Prioritize renames before create and alter

Renames should go first, otherwise it could not be possible to add a new column with
the name which was just renamed to something. Eg. SRC:x->DST:y, Create DST:x.
Otherwise we can not run 'Create DST:x', because schema still have 'x' column.

Author: Eugen Konkov

lib/SQL/Translator/Diff.pm

@@ -292,13 +292,17 @@ sub produce_diff_sql {
           ()
         }
 
+      # Renames should go first, otherwise it could not be possible to add a new column with
+      # the name which was just renamed to something. Eg. SRC:x->DST:y, Create DST:x.
+      # Otherwise we can not run 'Create DST:x', because schema still have 'x' column.
+
       } qw/rename_table
           alter_drop_constraint
           alter_drop_index
           drop_field
+          rename_field
           add_field
           alter_field
-          rename_field
           alter_create_index
           alter_create_constraint
           alter_table/),

lib/SQL/Translator/Producer/PostgreSQL.pm

@@ -1188,9 +1188,9 @@ sub batch_alter_table {
   # now add everything else
   push @sql, batch_alter_table_statements(
     $diff_hash, $options, qw(
+      rename_field
       add_field
       alter_field
-      rename_field
       alter_create_index
       alter_create_constraint
       alter_table

lib/SQL/Translator/Utils.pm

@@ -394,9 +394,9 @@ sub batch_alter_table_statements {
     alter_drop_constraint
     alter_drop_index
     drop_field
+    rename_field
     add_field
     alter_field
-    rename_field
     alter_create_index
     alter_create_constraint
     alter_table

t/30sqlt-new-diff-mysql.t

@@ -72,6 +72,8 @@ ALTER TABLE person DROP INDEX u_name;
 
 ALTER TABLE employee DROP COLUMN job_title;
 
+ALTER TABLE person CHANGE COLUMN description physical_description text NULL;
+
 ALTER TABLE new_name ADD COLUMN new_field integer NULL;
 
 ALTER TABLE person ADD COLUMN is_rock_star tinyint(4) NULL DEFAULT 1;
@@ -84,8 +86,6 @@ ALTER TABLE person CHANGE COLUMN age age integer(11) NULL DEFAULT 18;
 
 ALTER TABLE person CHANGE COLUMN iq iq integer(11) NULL DEFAULT 0;
 
-ALTER TABLE person CHANGE COLUMN description physical_description text NULL;
-
 ALTER TABLE person ADD UNIQUE INDEX unique_name (name);
 
 ALTER TABLE employee ADD CONSTRAINT FK5302D47D93FE702E_diff FOREIGN KEY (employee_id) REFERENCES person (person_id);
@@ -136,12 +136,12 @@ ALTER TABLE old_name RENAME TO new_name,
                      ADD COLUMN new_field integer NULL;
 
 ALTER TABLE person DROP CONSTRAINT UC_age_name,
+                   CHANGE COLUMN description physical_description text NULL,
                    ADD COLUMN is_rock_star tinyint(4) NULL DEFAULT 1,
                    CHANGE COLUMN person_id person_id integer(11) NOT NULL auto_increment,
                    CHANGE COLUMN name name varchar(20) NOT NULL,
                    CHANGE COLUMN age age integer(11) NULL DEFAULT 18,
                    CHANGE COLUMN iq iq integer(11) NULL DEFAULT 0,
-                   CHANGE COLUMN description physical_description text NULL,
                    ADD UNIQUE UC_person_id (person_id),
                    ADD UNIQUE UC_age_name (age, name),
                    ENGINE=InnoDB;
@@ -207,13 +207,13 @@ ALTER TABLE employee DROP FOREIGN KEY FK5302D47D93FE702E,
 
