load-schema: add GF, implement in SQLite client

mak08 · Dec 17, 2019 · f3825ca · f3825ca
1 parent 4190f60
commit f3825ca
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Showing 4 changed files with 48 additions and 10 deletions.
diff --git a/sql/sql-api.cl b/sql/sql-api.cl
@@ -1,7 +1,7 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Description    High-level SQL API
 ;;; Author         Michael Kappert 2013
-;;; Last Modified  <michael 2019-12-16 18:05:34>
+;;; Last Modified  <michael 2019-12-17 22:53:48>
 
 (in-package :sql)
 
@@ -111,7 +111,7 @@
 (defun update-schema (schema user-name &key (redeploy nil))
   (with-transaction ()
     (let* ((old-schema
-            (load-db-schema (schema-name schema))))
+            (load-schema *current-connection* (schema-name schema))))
 
       (cond
         ((null old-schema)

diff --git a/sql/sql-if.cl b/sql/sql-if.cl
@@ -1,7 +1,7 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Description  Low-level interface to the backend 
 ;;; Author         Michael 2014
-;;; Last Modified <michael 2019-12-15 12:49:42>
+;;; Last Modified <michael 2019-12-17 22:53:20>
 
 (in-package :sql)
 
@@ -48,5 +48,8 @@
                 (with-output-to-string (s)
                   (serialize-for-connection conn sql-statement s))))
 
+(defgeneric load-schema (connection name)
+  (:documentation "Load a schema definition from the DB"))
+
 ;;; EOF
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/sql/sql-package.cl b/sql/sql-package.cl
@@ -1,7 +1,7 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Description
 ;;; Author         Michael 2014
-;;; Last Modified <michael 2019-12-16 20:37:11>
+;;; Last Modified <michael 2019-12-17 23:10:15>
 
 (defpackage "SQL"
   (:use "COMMON-LISP"
@@ -13,7 +13,7 @@
   (:export
 
    ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-   ;; Database connection
+   ;; Backend integration
 
    ;; The following two macros are implemented and exported from backend packages:
    ;; with-open-connection ((conn &rest args &key &allow-other-keys) &body forms)
@@ -25,21 +25,32 @@
    ;; Select current connection
    with-connection
 
-   ;; SQL - basic interaction
+   ;; SQL - basic interaction.
+   ;; The backends define methods for their own connection class.
    sql-exec
    sql-query
    fetch
    serialize-for-connection
 
+   ;; Retrieving metadata from the DB
+   ;; The backends define methods for their own connection class.
+   load-schema
+
+
    ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
    ;; Embedded SQL - DDL Entities 
 
    ;; SQL Statement
-   sql-statement
 
+   ;; The parent struct of all SQL statements. Many DDL methods simply construct
+   ;; an SQL string and pass it it sql-exec%. Instead, an sql-statement should be
+   ;; constructed (a proper subtype may need to be defined first). This way,
+   ;; backends can customize the SQL string.
 
+   sql-statement
+
    ;; Database
-   database-create-statement ; paradoxically, this exists because of SQLite
+   database-create-statement
    database-create-statement-name
 
    database-drop-statement
@@ -49,7 +60,6 @@
    defschema
    %create-schema
    get-schema-by-name
-   load-db-schema
    find-db-schema
 
    schema
@@ -280,6 +290,9 @@
 
    ;; UUIDs
    create-uuid
+
+   ;; Parsing SQL
+   parse-table-definition
 
    ;; Internal use
    !{}

diff --git a/sqlite-client/sqlite-sql.cl b/sqlite-client/sqlite-sql.cl
@@ -1,7 +1,7 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Description   SQLite specific DDL statements 
 ;;; Author        Michael Kappert 2019
-;;; Last Modified <michael 2019-12-16 20:31:35>
+;;; Last Modified <michael 2019-12-17 23:29:13>
 
 (in-package :sqlite-client)
 
@@ -37,6 +37,28 @@
                            (format s "ATTACH '~a' AS ~a" schema-db schema-name)
                            (!{} conn (schema-create-statement-tables statement) s)))))))
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; Loading metadata
+;;;
+;;; SQLite stores CREATE TABLE statements in a special table SQLITE_MASTER.
+
+(defmethod load-schema ((connection sqlite-connection) (schema string))
+  (let ((schema-table
+         (cond ((string= schema "")
+                'sqlite_master)
+               (t
+                (make-symbol (format nil "~a.sqlite_master" schema))))))
+    (with-connection (connection)
+      (multiple-value-bind (columns rows)
+          (?select 'sql
+                   :from schema-table
+                   :where (?and (?= 'type "table")
+                                (?not (?= 'name "__schema"))))
+        (make-schema :name schema
+                     :tables (loop
+                                :for (sql) :in rows
+                                :collect (parse-table-definition sql)))))))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; DROP TABLE