Add dialect flags for NOT VALID and VALIDATE CONSTRAINT

Author: achristmascarl

src/dialect/mod.rs

@@ -1060,6 +1060,20 @@ pub trait Dialect: Debug + Any {
     fn supports_space_separated_column_options(&self) -> bool {
         false
     }
+
+    /// Returns true if the dialect supports `ADD <table_constraint> [NOT VALID]` in `ALTER TABLE` statements.
+    ///
+    /// -[PostgreSQL](https://www.postgresql.org/docs/17/sql-altertable.html)
+    fn supports_constraint_not_validation(&self) -> bool {
+        false
+    }
+
+    /// Returns true if the dialect supports `VALIDATE CONSTRAINT <constraint_name>` in `ALTER TABLE` statements.
+    ///
+    /// -[PostgreSQL](https://www.postgresql.org/docs/17/sql-altertable.html)
+    fn supports_validate_constraint(&self) -> bool {
+        false
+    }
 }
 
 /// This represents the operators for which precedence must be defined

src/dialect/postgresql.rs

@@ -258,4 +258,12 @@ impl Dialect for PostgreSqlDialect {
     fn supports_set_names(&self) -> bool {
         true
     }
+
+    fn supports_constraint_not_validation(&self) -> bool {
+        true
+    }
+
+    fn supports_validate_constraint(&self) -> bool {
+        true
+    }
 }