From 809286d325de24eaf6f20ab39c17714730f5d989 Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Wed, 26 Sep 2018 11:42:10 +0200
Subject: [PATCH] [#7518] Add support for parsing DATEDIFF(d1, d2)

---
 .../main/resources/org/jooq/web/grammar-3.12.txt |  1 +
 jOOQ/src/main/java/org/jooq/impl/ParserImpl.java | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt b/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt
index 27f8514940..d7ab1707df 100644
--- a/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt
+++ b/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt
@@ -655,6 +655,7 @@ term =
 | 'CURTIME' '(' ')'
 | dateLiteral
 | 'DATEADD' '(' datePart ',' field ',' field ')'
+| 'DATEDIFF' '(' [ datePart ',' ] field ',' field ')'
 | 'DATE_TRUNC' '(' stringLiteral ',' field ')'
 | 'DAY' '(' field ')'
 | 'DAYOFMONTH' '(' field ')'
diff --git a/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java b/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
index 93199d6c64..0fa6d6ada0 100644
--- a/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
@@ -4530,6 +4530,8 @@ final class ParserImpl implements Parser {
                         return field;
                     else if ((field = parseFieldDateAddIf(ctx)) != null)
                         return field;
+                    else if ((field = parseFieldDateDiffIf(ctx)) != null)
+                        return field;
 
                 if (N.is(type))
                     if ((field = parseFieldDenseRankIf(ctx)) != null)
@@ -5504,6 +5506,20 @@ final class ParserImpl implements Parser {
         return null;
     }
 
+    private static final Field<?> parseFieldDateDiffIf(ParserContext ctx) {
+        if (parseFunctionNameIf(ctx, "DATEDIFF")) {
+            parse(ctx, '(');
+            Field<Date> d1 = (Field<Date>) parseField(ctx, Type.D);
+            parse(ctx, ',');
+            Field<Date> d2 = (Field<Date>) parseField(ctx, Type.D);
+            parse(ctx, ')');
+
+            return DSL.dateDiff(d1, d2);
+        }
+
+        return null;
+    }
+
     private static final Date parseDateLiteral(ParserContext ctx) {
         try {
             return Date.valueOf(parseStringLiteral(ctx));