From d0a782d8cccbc06ae85c19797292f98079b3c9d4 Mon Sep 17 00:00:00 2001
From: Nickolay Ponomarev <asqueella@gmail.com>
Date: Sat, 4 May 2019 02:12:08 +0300
Subject: [PATCH] [mssql] Support delimited identifiers in [square brackets]

T-SQL supports non-standard `[...]` quoting in addition to the widely
supported and standard `"..."`:

https://docs.microsoft.com/en-us/sql/relational-databases/databases/database-identifiers?view=sql-server-2017
---
 src/dialect/mssql.rs     | 4 ++++
 tests/sqlparser_mssql.rs | 9 ++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/dialect/mssql.rs b/src/dialect/mssql.rs
index 65daeb8d..4ed1d00f 100644
--- a/src/dialect/mssql.rs
+++ b/src/dialect/mssql.rs
@@ -4,6 +4,10 @@ use crate::dialect::Dialect;
 pub struct MsSqlDialect {}
 
 impl Dialect for MsSqlDialect {
+    fn is_delimited_identifier_start(&self, ch: char) -> bool {
+        ch == '"' || ch == '['
+    }
+
     fn is_identifier_start(&self, ch: char) -> bool {
         // See https://docs.microsoft.com/en-us/sql/relational-databases/databases/database-identifiers?view=sql-server-2017#rules-for-regular-identifiers
         // We don't support non-latin "letters" currently.
diff --git a/tests/sqlparser_mssql.rs b/tests/sqlparser_mssql.rs
index d209ed94..eb5e0596 100644
--- a/tests/sqlparser_mssql.rs
+++ b/tests/sqlparser_mssql.rs
@@ -27,7 +27,14 @@ fn parse_mssql_identifiers() {
     };
 }
 
-#[allow(dead_code)]
+#[test]
+fn parse_mssql_delimited_identifiers() {
+    let _ = ms().one_statement_parses_to(
+        "SELECT [a.b!] [FROM] FROM foo [WHERE]",
+        "SELECT [a.b!] AS [FROM] FROM foo AS [WHERE]",
+    );
+}
+
 fn ms() -> TestedDialects {
     TestedDialects {
         dialects: vec![Box::new(MsSqlDialect {})],