Double quoted as string literal instead of identifier

common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/utils/StringUtils.java

@@ -49,13 +49,13 @@ public static String unquoteText(String text) {
   }
 
   /**
-   * Unquote Identifier which has " or ` as mark.
+   * Unquote Identifier which has ` as mark.
    * @param identifier identifier that possibly enclosed by double quotes or back ticks
    * @return An unquoted string whose outer pair of (double/back-tick) quotes have been
    *     removed
    */
   public static String unquoteIdentifier(String identifier) {
-    if (isQuoted(identifier, "\"") || isQuoted(identifier, "`")) {
+    if (isQuoted(identifier, "`")) {
       return identifier.substring(1, identifier.length() - 1);
     } else {
       return identifier;

docs/category.json

@@ -22,6 +22,7 @@
   ],
   "sql_cli": [
     "user/dql/expressions.rst",
+    "user/general/datatypes.rst",
     "user/general/identifiers.rst",
     "user/general/values.rst",
     "user/dql/basics.rst",

docs/experiment/ppl/general/datatypes.rst

@@ -222,5 +222,5 @@ Conversion from TIMESTAMP
 String Data Types
 =================
 
-TODO
+A string is a sequence of characters enclosed in either single or double quotes. For example, both 'text' and "text" will be treated as string literal.
 

docs/user/general/datatypes.rst

@@ -222,7 +222,16 @@ Conversion from TIMESTAMP
 String Data Types
 =================
 
-TODO
+A string is a sequence of characters enclosed in either single or double quotes. For example, both 'text' and "text" will be treated as string literal. To use quote characters in a string literal, you can include double quotes within single quoted string or single quotes within double quoted string::
+
+    od> SELECT 'hello', "world", '"hello"', "'world'"
+    fetched rows / total rows = 1/1
+    +-----------+-----------+-------------+-------------+
+    | 'hello'   | "world"   | '"hello"'   | "'world'"   |
+    |-----------+-----------+-------------+-------------|
+    | hello     | world     | "hello"     | 'world'     |
+    +-----------+-----------+-------------+-------------+
+
 
 
 

docs/user/general/identifiers.rst

@@ -56,7 +56,7 @@ Delimited Identifiers
 Description
 -----------
 
-A delimited identifier is an identifier enclosed in back ticks ````` or double quotation marks ``"``. In this case, the identifier enclosed is not necessarily a regular identifier. In other words, it can contain any special character not allowed by regular identifier.
+A delimited identifier is an identifier enclosed in back ticks `````. In this case, the identifier enclosed is not necessarily a regular identifier. In other words, it can contain any special character not allowed by regular identifier.
 
 Please note the difference between single quote and double quotes in SQL syntax. Single quote is used to enclose a string literal while double quotes have same purpose as back ticks to escape special characters in an identifier.
 

integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/sql/IdentifierIT.java

@@ -52,7 +52,6 @@ public void testSpecialIndexNames() throws IOException {
   public void testQuotedIndexNames() throws IOException {
     createIndexWithOneDoc("logs+2020+01", "logs.2020.01");
     queryAndAssertTheDoc("SELECT * FROM `logs+2020+01`");
-    queryAndAssertTheDoc("SELECT * FROM \"logs.2020.01\"");
   }
 
   @Test

integ-test/src/test/resources/correctness/queries/select.txt

@@ -4,7 +4,7 @@ SELECT `Cancelled`, `AvgTicketPrice` FROM kibana_sample_data_flights
 SELECT ABS(DistanceMiles), (FlightDelayMin * 2) - 3 FROM kibana_sample_data_flights
 SELECT abs(DistanceMiles), Abs(FlightDelayMin) FROM kibana_sample_data_flights
 SELECT Cancelled AS Cancel, AvgTicketPrice AS ATP FROM kibana_sample_data_flights
-SELECT Cancelled AS `Cancel`, AvgTicketPrice AS "ATP" FROM kibana_sample_data_flights
+SELECT Cancelled AS `Cancel` FROM kibana_sample_data_flights
 SELECT kibana_sample_data_flights.AvgTicketPrice FROM kibana_sample_data_flights
 SELECT flights.AvgTicketPrice, Carrier FROM kibana_sample_data_flights flights
 SELECT flights.AvgTicketPrice, Carrier FROM kibana_sample_data_flights AS flights

