Support parsing SELECT FOR UPDATE NOWAIT - Refer to documents on https://docs.oracle.com/cd/E17952_01/mysql-8.0-en/innodb-locking-reads.html#innodb-locking-reads-nowait-skip-locked (#896)

Author: KyongSik-Yoon

src/main/java/net/sf/jsqlparser/statement/select/PlainSelect.java

@@ -49,6 +49,7 @@ public class PlainSelect extends ASTNodeAccessImpl implements SelectBody {
     private boolean sqlNoCacheFlag = false;
     private String forXmlPath;
     private KSQLWindow ksqlWindow = null;
+    private boolean noWait = false;
 
     public boolean isUseBrackets() {
         return useBrackets;
@@ -396,6 +397,10 @@ public String toString() {
                     // Wait's toString will do the formatting for us
                     sql.append(wait);
                 }
+
+                if (isNoWait()) {
+                    sql.append(" NOWAIT");
+                }
             }
             if (optimizeFor != null) {
                 sql.append(optimizeFor);
@@ -506,4 +511,12 @@ public boolean getMySqlSqlCalcFoundRows() {
     public boolean getMySqlSqlNoCache() {
         return this.sqlNoCacheFlag;
     }
+
+    public void setNoWait(boolean noWait) {
+        this.noWait = noWait;
+    }
+
+    public boolean isNoWait() {
+        return this.noWait;
+    }
 }

src/main/java/net/sf/jsqlparser/util/deparser/SelectDeParser.java

@@ -165,6 +165,9 @@ public void visit(PlainSelect plainSelect) {
                 // wait's toString will do the formatting for us
                 buffer.append(plainSelect.getWait());
             }
+            if (plainSelect.isNoWait()) {
+                buffer.append(" NOWAIT");
+            }
         }
         if (plainSelect.getOptimizeFor() != null) {
             deparseOptimizeFor(plainSelect.getOptimizeFor());

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

@@ -233,6 +233,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_NOVALIDATE : "NOVALIDATE">
 |   <K_NULL:"NULL">
 |   <K_NULLS: "NULLS">
+|   <K_NOWAIT: "NOWAIT">
 |   <K_OF:"OF">
 |   <K_OFFSET:"OFFSET">
 |   <K_ON:"ON">
@@ -1276,7 +1277,8 @@ PlainSelect PlainSelect() #PlainSelect:
     Wait wait = null;
     boolean mySqlSqlCalcFoundRows = false;
     Token token;
-    KSQLWindow ksqlWindow=null;
+    KSQLWindow ksqlWindow = null;
+    boolean noWait = false;
 }
 {
     <K_SELECT>
@@ -1332,9 +1334,10 @@ PlainSelect PlainSelect() #PlainSelect:
 
     [LOOKAHEAD(<K_FETCH>) fetch = Fetch() { plainSelect.setFetch(fetch);    } ]
 
-    [ LOOKAHEAD(2) <K_FOR> <K_UPDATE> { plainSelect.setForUpdate(true); }
+    [LOOKAHEAD(2) <K_FOR> <K_UPDATE> { plainSelect.setForUpdate(true); }
         [ <K_OF> updateTable = Table() { plainSelect.setForUpdateTable(updateTable); } ]
-        [ LOOKAHEAD(<K_WAIT>) wait = Wait() { plainSelect.setWait(wait); } ] ]
+        [ LOOKAHEAD(<K_WAIT>) wait = Wait() { plainSelect.setWait(wait); } ]
+        [ <K_NOWAIT> { plainSelect.setNoWait(true); } ] ]
 
     [LOOKAHEAD(<K_OPTIMIZE>) optimize = OptimizeFor() { plainSelect.setOptimizeFor(optimize); } ]
 

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

@@ -3136,6 +3136,11 @@ public void testForUpdateWaitWithTimeout() throws JSQLParserException {
         assertEquals("wait time should be 60", waitTime, 60L);
     }
 
+    @Test
+    public void testForUpdateNoWait() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT * FROM mytable FOR UPDATE NOWAIT");
+    }
+
 //    @Test public void testSubSelectFailsIssue394() throws JSQLParserException {
 //        assertSqlCanBeParsedAndDeparsed("select aa.* , t.* from accenter.all aa, (select a.* from pacioli.emc_plan a) t");
 //    }