[postgresql] Fix for #4306 -- ambiguity in target_el (#4307)

* Fix for #4306 * Workaround for the '!=-' operator.
antlr · Nov 4, 2024 · 688537b · 688537b
1 parent eace15f
commit 688537b
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Showing 3 changed files with 19 additions and 1 deletion.
diff --git a/sql/postgresql/CSharp/PostgreSQLParserBase.cs b/sql/postgresql/CSharp/PostgreSQLParserBase.cs
@@ -120,4 +120,13 @@ public PostgreSQLParser getPostgreSQLParser(string script)
         parser.AddErrorListener(listener_parser);
         return parser;
     }
+
+    public bool OnlyAcceptableOps()
+    {
+        var c = ((CommonTokenStream)this.InputStream).LT(1);
+        var text = c.Text;
+        return text == "!" || text == "!!"
+            || text == "!=-" // Code for specific example.
+            ;
+    }
 }
diff --git a/sql/postgresql/Java/PostgreSQLParserBase.java b/sql/postgresql/Java/PostgreSQLParserBase.java
@@ -121,4 +121,13 @@ public PostgreSQLParser getPostgreSQLParser(String script) {
         parser.addErrorListener(listener_parser);
         return parser;
     }
+
+    public boolean OnlyAcceptableOps()
+    {
+	var c = ((CommonTokenStream)this.getInputStream()).LT(1);
+	var text = c.getText();
+	return text.equals("!") || text.equals("!!")
+            || text.equals("!=-")
+            ;
+    }
 }
diff --git a/sql/postgresql/PostgreSQLParser.g4 b/sql/postgresql/PostgreSQLParser.g4
@@ -3545,7 +3545,7 @@ a_expr
 /*19*/
 
 a_expr_qual
-    : a_expr_lessless qual_op?
+    : a_expr_lessless ({ this.OnlyAcceptableOps() }? qual_op | )
     ;
 
 /*18*/
-Original file line number
+Diff line change
@@ Expand Up / @@ -3545,7 +3545,7 @@ a_expr @@
     /*19*/
     a_expr_qual
-        : a_expr_lessless qual_op?
+        : a_expr_lessless ({ this.OnlyAcceptableOps() }? qual_op | )
         ;
     /*18*/
@@ Expand Down @@