Support "with" identifiers surrounded by backticks in GenericDialect (apache#1010)

Author: bitemyapp

src/dialect/mod.rs

@@ -95,7 +95,7 @@ pub trait Dialect: Debug + Any {
     /// MySQL, MS SQL, and sqlite). You can accept one of characters listed
     /// in `Word::matching_end_quote` here
     fn is_delimited_identifier_start(&self, ch: char) -> bool {
-        ch == '"'
+        ch == '"' || ch == '`'
     }
     /// Determine if quoted characters are proper for identifier
     fn is_proper_identifier_inside_quotes(&self, mut _chars: Peekable<Chars<'_>>) -> bool {

tests/sqlparser_hive.rs

@@ -20,7 +20,7 @@ use sqlparser::ast::{
     SelectItem, Statement, TableFactor, UnaryOperator, Value,
 };
 use sqlparser::dialect::{GenericDialect, HiveDialect};
-use sqlparser::parser::ParserError;
+use sqlparser::parser::{ParserError, ParserOptions};
 use sqlparser::test_utils::*;
 
 #[test]
@@ -32,6 +32,20 @@ fn parse_table_create() {
     hive().verified_stmt(iof);
 }
 
+fn generic(options: Option<ParserOptions>) -> TestedDialects {
+    TestedDialects {
+        dialects: vec![Box::new(GenericDialect {})],
+        options,
+    }
+}
+
+#[test]
+fn parse_describe() {
+    let describe = r#"DESCRIBE namespace.`table`"#;
+    hive().verified_stmt(describe);
+    generic(None).verified_stmt(describe);
+}
+
 #[test]
 fn parse_insert_overwrite() {
     let insert_partitions = r#"INSERT OVERWRITE TABLE db.new_table PARTITION (a = '1', b) SELECT a, b, c FROM db.table"#;
@@ -265,13 +279,8 @@ fn parse_create_function() {
         _ => unreachable!(),
     }
 
-    let generic = TestedDialects {
-        dialects: vec![Box::new(GenericDialect {})],
-        options: None,
-    };
-
     assert_eq!(
-        generic.parse_sql_statements(sql).unwrap_err(),
+        generic(None).parse_sql_statements(sql).unwrap_err(),
         ParserError::ParserError(
             "Expected an object type after CREATE, found: FUNCTION".to_string()
         )