Add support MySQL named UNIQUE index in ALTER TABLE

src/main/java/net/sf/jsqlparser/statement/alter/AlterExpression.java

@@ -19,7 +19,6 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
-
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.statement.ReferentialAction;
 import net.sf.jsqlparser.statement.ReferentialAction.Action;
@@ -59,6 +58,7 @@ public class AlterExpression implements Serializable {
     private String fkSourceTable;
     private List<String> fkSourceColumns;
     private boolean uk;
+    private boolean ukTypeSpecified;
     private boolean useEqual;
 
     private List<String> partitions;
@@ -533,6 +533,15 @@ public boolean getUk() {
 
     public void setUk(boolean uk) {
         this.uk = uk;
+        this.ukTypeSpecified = true;
+    }
+
+    public boolean isUkTypeSpecified() {
+        return ukTypeSpecified;
+    }
+
+    public void setUkTypeSpecified(boolean ukTypeSpecified) {
+        this.ukTypeSpecified = ukTypeSpecified;
     }
 
     public boolean isUseIfNotExists() {
@@ -929,10 +938,14 @@ public String toString() {
             } else if (ukColumns != null) {
                 b.append("UNIQUE");
                 if (ukName != null) {
-                    if (getUk()) {
-                        b.append(" KEY ");
+                    if (isUkTypeSpecified()) {
+                        if (getUk()) {
+                            b.append(" KEY ");
+                        } else {
+                            b.append(" INDEX ");
+                        }
                     } else {
-                        b.append(" INDEX ");
+                        b.append(" ");
                     }
                     b.append(ukName);
                 }

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

@@ -10220,7 +10220,20 @@ AlterExpression AlterExpression():
                     ")"
                 )
                 |
-                ( <K_UNIQUE> ((<K_KEY> { alterExp.setUk(true); } | <K_INDEX>) (tk=<S_IDENTIFIER> | tk=<S_QUOTED_IDENTIFIER>) { alterExp.setUkName(tk.image); } )?
+                (
+                    <K_UNIQUE>
+                    (
+                        (
+                            <K_KEY> { alterExp.setUk(true); }
+                            | <K_INDEX> { alterExp.setUk(false); }
+                        )
+                        [ (tk=<S_IDENTIFIER> | tk=<S_QUOTED_IDENTIFIER>) { alterExp.setUkName(tk.image); } ]
+                        |
+                        (tk=<S_IDENTIFIER> | tk=<S_QUOTED_IDENTIFIER>) {
+                            alterExp.setUkTypeSpecified(false);
+                            alterExp.setUkName(tk.image);
+                        }
+                    )?
                     columnNames=ColumnsNamesList() { alterExp.setUkColumns(columnNames); }
                     [
                         <K_USING> { alterExp.addParameters("USING"); }

src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java

@@ -161,6 +161,11 @@ public void testAlterTableUniqueKey() throws JSQLParserException {
                 "ALTER TABLE `schema_migrations` ADD UNIQUE KEY `unique_schema_migrations` (`version`)");
     }
 
+    @Test
+    public void testAlterTableUniqueNamedWithoutKeyword() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE `goods` ADD UNIQUE `aaa` (`cate_id`)");
+    }
+
     @Test
     public void testAlterTableForgeignKey() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed(