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Implement casting of MySQL ENUM types.
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Dimitri Fontaine
parent
e6d4c73c1b
commit
be0738d70a
@ -4,8 +4,39 @@
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(in-package :pgloader.mysql)
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;;;
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;;; Some functions to deal with ENUM types
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;;;
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(defun explode-mysql-enum (ctype)
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"Convert MySQL ENUM expression into a list of labels."
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;; from: "ENUM('small', 'medium', 'large')"
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;; to: ("small" "medium" "large")
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(mapcar (lambda (x) (string-trim "' )" x))
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(sq:split-sequence #\, ctype :start (position #\' ctype))))
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(defun get-enum-type-name (table-name column-name)
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"Return the Type Name we're going to use in PostgreSQL."
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(format nil "~a_~a" table-name column-name))
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(defun get-create-enum (table-name column-name ctype)
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"Return a PostgreSQL CREATE ENUM TYPE statement from MySQL enum column."
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(with-output-to-string (s)
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(format s "CREATE TYPE ~a AS ENUM (~{'~a'~^, ~});"
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(get-enum-type-name table-name column-name)
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(explode-mysql-enum ctype))))
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(defun cast-enum (table-name column-name type ctype typemod)
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"Cast MySQL inline ENUM type to using a PostgreSQL named type.
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The type naming is hardcoded to be table-name_column-name"
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(declare (ignore type ctype typemod))
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(format nil "~a_~a" table-name column-name))
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;;;
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;;; The default MySQL Type Casting Rules
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;;;
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(defparameter *default-cast-rules*
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'((:source (:type "int" :auto-increment t :typemod (< 10))
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`((:source (:type "int" :auto-increment t :typemod (< 10))
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:target (:type "serial"))
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(:source (:type "int" :auto-increment t :typemod (>= 10))
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@ -28,19 +59,30 @@
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(:source (:type "date" :default "0000-00-00")
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:target (:type "date" :drop-default t))
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(:source (:type "datetime") :target (:type "timestamptz")))
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(:source (:type "datetime")
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:target (:type "timestamptz"))
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(:source (:type "enum")
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:target (:type ,#'cast-enum)))
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"Data Type Casting rules to migrate from MySQL to PostgreSQL")
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(defvar *cast-rules* nil "Specific casting rules added in the command.")
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(defun parse-column-typemod (column-type)
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"Given int(7), returns the number 7."
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(let ((splits (sq:split-sequence-if (lambda (c) (member c '(#\( #\))))
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column-type
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:remove-empty-subseqs t)))
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(if (= 1 (length splits))
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nil
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(parse-integer (nth 1 splits)))))
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;;;
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;;; Handling typmod in the general case, don't apply to ENUM types
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;;;
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(defun parse-column-typemod (data-type column-type)
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"Given int(7), returns the number 7.
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Beware that some data-type are using a typmod looking definition for
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things that are not typmods at all: enum."
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(unless (string= "enum" data-type)
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(let ((splits (sq:split-sequence-if (lambda (c) (member c '(#\( #\))))
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column-type
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:remove-empty-subseqs t)))
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(if (= 1 (length splits))
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nil
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(parse-integer (nth 1 splits))))))
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(defun typemod-expr-matches-p (rule-typemod-expr typemod)
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"Check if an expression such as (< 10) matches given typemod."
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@ -60,14 +102,16 @@
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((:not-null rule-source-not-null) nil n-s-p)
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((:auto-increment rule-source-auto-increment) nil ai-s-p))
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rule-source
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(destructuring-bind (&key type
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(destructuring-bind (&key table-name
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column-name
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type
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ctype
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typemod
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default
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not-null
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auto-increment)
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source
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(declare (ignore ctype))
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(declare (ignore table-name column-name ctype))
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(when
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(and
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(string= type rule-source-type)
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@ -79,8 +123,11 @@
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(defun format-pgsql-type (source target using)
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"Returns a string suitable for a PostgreSQL type definition"
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(destructuring-bind (&key ((:type source-type))
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ctype
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(destructuring-bind (&key ((:table-name source-table-name))
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((:column-name source-column-name))
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((:type source-type))
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((:ctype source-ctype))
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((:typemod source-typemod))
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default
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not-null
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&allow-other-keys)
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@ -91,7 +138,11 @@
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target
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(format nil
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"~a~:[~; not null~]~:[~; default '~a'~]"
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type
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(typecase type
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(function (funcall type
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source-table-name source-column-name
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source-type source-ctype source-typemod))
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(t type))
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(and not-null (not drop-not-null))
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(and default (not drop-default))
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;; apply the transformation function to the default value
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@ -101,16 +152,20 @@
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;;
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;; prefer char(24) over just char, that is the column type over the
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;; data type.
