Implement a new “snake_case” quoting rule.

In passing, add the identifiers case option to SQLite support, which makes
it easier to test here, and add a table named "TableName" to our local test
database.

Fix #631.

pgloader.asd

@@ -66,7 +66,7 @@
                        ;; PostgreSQL related utils
                        (:file "read-sql-files")
                        (:file "queries")
-                       (:file "quoting")
+                       (:file "quoting"     :depends-on ("utils"))
                        (:file "catalog"     :depends-on ("quoting"))
                        (:file "alter-table" :depends-on ("catalog"))
 

src/package.lisp

@@ -35,7 +35,8 @@
   (:export #:apply-identifier-case
            #:build-identifier
            #:quoted-p
-           #:ensure-unquoted))
+           #:ensure-unquoted
+           #:camelCase-to-colname))
 
 (defpackage #:pgloader.catalog
   (:use #:cl #:pgloader.params #:pgloader.quoting)

src/parsers/command-keywords.lisp

@@ -125,6 +125,7 @@
   (def-keyword-rule "keys")
   (def-keyword-rule "downcase")
   (def-keyword-rule "quote")
+  (def-keyword-rule "snake_case")
   (def-keyword-rule "identifiers")
   (def-keyword-rule "including")
   (def-keyword-rule "excluding")

src/parsers/command-options.lisp

@@ -160,7 +160,10 @@
 (defrule option-on-error-stop (and kw-on kw-error kw-stop)
   (:constant (cons :on-error-stop t)))
 
-(defrule option-identifiers-case (and (or kw-downcase kw-quote) kw-identifiers)
+(defrule option-identifiers-case (and (or kw-snake_case
+                                          kw-downcase
+                                          kw-quote)
+                                      kw-identifiers)
   (:lambda (id-case)
     (bind (((action _) id-case))
       (cons :identifier-case action))))

src/parsers/command-sqlite.lisp

@@ -31,7 +31,8 @@ load database
 			   option-index-names
                            option-reset-sequences
                            option-foreign-keys
-                           option-encoding))
+                           option-encoding
+                           option-identifiers-case))
 
 (defrule sqlite-options (and kw-with
                              (and sqlite-option (* (and comma sqlite-option))))
@@ -100,6 +101,7 @@ load database
             (*cast-rules*         ',casts)
             ,@(pgsql-connection-bindings pg-db-conn gucs)
             ,@(batch-control-bindings options)
+            ,@(identifier-case-binding options)
             (source-db      (with-stats-collection ("fetch" :section :pre)
                                 (expand (fetch-file ,sqlite-db-conn))))
             (source

src/utils/quoting.lisp

@@ -40,8 +40,8 @@
 
                 ;; in other cases follow user directive
                 (t *identifier-case*))))
-
     (ecase *identifier-case*
+      (:snake_case (camelCase-to-colname identifier))
       (:downcase   lowercase-identifier)
       (:quote      (format nil "~s"
                            (cl-ppcre:regex-replace-all "\"" identifier "\"\"")))
@@ -68,3 +68,23 @@
                                          (string part)
                                          (t      (princ-to-string part))))
              :when more? :collect sep))))
+
+;;;
+;;; Camel Case converter
+;;;
+(defun camelCase-to-colname (string)
+  "Transform input STRING into a suitable column name.
+    lahmanID        lahman_id
+    playerID        player_id
+    birthYear       birth_year"
+  (coerce
+   (loop
+      :for first := t :then nil
+      :for char :across string
+      :for previous-upper-p := nil :then char-upper-p
+      :for char-upper-p := (and (alpha-char-p char)
+                                (eq char (char-upcase char)))
+      :for new-word := (and (not first) char-upper-p (not previous-upper-p))
+      :when (and new-word (not (char= char #\_))) :collect #\_
+      :collect (char-downcase char))
+   'string))

src/utils/threads.lisp

@@ -23,6 +23,7 @@
                             ;; needed in create index specific kernels
                             (*pgsql-reserved-keywords* . ',*pgsql-reserved-keywords*)
                             (*preserve-index-names* . ,*preserve-index-names*)
+                            (*identifier-case*      . ,*identifier-case*)
 
                             ;; bindings updates for libs
                             ;; CFFI is used by the SQLite lib

src/utils/utils.lisp

@@ -3,25 +3,6 @@
 ;;;
 (in-package :pgloader.utils)
 
-;;;
-;;; Camel Case converter
-;;;
-(defun camelCase-to-colname (string)
-  "Transform input STRING into a suitable column name.
-    lahmanID        lahman_id
-    playerID        player_id
-    birthYear       birth_year"
-  (coerce
-   (loop
-      for first = t then nil
-      for char across string
-      for previous-upper-p = nil then char-upper-p
-      for char-upper-p = (eq char (char-upcase char))
-      for new-word = (and (not first) char-upper-p (not previous-upper-p))
-      when (and new-word (not (char= char #\_))) collect #\_
-      collect (char-downcase char))
-   'string))
-
 ;;;
 ;;; Unquote SQLite default values, might be useful elsewhere
 ;;;

test/sqlite.load

@@ -3,6 +3,7 @@ load database
      into postgresql:///pgloader
 
  -- with include drop, create tables, create indexes, reset sequences
+ with snake_case identifiers
 
   before load do
     $$ drop schema if exists sqlite cascade; $$,