sql/src/main/antlr/OpenDistroSQLIdentifierParser.g4

@@ -48,7 +48,6 @@ qualifiedName
 
 ident
     : DOT? ID
-    | DOUBLE_QUOTE_ID
     | BACKTICK_QUOTE_ID
     | keywordsCanBeId
     ;

sql/src/main/antlr/OpenDistroSQLParser.g4

@@ -196,6 +196,7 @@ decimalLiteral
 
 stringLiteral
     : STRING_LITERAL
+    | DOUBLE_QUOTE_ID
     ;
 
 booleanLiteral

sql/src/test/java/com/amazon/opendistroforelasticsearch/sql/sql/antlr/SQLSyntaxParserTest.java

@@ -53,7 +53,7 @@ public void canParseSelectFieldWithAlias() {
 
   @Test
   public void canParseSelectFieldWithQuotedAlias() {
-    assertNotNull(parser.parse("SELECT name AS \"n\", age AS `a` FROM accounts"));
+    assertNotNull(parser.parse("SELECT name AS `n` FROM accounts"));
   }
 
   @Test
@@ -76,7 +76,6 @@ public void canNotParseIndexNameWithSpecialChar() {
   @Test
   public void canParseIndexNameWithSpecialCharQuoted() {
     assertNotNull(parser.parse("SELECT * FROM `hello+world`"));
-    assertNotNull(parser.parse("SELECT * FROM \"hello$world\""));
   }
 
   @Test

sql/src/test/java/com/amazon/opendistroforelasticsearch/sql/sql/parser/AstBuilderTest.java

@@ -62,10 +62,11 @@ public void can_build_select_literals() {
             values(emptyList()),
             alias("123", intLiteral(123)),
             alias("'hello'", stringLiteral("hello")),
+            alias("\"world\"", stringLiteral("world")),
             alias("false", booleanLiteral(false)),
             alias("-4.567", doubleLiteral(-4.567))
         ),
-        buildAST("SELECT 123, 'hello', false, -4.567")
+        buildAST("SELECT 123, 'hello', \"world\", false, -4.567")
     );
   }
 
@@ -137,19 +138,13 @@ public void can_build_select_fields_with_alias_quoted() {
     assertEquals(
         project(
             relation("test"),
-            alias(
-                "name",
-                qualifiedName("name"),
-                "first name"
-            ),
             alias(
                 "(age + 10)",
                 function("+", qualifiedName("age"), intLiteral(10)),
                 "Age_Expr"
             )
         ),
         buildAST("SELECT"
-                + " name AS \"first name\", "
                 + " (age + 10) AS `Age_Expr` "
                 + "FROM test"
         )

sql/src/test/java/com/amazon/opendistroforelasticsearch/sql/sql/parser/AstExpressionBuilderTest.java

@@ -62,6 +62,10 @@ public void canBuildStringLiteral() {
         stringLiteral("hello"),
         buildExprAst("'hello'")
     );
+    assertEquals(
+        stringLiteral("hello"),
+        buildExprAst("\"hello\"")
+    );
   }
 
   @Test

sql/src/test/java/com/amazon/opendistroforelasticsearch/sql/sql/parser/AstQualifiedNameBuilderTest.java

@@ -49,7 +49,6 @@ public void canBuildRegularIdentifierForElasticsearch() {
 
   @Test
   public void canBuildDelimitedIdentifier() {
-    buildFromIdentifier("\"hello$world\"").expectQualifiedName("hello$world");
     buildFromIdentifier("`logs.2020.01`").expectQualifiedName("logs.2020.01");
   }