MS SQL Server: add support for IDENTITY column option (#1432)

src/ast/ddl.rs

@@ -1050,6 +1050,20 @@ impl fmt::Display for ColumnOptionDef {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct IdentityProperty {
+    pub seed: Expr,
+    pub increment: Expr,
+}
+
+impl fmt::Display for IdentityProperty {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}, {}", self.seed, self.increment)
+    }
+}
+
 /// `ColumnOption`s are modifiers that follow a column definition in a `CREATE
 /// TABLE` statement.
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
@@ -1120,6 +1134,13 @@ pub enum ColumnOption {
     /// [1]: https://cloud.google.com/bigquery/docs/reference/standard-sql/data-definition-language#view_column_option_list
     /// [2]: https://cloud.google.com/bigquery/docs/reference/standard-sql/data-definition-language#column_option_list
     Options(Vec<SqlOption>),
+    /// MS SQL Server specific: Creates an identity column in a table.
+    /// Syntax
+    /// ```sql
+    /// IDENTITY [ (seed , increment) ]
+    /// ```
+    /// [MS SQL Server]: https://learn.microsoft.com/en-us/sql/t-sql/statements/create-table-transact-sql-identity-property
+    Identity(Option<IdentityProperty>),
 }
 
 impl fmt::Display for ColumnOption {
@@ -1221,6 +1242,13 @@ impl fmt::Display for ColumnOption {
             Options(options) => {
                 write!(f, "OPTIONS({})", display_comma_separated(options))
             }
+            Identity(parameters) => {
+                write!(f, "IDENTITY")?;
+                if let Some(parameters) = parameters {
+                    write!(f, "({parameters})")?;
+                }
+                Ok(())
+            }
         }
     }
 }

src/ast/mod.rs

@@ -36,8 +36,8 @@ pub use self::dcl::{AlterRoleOperation, ResetConfig, RoleOption, SetConfigValue,
 pub use self::ddl::{
     AlterColumnOperation, AlterIndexOperation, AlterTableOperation, ClusteredBy, ColumnDef,
     ColumnOption, ColumnOptionDef, ConstraintCharacteristics, Deduplicate, DeferrableInitial,
-    GeneratedAs, GeneratedExpressionMode, IndexOption, IndexType, KeyOrIndexDisplay, Owner,
-    Partition, ProcedureParam, ReferentialAction, TableConstraint,
+    GeneratedAs, GeneratedExpressionMode, IdentityProperty, IndexOption, IndexType,
+    KeyOrIndexDisplay, Owner, Partition, ProcedureParam, ReferentialAction, TableConstraint,
     UserDefinedTypeCompositeAttributeDef, UserDefinedTypeRepresentation, ViewColumnDef,
 };
 pub use self::dml::{CreateIndex, CreateTable, Delete, Insert};

src/parser/mod.rs

@@ -6069,6 +6069,20 @@ impl<'a> Parser<'a> {
             && dialect_of!(self is MySqlDialect | SQLiteDialect | DuckDbDialect | GenericDialect)
         {
             self.parse_optional_column_option_as()
+        } else if self.parse_keyword(Keyword::IDENTITY)
+            && dialect_of!(self is MsSqlDialect | GenericDialect)
+        {
+            let property = if self.consume_token(&Token::LParen) {
+                let seed = self.parse_number()?;
+                self.expect_token(&Token::Comma)?;
+                let increment = self.parse_number()?;
+                self.expect_token(&Token::RParen)?;
+
+                Some(IdentityProperty { seed, increment })
+            } else {
+                None
+            };
+            Ok(Some(ColumnOption::Identity(property)))
         } else {
             Ok(None)
         }

tests/sqlparser_mssql.rs

@@ -908,6 +908,117 @@ fn parse_create_table_with_invalid_options() {
     }
 }
 
+#[test]
+fn parse_create_table_with_identity_column() {
+    let with_column_options = [
+        (
+            r#"CREATE TABLE mytable (columnA INT IDENTITY NOT NULL)"#,
+            vec![
+                ColumnOptionDef {
+                    name: None,
+                    option: ColumnOption::Identity(None),
+                },
+                ColumnOptionDef {
+                    name: None,
+                    option: ColumnOption::NotNull,
+                },
+            ],
+        ),
+        (
+            r#"CREATE TABLE mytable (columnA INT IDENTITY(1, 1) NOT NULL)"#,
+            vec![
+                ColumnOptionDef {
+                    name: None,
+                    #[cfg(not(feature = "bigdecimal"))]
+                    option: ColumnOption::Identity(Some(IdentityProperty {
+                        seed: Expr::Value(Value::Number("1".to_string(), false)),
+                        increment: Expr::Value(Value::Number("1".to_string(), false)),
+                    })),
+                    #[cfg(feature = "bigdecimal")]
+                    option: ColumnOption::Identity(Some(IdentityProperty {
+                        seed: Expr::Value(Value::Number(bigdecimal::BigDecimal::from(1), false)),
+                        increment: Expr::Value(Value::Number(
+                            bigdecimal::BigDecimal::from(1),
+                            false,
+                        )),
+                    })),
+                },
+                ColumnOptionDef {
+                    name: None,
+                    option: ColumnOption::NotNull,
+                },
+            ],
+        ),
+    ];
+
+    for (sql, column_options) in with_column_options {
+        assert_eq!(
+            ms_and_generic().verified_stmt(sql),
+            Statement::CreateTable(CreateTable {
+                or_replace: false,
+                temporary: false,
+                external: false,
+                global: None,
+                if_not_exists: false,
+                transient: false,
+                volatile: false,
+                name: ObjectName(vec![Ident {
+                    value: "mytable".to_string(),
+                    quote_style: None,
+                },],),
+                columns: vec![ColumnDef {
+                    name: Ident {
+                        value: "columnA".to_string(),
+                        quote_style: None,
+                    },
+                    data_type: Int(None,),
+                    collation: None,
+                    options: column_options,
+                },],
+                constraints: vec![],
+                hive_distribution: HiveDistributionStyle::NONE,
+                hive_formats: Some(HiveFormat {
+                    row_format: None,
+                    serde_properties: None,
+                    storage: None,
+                    location: None,
+                },),
+                table_properties: vec![],
+                with_options: vec![],
+                file_format: None,
+                location: None,
+                query: None,
+                without_rowid: false,
+                like: None,
+                clone: None,
+                engine: None,
+                comment: None,
+                auto_increment_offset: None,
+                default_charset: None,
+                collation: None,
+                on_commit: None,
+                on_cluster: None,
+                primary_key: None,
+                order_by: None,
+                partition_by: None,
+                cluster_by: None,
+                clustered_by: None,
+                options: None,
+                strict: false,
+                copy_grants: false,
+                enable_schema_evolution: None,
+                change_tracking: None,
+                data_retention_time_in_days: None,
+                max_data_extension_time_in_days: None,
+                default_ddl_collation: None,
+                with_aggregation_policy: None,
+                with_row_access_policy: None,
+                with_tags: None,
+            }),
+        );
+    }
+}
+
 fn ms() -> TestedDialects {
     TestedDialects {
         dialects: vec![Box::new(MsSqlDialect {})],