Add support for MiscTests90 parsing features

ast/alter_database_set_statement.go

@@ -130,7 +130,9 @@ func (a *AlterDatabaseAddFileGroupStatement) statement() {}
 
 // AlterDatabaseModifyFileStatement represents ALTER DATABASE ... MODIFY FILE statement
 type AlterDatabaseModifyFileStatement struct {
-	DatabaseName *Identifier
+	DatabaseName    *Identifier
+	FileDeclaration *FileDeclaration
+	UseCurrent      bool
 }
 
 func (a *AlterDatabaseModifyFileStatement) node()      {}
@@ -176,6 +178,15 @@ type AlterDatabaseRemoveFileGroupStatement struct {
 func (a *AlterDatabaseRemoveFileGroupStatement) node()      {}
 func (a *AlterDatabaseRemoveFileGroupStatement) statement() {}
 
+// AlterDatabaseCollateStatement represents ALTER DATABASE ... COLLATE statement
+type AlterDatabaseCollateStatement struct {
+	DatabaseName *Identifier
+	Collation    *Identifier
+}
+
+func (a *AlterDatabaseCollateStatement) node()      {}
+func (a *AlterDatabaseCollateStatement) statement() {}
+
 // AlterDatabaseScopedConfigurationClearStatement represents ALTER DATABASE SCOPED CONFIGURATION CLEAR statement
 type AlterDatabaseScopedConfigurationClearStatement struct {
 	Option    *DatabaseConfigurationClearOption

ast/alter_table_drop_table_element_statement.go

@@ -54,8 +54,17 @@ func (*DropClusteredConstraintValueOption) dropClusteredConstraintOption()  {}
 
 // FileGroupOrPartitionScheme represents a filegroup or partition scheme reference.
 type FileGroupOrPartitionScheme struct {
-	Name                    *IdentifierOrValueExpression
-	PartitionSchemeColumns  []*Identifier
+	Name                   *IdentifierOrValueExpression
+	PartitionSchemeColumns []*Identifier
 }
 
 func (*FileGroupOrPartitionScheme) node() {}
+
+// DropClusteredConstraintWaitAtLowPriorityLockOption represents a WAIT_AT_LOW_PRIORITY option.
+type DropClusteredConstraintWaitAtLowPriorityLockOption struct {
+	OptionKind string // Always "MaxDop" based on the expected output
+	Options    []LowPriorityLockWaitOption
+}
+
+func (*DropClusteredConstraintWaitAtLowPriorityLockOption) node()                          {}
+func (*DropClusteredConstraintWaitAtLowPriorityLockOption) dropClusteredConstraintOption() {}

ast/backup_statement.go

@@ -2,9 +2,16 @@ package ast
 
 // BackupDatabaseStatement represents a BACKUP DATABASE statement
 type BackupDatabaseStatement struct {
-	DatabaseName *IdentifierOrValueExpression
-	Devices      []*DeviceInfo
-	Options      []*BackupOption
+	Files          []*BackupRestoreFileInfo
+	DatabaseName   *IdentifierOrValueExpression
+	MirrorToClauses []*MirrorToClause
+	Devices        []*DeviceInfo
+	Options        []*BackupOption
+}
+
+// MirrorToClause represents a MIRROR TO clause in a BACKUP statement
+type MirrorToClause struct {
+	Devices []*DeviceInfo
 }
 
 func (s *BackupDatabaseStatement) statementNode() {}

ast/distinct_predicate.go

@@ -0,0 +1,11 @@
+package ast
+
+// DistinctPredicate represents an IS [NOT] DISTINCT FROM expression.
+type DistinctPredicate struct {
+	FirstExpression  ScalarExpression
+	SecondExpression ScalarExpression
+	IsNot            bool
+}
+
+func (d *DistinctPredicate) node()              {}
+func (d *DistinctPredicate) booleanExpression() {}

ast/merge_statement.go

@@ -11,6 +11,7 @@ func (s *MergeStatement) statement() {}
 // MergeSpecification represents the specification of a MERGE statement
 type MergeSpecification struct {
 	Target          TableReference    // The target table
+	TableAlias      *Identifier       // Alias for the USING clause table reference (e.g., AS src)
 	TableReference  TableReference    // The USING clause table reference
 	SearchCondition BooleanExpression // The ON clause condition (may be GraphMatchPredicate)
 	ActionClauses   []*MergeActionClause

ast/next_value_for_expression.go

@@ -0,0 +1,10 @@
+package ast
+
+// NextValueForExpression represents a NEXT VALUE FOR sequence expression.
+type NextValueForExpression struct {
+	SequenceName *SchemaObjectName
+	OverClause   *OverClause
+}
+
+func (n *NextValueForExpression) node()             {}
+func (n *NextValueForExpression) scalarExpression() {}