Fix typos

README.rst

@@ -510,7 +510,7 @@ Example of a correlated subquery in the `SELECT`
 Unions
 """"""
 
-Both ``UNION`` and ``UNION ALL`` are supported. ``UNION DISTINCT`` is synonomous with "UNION`` so |Brand| does not
+Both ``UNION`` and ``UNION ALL`` are supported. ``UNION DISTINCT`` is synonymous with "UNION`` so |Brand| does not
 provide a separate function for it.  Unions require that queries have the same number of ``SELECT`` clauses so
 trying to cast a unioned query to string will throw a ``SetOperationException`` if the column sizes are mismatched.
 

pypika/enums.py

@@ -139,7 +139,7 @@ class Dialects(Enum):
     ORACLE = "oracle"
     MSSQL = "mssql"
     MYSQL = "mysql"
-    POSTGRESQL = "postgressql"
+    POSTGRESQL = "postgresql"
     REDSHIFT = "redshift"
     SQLLITE = "sqllite"
     SNOWFLAKE = "snowflake"

pypika/queries.py

@@ -1564,8 +1564,8 @@ def on_field(self, *fields: Any) -> QueryBuilder:
 
         criterion = None
         for field in fields:
-            consituent = Field(field, table=self.query._from[0]) == Field(field, table=self.item)
-            criterion = consituent if criterion is None else criterion & consituent
+            constituent = Field(field, table=self.query._from[0]) == Field(field, table=self.item)
+            criterion = constituent if criterion is None else criterion & constituent
 
         self.query.do_join(JoinOn(self.item, self.how, criterion))
         return self.query