 ALTER TABLE person DROP CONSTRAINT UC_age_name,
                    DROP INDEX u_name,
+                   CHANGE COLUMN description physical_description text NULL,
                    ADD COLUMN is_rock_star tinyint(4) NULL DEFAULT 1,
                    ADD COLUMN value double(8, 2) NULL DEFAULT 0.00,
                    CHANGE COLUMN person_id person_id integer(11) NOT NULL auto_increment,
                    CHANGE COLUMN name name varchar(20) NOT NULL,
                    CHANGE COLUMN age age integer(11) NULL DEFAULT 18,
                    CHANGE COLUMN iq iq integer(11) NULL DEFAULT 0,
-                   CHANGE COLUMN description physical_description text NULL,
                    ADD UNIQUE INDEX unique_name (name),
                    ADD UNIQUE UC_person_id (person_id),
                    ADD UNIQUE UC_age_name (age, name),

t/30sqlt-new-diff-pgsql.t

@@ -83,6 +83,8 @@ ALTER TABLE "person" DROP CONSTRAINT "UC_age_name";
 
 DROP INDEX "u_name";
 
+ALTER TABLE "person" RENAME COLUMN "description" TO "physical_description";
+
 ALTER TABLE "person" ADD COLUMN "is_rock_star" smallint DEFAULT 1;
 
 ALTER TABLE "person" ALTER COLUMN "person_id" TYPE serial;
@@ -99,8 +101,6 @@ ALTER TABLE "person" ALTER COLUMN "nickname" SET NOT NULL;
 
 ALTER TABLE "person" ALTER COLUMN "nickname" TYPE character varying(24);
 
-ALTER TABLE "person" RENAME COLUMN "description" TO "physical_description";
-
 ALTER TABLE "person" ADD CONSTRAINT "unique_name" UNIQUE ("name");
 
 ALTER TABLE "person" ADD CONSTRAINT "UC_person_id" UNIQUE ("person_id");
@@ -151,6 +151,8 @@ ALTER TABLE new_name ADD COLUMN new_field integer;
 
 ALTER TABLE person DROP CONSTRAINT UC_age_name;
 
+ALTER TABLE person RENAME COLUMN description TO physical_description;
+
 ALTER TABLE person ADD COLUMN is_rock_star smallint DEFAULT 1;
 
 ALTER TABLE person ALTER COLUMN person_id TYPE serial;
@@ -167,8 +169,6 @@ ALTER TABLE person ALTER COLUMN nickname SET NOT NULL;
 
 ALTER TABLE person ALTER COLUMN nickname TYPE character varying(24);
 
-ALTER TABLE person RENAME COLUMN description TO physical_description;
-
 ALTER TABLE person ADD CONSTRAINT UC_person_id UNIQUE (person_id);
 
 ALTER TABLE person ADD CONSTRAINT UC_age_name UNIQUE (age, name);
@@ -190,10 +190,10 @@ eq_or_diff($out, <<'## END OF DIFF', "No differences found");
 
 ## END OF DIFF
 
-is shift @warns, q!SQL::Translator::Diff::schema_diff(): Renamed table can't find old table "not_exists" for renamed table!,
-  'Warning: old table not found';
 is shift @warns, q!SQL::Translator::Diff::schema_diff(): Renamed column can't find old column "old_name.not_exists" for renamed column!,
   'Warning: old column not found';
+is shift @warns, q!SQL::Translator::Diff::schema_diff(): Renamed table can't find old table "not_exists" for renamed table!,
+  'Warning: old table not found';
 
 
 sub diff_it {

t/30sqlt-new-diff-sqlite.t

@@ -63,14 +63,14 @@ DROP INDEX u_name;
 
 -- SQL::Translator::Producer::SQLite cant drop_field;
 
+-- SQL::Translator::Producer::SQLite cant rename_field;
+
 ALTER TABLE new_name ADD COLUMN new_field int;
 
 ALTER TABLE person ADD COLUMN is_rock_star tinyint(4) DEFAULT 1;
 
 -- SQL::Translator::Producer::SQLite cant alter_field;
 
--- SQL::Translator::Producer::SQLite cant rename_field;
-
 CREATE UNIQUE INDEX unique_name ON person (name);
 
 CREATE UNIQUE INDEX UC_person_id ON person (person_id);