MsSql: Keep the comma separator when displaying DECLARE lists (#2671)

Author: LucaCappelletti94

src/ast/mod.rs

@@ -3124,6 +3124,22 @@ impl fmt::Display for DeclareType {
     }
 }
 
+/// Separator written between the declarations collected by one `DECLARE` keyword.
+#[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Hash, Default)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub enum DeclareSeparator {
+    /// Each declaration ends with `;`, as in a Snowflake Scripting `DECLARE` section.
+    ///
+    /// [Snowflake](https://docs.snowflake.com/en/sql-reference/snowflake-scripting/declare)
+    #[default]
+    Semicolon,
+    /// One comma-separated list, as in `DECLARE @a INT, @b INT`.
+    ///
+    /// [MsSql](https://learn.microsoft.com/en-us/sql/t-sql/language-elements/declare-local-variable-transact-sql)
+    Comma,
+}
+
 /// A `DECLARE` statement.
 /// [PostgreSQL] [Snowflake] [BigQuery]
 ///
@@ -4068,6 +4084,8 @@ pub enum Statement {
     Declare {
         /// Cursor declaration statements collected by `DECLARE`.
         stmts: Vec<Declare>,
+        /// Separator between `stmts` in the rendered SQL.
+        separator: DeclareSeparator,
     },
     /// ```sql
     /// CREATE EXTENSION [ IF NOT EXISTS ] extension_name
@@ -5246,9 +5264,12 @@ impl fmt::Display for Statement {
                 write!(f, "{statement}")
             }
             Statement::Query(s) => s.fmt(f),
-            Statement::Declare { stmts } => {
-                write!(f, "DECLARE ")?;
-                write!(f, "{}", display_separated(stmts, "; "))
+            Statement::Declare { stmts, separator } => {
+                let sep = match separator {
+                    DeclareSeparator::Comma => ", ",
+                    DeclareSeparator::Semicolon => "; ",
+                };
+                write!(f, "DECLARE {}", display_separated(stmts, sep))
             }
             Statement::Fetch {
                 name,

src/parser/mod.rs

@@ -8030,6 +8030,7 @@ impl<'a> Parser<'a> {
                 hold,
                 for_query: query,
             }],
+            separator: DeclareSeparator::Semicolon,
         })
     }
 
@@ -8073,6 +8074,7 @@ impl<'a> Parser<'a> {
                 hold: None,
                 for_query: None,
             }],
+            separator: DeclareSeparator::Semicolon,
         })
     }
 
@@ -8189,7 +8191,10 @@ impl<'a> Parser<'a> {
             break;
         }
 
-        Ok(Statement::Declare { stmts })
+        Ok(Statement::Declare {
+            stmts,
+            separator: DeclareSeparator::Semicolon,
+        })
     }
 
     /// Parse a [MsSql] `DECLARE` statement.
@@ -8206,7 +8211,10 @@ impl<'a> Parser<'a> {
     pub fn parse_mssql_declare(&mut self) -> Result<Statement, ParserError> {
         let stmts = self.parse_comma_separated(Parser::parse_mssql_declare_stmt)?;
 
-        Ok(Statement::Declare { stmts })
+        Ok(Statement::Declare {
+            stmts,
+            separator: DeclareSeparator::Comma,
+        })
     }
 
     /// Parse the body of a [MsSql] `DECLARE`statement.

tests/sqlparser_bigquery.rs

@@ -2191,7 +2191,7 @@ fn parse_big_query_declare() {
         ),
     ] {
         match bigquery().verified_stmt(sql) {
-            Statement::Declare { mut stmts } => {
+            Statement::Declare { mut stmts, .. } => {
                 assert_eq!(1, stmts.len());
                 let Declare {
                     names,

tests/sqlparser_mssql.rs

@@ -1475,7 +1475,8 @@ fn parse_mssql_declare() {
                     hold: None,
                     for_query: None
                 }
-            ]
+            ],
+            separator: DeclareSeparator::Comma,
         }],
         ast
     );
@@ -1495,7 +1496,8 @@ fn parse_mssql_declare() {
                     scroll: None,
                     hold: None,
                     for_query: None
-                }]
+                }],
+                separator: DeclareSeparator::Comma,
             },
             Statement::Set(Set::SingleAssignment {
                 scope: None,
@@ -3004,3 +3006,10 @@ fn parse_create_proc() {
         .expect_err("PROC should remain MSSQL-specific");
     ms_and_generic().verified_stmt("SELECT proc FROM jobs");
 }
+
+#[test]
+fn parse_mssql_declare_comma_list_display() {
+    ms().verified_stmt("DECLARE @a INT, @b INT");
+    ms().verified_stmt("DECLARE @a INT = 1, @b TEXT = 'x'");
+    ms().verified_stmt("DECLARE @foo CURSOR, @bar INT");
+}

tests/sqlparser_snowflake.rs

@@ -1739,7 +1739,7 @@ fn parse_snowflake_declare_cursor() {
         ),
     ] {
         match snowflake().verified_stmt(sql) {
-            Statement::Declare { mut stmts } => {
+            Statement::Declare { mut stmts, .. } => {
                 assert_eq!(1, stmts.len());
                 let Declare {
                     names,
@@ -1807,7 +1807,7 @@ fn parse_snowflake_declare_result_set() {
         ("DECLARE res RESULTSET", "res", None),
     ] {
         match snowflake().verified_stmt(sql) {
-            Statement::Declare { mut stmts } => {
+            Statement::Declare { mut stmts, .. } => {
                 assert_eq!(1, stmts.len());
                 let Declare {
                     names,
@@ -1860,7 +1860,7 @@ fn parse_snowflake_declare_exception() {
         ("DECLARE ex EXCEPTION", "ex", None),
     ] {
         match snowflake().verified_stmt(sql) {
-            Statement::Declare { mut stmts } => {
+            Statement::Declare { mut stmts, .. } => {
                 assert_eq!(1, stmts.len());
                 let Declare {
                     names,
@@ -1900,7 +1900,7 @@ fn parse_snowflake_declare_variable() {
         ("DECLARE profit", "profit", None, None),
     ] {
         match snowflake().verified_stmt(sql) {
-            Statement::Declare { mut stmts } => {
+            Statement::Declare { mut stmts, .. } => {
                 assert_eq!(1, stmts.len());
                 let Declare {
                     names,
@@ -1950,7 +1950,7 @@ fn parse_snowflake_declare_multi_statements() {
         "ex EXCEPTION (-20003, 'ERROR: Could not create table.')"
     );
     match snowflake().verified_stmt(sql) {
-        Statement::Declare { stmts } => {
+        Statement::Declare { stmts, .. } => {
             let actual = stmts
                 .iter()
                 .map(|stmt| (stmt.names[0].value.as_str(), stmt.declare_type.clone()))