Introduce support for mysql index hints (fixing issue #374) (#429)

* Introduce support for mysql index hints (fixing issue #374)

* Fix checkstyle errors
-Converted indent tabs to spaces
-Added missing {} on single-line if statement

Author: joeymart

src/main/java/net/sf/jsqlparser/expression/MySQLIndexHint.java

@@ -0,0 +1,52 @@
+/*
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2017 JSQLParser
+ * %%
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 2.1 of the
+ * License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Lesser Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Lesser Public
+ * License along with this program.  If not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ * #L%
+ */
+package net.sf.jsqlparser.expression;
+
+import java.util.List;
+
+public class MySQLIndexHint  {
+
+    private final String action;
+    private final String indexQualifier;
+    private final List<String> indexNames;
+
+    public MySQLIndexHint(String action, String indexQualifier, List<String> indexNames) {
+        this.action = action;
+        this.indexQualifier = indexQualifier;
+        this.indexNames = indexNames;
+    }
+
+    @Override
+    public String toString() {
+        // use|ignore|force key|index (index1,...,indexN)
+        StringBuilder buffer = new StringBuilder();
+        buffer.append(" ").append(action).append(" ").append(indexQualifier).append(" (");
+        for (int i = 0; i < indexNames.size(); i++) {
+            if (i > 0) {
+                buffer.append(",");
+            }
+            buffer.append(indexNames.get(i));
+        }
+        buffer.append(")");
+        return buffer.toString();
+    }
+}

src/main/java/net/sf/jsqlparser/schema/Table.java

@@ -36,6 +36,7 @@ public class Table extends ASTNodeAccessImpl implements FromItem, MultiPartName
 
     private Alias alias;
     private Pivot pivot;
+    private MySQLIndexHint hint;
 
     public Table() {
     }
@@ -133,10 +134,19 @@ public void setPivot(Pivot pivot) {
         this.pivot = pivot;
     }
 
+    public MySQLIndexHint getIndexHint() {
+        return hint;
+    }
+
+    public void setHint(MySQLIndexHint hint) {
+        this.hint = hint;
+    }
+
     @Override
     public String toString() {
         return getFullyQualifiedName()
                 + ((pivot != null) ? " " + pivot : "")
-                + ((alias != null) ? alias.toString() : "");
+                + ((alias != null) ? alias.toString() : "")
+                + ((hint != null) ? hint.toString() : "");
     }
 }

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

@@ -232,6 +232,10 @@ public void visit(Table tableName) {
         if (alias != null) {
             buffer.append(alias);
         }
+        MySQLIndexHint indexHint = tableName.getIndexHint();
+        if (indexHint != null) {
+            buffer.append(indexHint);
+        }
     }
 
     @Override

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

@@ -263,6 +263,8 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_NOVALIDATE : "NOVALIDATE">
 |   <K_ENABLE : "ENABLE">
 |   <K_DISABLE : "DISABLE">
+|   <K_USE : "USE">
+|   <K_FORCE : "FORCE">
 }
 
 TOKEN : /* Stuff */
@@ -1077,6 +1079,38 @@ Alias Alias():
    { return new Alias(name,useAs); }
 }
 
+MySQLIndexHint MySQLIndexHint():
+{
+	Token actionToken = null;
+	Token indexToken = null;
+	String indexName = null;
+	List<String> indexNameList = new ArrayList<String>();
+}
+{
+	(actionToken = <K_USE>
+	| actionToken = <K_IGNORE>
+	| actionToken = <K_FORCE> )
+	(indexToken = <K_INDEX>
+	| indexToken = <K_KEY>)
+	"("
+	indexName = Identifier() { indexNameList.add(indexName); }
+	("," indexName= Identifier() { indexNameList.add(indexName); })*
+	")"
+	{
+		return new MySQLIndexHint(actionToken.image, indexToken.image, indexNameList);
+	}
+}
+
+String Identifier():
+{
+	Token tk = null;
+}
+{
+	(tk=<S_IDENTIFIER>
+    | tk=<S_QUOTED_IDENTIFIER>)
+    { return tk.image; }
+}
+
 FunctionItem FunctionItem():
 {
     Alias alias = null;
@@ -1224,6 +1258,7 @@ FromItem FromItem():
     FromItem fromItem = null;
     Pivot pivot = null;
     Alias alias = null;
+    MySQLIndexHint indexHint = null;
 }
 {
     (
@@ -1251,6 +1286,13 @@ FromItem FromItem():
             )
             [(LOOKAHEAD(2) pivot=PivotXml()|pivot=Pivot()) { fromItem.setPivot(pivot); } ]
             [ alias=Alias() { fromItem.setAlias(alias); } ]
+            [
+                LOOKAHEAD(2)
+                indexHint=MySQLIndexHint() {
+                    if (fromItem instanceof Table)
+						((Table) fromItem).setHint(indexHint);
+                }
+            ]
         )
     )
     {

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

@@ -2578,4 +2578,22 @@ public void testForUpdateWaitWithTimeout() throws JSQLParserException {
 //    public void testSubSelectFailsIssue394_2() throws JSQLParserException {
 //        assertSqlCanBeParsedAndDeparsed("select * from all");
 //    }
+
+    public void testMysqlIndexHints() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM testtable AS t0 USE INDEX (index1)");
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM testtable AS t0 IGNORE INDEX (index1)");
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM testtable AS t0 FORCE INDEX (index1)");
+    }
+
+    public void testMysqlIndexHintsWithJoins() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM table0 t0 INNER JOIN table1 t1 USE INDEX (index1)");
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM table0 t0 INNER JOIN table1 t1 IGNORE INDEX (index1)");
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM table0 t0 INNER JOIN table1 t1 FORCE INDEX (index1)");
+    }
+
+    public void testMysqlMultipleIndexHints() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM testtable AS t0 USE INDEX (index1,index2)");
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM testtable AS t0 IGNORE INDEX (index1,index2)");
+        assertSqlCanBeParsedAndDeparsed("SELECT column FROM testtable AS t0 FORCE INDEX (index1,index2)");
+    }
 }