Refactor extract delete where segments (#34988)

Author: FlyingZC

infra/binder/src/main/java/org/apache/shardingsphere/infra/binder/context/statement/dml/DeleteStatementContext.java

@@ -56,11 +56,15 @@ public final class DeleteStatementContext extends CommonSQLStatementContext impl
     public DeleteStatementContext(final DeleteStatement sqlStatement) {
         super(sqlStatement);
         tablesContext = new TablesContext(getAllSimpleTableSegments());
-        getSqlStatement().getWhere().ifPresent(whereSegments::add);
+        extractWhereSegments(whereSegments, sqlStatement);
         ColumnExtractor.extractColumnSegments(columnSegments, whereSegments);
         ExpressionExtractor.extractJoinConditions(joinConditions, whereSegments);
     }
 
+    private void extractWhereSegments(final Collection<WhereSegment> whereSegments, final DeleteStatement deleteStatement) {
+        deleteStatement.getWhere().ifPresent(whereSegments::add);
+    }
+    
     private Collection<SimpleTableSegment> getAllSimpleTableSegments() {
         TableExtractor tableExtractor = new TableExtractor();
         tableExtractor.extractTablesFromDelete(getSqlStatement());