fixes #842

Author: wumpz

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

@@ -3017,13 +3017,22 @@ JsonExpression JsonExpression() : {
 
 IntervalExpression IntervalExpression() : {
     IntervalExpression interval;
-    Token token;
+    Token token = null;
+    Expression expr = null;
     boolean signed = false;
 }
 {
-    { interval = new IntervalExpression(); }
-    <K_INTERVAL> ["-" {signed=true;}] (token=<S_LONG> | token=<S_DOUBLE> | token=<S_CHAR_LITERAL> ) 
-    { interval.setParameter((signed?"-":"") + token.image); }
+    
+{ interval = new IntervalExpression(); }
+    <K_INTERVAL> ["-" {signed=true;}] (token=<S_LONG> | token=<S_DOUBLE> | token=<S_CHAR_LITERAL> | expr = Column()) 
+    { 
+        if (expr != null) {
+            if (signed) expr = new SignedExpression('-', expr);
+            interval.setExpression(expr);
+        } else {
+            interval.setParameter((signed?"-":"") + token.image); 
+        }
+    }
     [ LOOKAHEAD(2) (token = <S_IDENTIFIER> | token = <K_DATE_LITERAL>) { interval.setIntervalType(token.image); } ]
     {
         return interval;

src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java

@@ -3769,9 +3769,27 @@ public void testArrayIssue489() throws JSQLParserException {
     public void testArrayIssue377() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("select 'yelp'::name as pktable_cat, n2.nspname as pktable_schem, c2.relname as pktable_name, a2.attname as pkcolumn_name, 'yelp'::name as fktable_cat, n1.nspname as fktable_schem, c1.relname as fktable_name, a1.attname as fkcolumn_name, i::int2 as key_seq, case ref.confupdtype when 'c' then 0::int2 when 'n' then 2::int2 when 'd' then 4::int2 when 'r' then 1::int2 else 3::int2 end as update_rule, case ref.confdeltype when 'c' then 0::int2 when 'n' then 2::int2 when 'd' then 4::int2 when 'r' then 1::int2 else 3::int2 end as delete_rule, ref.conname as fk_name, cn.conname as pk_name, case when ref.condeferrable then case when ref.condeferred then 5::int2 else 6::int2 end else 7::int2 end as deferrablity from ((((((( (select cn.oid, conrelid, conkey, confrelid, confkey, generate_series(array_lower(conkey, 1), array_upper(conkey, 1)) as i, confupdtype, confdeltype, conname, condeferrable, condeferred from pg_catalog.pg_constraint cn, pg_catalog.pg_class c, pg_catalog.pg_namespace n where contype = 'f' and conrelid = c.oid and relname = 'business' and n.oid = c.relnamespace and n.nspname = 'public' ) ref inner join pg_catalog.pg_class c1 on c1.oid = ref.conrelid) inner join pg_catalog.pg_namespace n1 on n1.oid = c1.relnamespace) inner join pg_catalog.pg_attribute a1 on a1.attrelid = c1.oid and a1.attnum = conkey[i]) inner join pg_catalog.pg_class c2 on c2.oid = ref.confrelid) inner join pg_catalog.pg_namespace n2 on n2.oid = c2.relnamespace) inner join pg_catalog.pg_attribute a2 on a2.attrelid = c2.oid and a2.attnum = confkey[i]) left outer join pg_catalog.pg_constraint cn on cn.conrelid = ref.confrelid and cn.contype = 'p') order by ref.oid, ref.i", true);
     }
-    
+
     @Test
     public void testArrayIssue378() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("select ta.attname, ia.attnum, ic.relname, n.nspname, tc.relname from pg_catalog.pg_attribute ta, pg_catalog.pg_attribute ia, pg_catalog.pg_class tc, pg_catalog.pg_index i, pg_catalog.pg_namespace n, pg_catalog.pg_class ic where tc.relname = 'business' and n.nspname = 'public' and tc.oid = i.indrelid and n.oid = tc.relnamespace and i.indisprimary = 't' and ia.attrelid = i.indexrelid and ta.attrelid = i.indrelid and ta.attnum = i.indkey[ia.attnum-1] and (not ta.attisdropped) and (not ia.attisdropped) and ic.oid = i.indexrelid order by ia.attnum", true);
-    } 
+    }
+
+    @Test
+    public void testIssue842() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT a.id lendId, "
+                + "a.lend_code                                            lendCode, "
+                + "a.amount, "
+                + "a.remaining_principal                                  remainingPrincipal, "
+                + "a.interest_rate                                        interestRate, "
+                + "date_add(a.lend_time, INTERVAL a.repayment_period DAY) lendEndTime, "
+                + "a.lend_time                                            lendTime "
+                + "FROM risk_lend a "
+                + "WHERE a.loan_id = 1", true);
+    }
+
+    @Test
+    public void testIssue842_2() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT INTERVAL a.repayment_period DAY");
+    }
 }