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ctype)))
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source-ctype)))
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(defun apply-casting-rules (dtype ctype default nullable extra
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&optional (rules (append *cast-rules*
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*default-cast-rules*)))
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&key
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table-name column-name ; ENUM support
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(rules (append *cast-rules*
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*default-cast-rules*)))
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"Apply the given RULES to the MySQL SOURCE type definition"
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(let* ((typemod (parse-column-typemod ctype))
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(let* ((typemod (parse-column-typemod dtype ctype))
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(not-null (string-equal nullable "NO"))
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(auto-increment (string= "auto_increment" extra))
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(source (append (list :type dtype)
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(source (append (list :table-name table-name)
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(list :column-name column-name)
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(list :type dtype)
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(list :ctype ctype)
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(when typemod (list :typemod typemod))
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(list :default default)
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@ -133,13 +188,15 @@
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(apply-casting-rules dtype ctype default nullable extra)
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transform-fn))
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(defun cast (dtype ctype default nullable extra)
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(defun cast (table-name column-name dtype ctype default nullable extra)
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"Convert a MySQL datatype to a PostgreSQL datatype.
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DYTPE is the MySQL data_type and CTYPE the MySQL column_type, for example
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that would be int and int(7) or varchar and varchar(25)."
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(destructuring-bind (&key pgtype &allow-other-keys)
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(apply-casting-rules dtype ctype default nullable extra)
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(apply-casting-rules dtype ctype default nullable extra
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:table-name table-name
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:column-name column-name)
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pgtype))
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(defun transforms (columns)
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@ -184,11 +241,12 @@ that would be int and int(7) or varchar and varchar(25)."
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("c" "varchar" "varchar(25)" nil nil nil)
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("d" "tinyint" "tinyint(4)" "0" nil nil)
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("e" "datetime" "datetime" "0000-00-00 00:00:00" nil nil)
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("f" "date" "date" "0000-00-00" "NO" nil))))
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("f" "date" "date" "0000-00-00" "NO" nil)
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("g" "enum" "ENUM('a', 'b')" nil nil nil))))
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(loop
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for (name dtype ctype nullable default extra) in columns
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for pgtype = (cast dtype ctype nullable default extra)
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for pgtype = (cast "table" name dtype ctype nullable default extra)
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for fn in (transforms columns)
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do
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(format t "~a~14T~a~45T~:[~;using ~a~]~%" ctype pgtype fn fn))))
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(format t "~a~18T~a~45T~:[~;using ~a~]~%" ctype pgtype fn fn))))
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14
mysql.lisp
14
mysql.lisp
@ -72,13 +72,23 @@ order by table_name, ordinal_position" dbname)))
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;; free resources
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(cl-mysql:disconnect)))
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(defun get-create-type (table-name cols &key include-drop)
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"MySQL declares ENUM types inline, PostgreSQL wants explicit CREATE TYPE."
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(loop
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for (name dtype ctype default nullable extra) in cols
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when (string-equal "enum" dtype)
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collect (when include-drop
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(let ((type-name (get-enum-type-name table-name name)))
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(format nil "DROP TYPE IF EXISTS ~a;" type-name)))
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and collect (get-create-enum table-name name ctype)))
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(defun get-create-table (table-name cols)
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"Return a PostgreSQL CREATE TABLE statement from MySQL columns"
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(with-output-to-string (s)
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(format s "CREATE TABLE ~a ~%(~%" table-name)
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(loop
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for ((name dtype ctype default nullable extra) . last?) on cols
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for pg-coldef = (cast dtype ctype default nullable extra)
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for pg-coldef = (cast table-name name dtype ctype default nullable extra)
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do (format s " ~a ~22t ~a~:[~;,~]~%" name pg-coldef last?))
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(format s ");~%")))
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@ -90,7 +100,9 @@ order by table_name, ordinal_position" dbname)))
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"Return the list of CREATE TABLE statements to run against PostgreSQL"
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(loop
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for (table-name . cols) in all-columns
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for extra-types = (get-create-type table-name cols :include-drop include-drop)
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when include-drop collect (get-drop-table-if-exists table-name)
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when extra-types append extra-types
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collect (get-create-table table-name cols)))
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(defun pgsql-create-tables (dbname all-columns
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