dcapwell commented on code in PR #1962:
URL: https://github.com/apache/cassandra/pull/1962#discussion_r1042720633
##########
src/antlr/Parser.g:
##########
@@ -651,6 +717,102 @@ batchStatementObjective returns
[ModificationStatement.Parsed statement]
| d=deleteStatement { $statement = d; }
;
+/**
+ * ex. conditional update returning pre-update values
+ *
+ * BEGIN TRANSACTION
+ * LET row1 = (SELECT * FROM <table> WHERE k=1 AND c=2);
+ * LET row2 = (SELECT * FROM <table> WHERE k=2 AND c=2);
+ * SELECT row1.v, row2.v;
+ * IF row1.v = 3 AND row2.v = 4 THEN
+ * UPDATE <table> SET v = row1.v + 1 WHERE k = 1 AND c = 2;
+ * END IF
+ * COMMIT TRANSACTION
+ *
+ * ex. read-only transaction
+ *
+ * BEGIN TRANSACTION
+ * SELECT * FROM <table> WHERE k=1 AND c=2;
+ * COMMIT TRANSACTION
+ *
+ * ex. write-only transaction
+ *
+ * BEGIN TRANSACTION
+ * INSERT INTO <table> (k, c, v) VALUES (0, 0, 1);
+ * COMMIT TRANSACTION
+ */
+batchTxnStatement returns [TransactionStatement.Parsed expr]
+ @init {
+ isParsingTxn = true;
+ List<SelectStatement.RawStatement> assignments = new ArrayList<>();
+ SelectStatement.RawStatement select = null;
+ List<RowDataReference.Raw> returning = null;
+ List<ModificationStatement.Parsed> updates = new ArrayList<>();
+ }
+ : K_BEGIN K_TRANSACTION
+ ( let=letStatement ';' { assignments.add(let); })*
+ ( ( (selectStatement) => s=selectStatement ';' { select = s; }) | (
K_SELECT drs=rowDataReferences ';' { returning = drs; }) )?
+ ( K_IF conditions=txnConditions K_THEN { isTxnConditional = true; } )?
+ ( upd=batchStatementObjective ';' { updates.add(upd); } )*
+ ( {!isTxnConditional}? (K_COMMIT K_TRANSACTION) | {isTxnConditional}?
(K_END K_IF K_COMMIT K_TRANSACTION))
+ {
+ $expr = new TransactionStatement.Parsed(assignments, select,
returning, updates, conditions, references);
+ }
+ ;
+ finally { isParsingTxn = false; }
+
+rowDataReferences returns [List<RowDataReference.Raw> refs]
+ : r1=rowDataReference { refs = new ArrayList<RowDataReference.Raw>();
refs.add(r1); } (',' rN=rowDataReference { refs.add(rN); })*
+ ;
+
+rowDataReference returns [RowDataReference.Raw rawRef]
+ @init { Selectable.RawIdentifier tuple = null; Selectable.Raw selectable =
null; }
+ @after { $rawRef = newRowDataReference(tuple, selectable); }
+ : t=sident ('.' s=referenceSelection)? { tuple = t; selectable = s; }
+ ;
+
+referenceSelection returns [Selectable.Raw s]
+ : g=referenceSelectionWithoutField m=selectorModifier[g] {$s = m;}
+ ;
+
+referenceSelectionWithoutField returns [Selectable.Raw s]
+ @init { Selectable.Raw tmp = null; }
+ @after { $s = tmp; }
+ : sn=sident { tmp=sn; }
+ | (selectionTypeHint)=> h=selectionTypeHint { tmp=h; }
+ | t=selectionTupleOrNestedSelector { tmp=t; }
+ | l=selectionList { tmp=l; }
+ | m=selectionMapOrSet { tmp=m; }
+ // UDTs are equivalent to maps from the syntax point of view, so the final
decision will be done in Selectable.WithMapOrUdt
+ ;
+
+txnConditions returns [List<ConditionStatement.Raw> conditions]
+ @init { conditions = new ArrayList<ConditionStatement.Raw>(); }
+ : txnColumnCondition[conditions] ( K_AND txnColumnCondition[conditions] )*
Review Comment:
spoke in slack; pushed out of v1
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