ] condition
+    }
+ */
+
 ConnectByRootOperator ConnectByRootOperator() #ConnectByRootOperator: {
-    Column column;
+    Expression expression;
 }
 {
-    <K_CONNECT_BY_ROOT> column = Column()
+    <K_CONNECT_BY_ROOT> expression = Expression()
     {
-      return new ConnectByRootOperator(column);
+      return new ConnectByRootOperator(expression);
     }
 }
 
 ConnectByPriorOperator ConnectByPriorOperator() #ConnectByPriorOperator: {
-    Column column;
+    Expression expression;
 }
 {
-    <K_PRIOR> column = Column()
+    <K_PRIOR> expression = Expression()
     {
-      return new ConnectByPriorOperator(column);
+      return new ConnectByPriorOperator(expression);
     }
 }
 

src/test/java/net/sf/jsqlparser/expression/ConnectByRootOperatorTest.java

@@ -0,0 +1,23 @@
+package net.sf.jsqlparser.expression;
+
+import net.sf.jsqlparser.JSQLParserException;
+import net.sf.jsqlparser.test.TestUtils;
+import org.junit.jupiter.api.Test;
+
+
+class ConnectByRootOperatorTest {
+
+    @Test
+    void testCondition() throws JSQLParserException {
+        //@formatter:off
+        String sqlStr=
+                "SELECT EMP_ID,  EMP_NAME,\n" +
+                " \t  CONNECT_BY_ROOT (EMP_NAME || '_' || EMP_ID) AS ROOT_MANAGER,\n" +
+                " \t  SYS_CONNECT_BY_PATH(EMP_NAME, ' -> ') AS PATH\n" +
+                "    FROM EMPLOYEES\n" +
+                "    START WITH MANAGER_ID IS NULL\n" +
+                "    CONNECT BY PRIOR EMP_ID = MANAGER_ID";
+        //@formatter:on
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+    }
+}