Fix MySQL Enum parsing.

We use a CSV parser for the MySQL enum values, but the quote escaping wasn't
properly setup: MySQL quotes ENUM values with a single-quote (') and uses
two of them ('') for escaping single-quotes when found in the ENUM value
itself.

Fixes #597.

src/pgsql/pgsql-ddl.lisp

@@ -26,7 +26,9 @@
     ((:enum :set)
      (format stream "CREATE TYPE ~a AS ENUM (~{'~a'~^, ~});"
              (sqltype-name sqltype)
-             (sqltype-extra sqltype)))))
+             (mapcar (lambda (value)
+                       (cl-ppcre:regex-replace-all "'" value "''"))
+                     (sqltype-extra sqltype))))))
 
 (defmethod format-drop-sql ((sqltype sqltype) &key (stream nil) cascade if-exists)
   (format stream "DROP TYPE~:[~; IF EXISTS~] ~a~@[ CASCADE~];"

src/sources/mysql/mysql-cast-rules.lisp

@@ -157,7 +157,7 @@
   "Convert MySQL ENUM expression into a list of labels."
   (cl-ppcre:register-groups-bind (list)
       ("(?i)(?:ENUM|SET)\\s*\\((.*)\\)" ctype)
-    (first (cl-csv:read-csv list :separator #\, :quote #\' :escape "\\"))))
+    (first (cl-csv:read-csv list :separator #\, :quote #\' :escape "''"))))
 
 (defmethod cast ((col mysql-column))
   "Return the PostgreSQL type definition from given MySQL column definition."