Allow ALTER VIEW command to rename the column in the view.

ALTER TABLE RENAME COLUMN command always can be used to rename the column
in the view, but it's reasonable to add that syntax to ALTER VIEW too.

Author: Fujii Masao
Reviewed-by: Ibrar Ahmed, Yu Kimura
Discussion: https://postgr.es/m/CAHGQGwHoQMD3b-MqTLcp1MgdhCpOKU7QNRwjFooT4_d+ti5v6g@mail.gmail.com

diff --git a/doc/src/sgml/ref/alter_view.sgml b/doc/src/sgml/ref/alter_view.sgml
index 2e9edc1975833c997d3ad7be3e3bb6b3439cc983..b66160bfb8955ffe0060a02eaa55b75a01e377e5 100644 (file)
--- a/doc/src/sgml/ref/alter_view.sgml
+++ b/doc/src/sgml/ref/alter_view.sgml
@@ -24,6 +24,7 @@ PostgreSQL documentation
 ALTER VIEW [ IF EXISTS ] name ALTER [ COLUMN ] column_name SET DEFAULT expression
 ALTER VIEW [ IF EXISTS ] name ALTER [ COLUMN ] column_name DROP DEFAULT
 ALTER VIEW [ IF EXISTS ] name OWNER TO { new_owner | CURRENT_USER | SESSION_USER }
+ALTER VIEW [ IF EXISTS ] name RENAME [ COLUMN ] column_name TO new_column_name
 ALTER VIEW [ IF EXISTS ] name RENAME TO new_name
 ALTER VIEW [ IF EXISTS ] name SET SCHEMA new_schema
 ALTER VIEW [ IF EXISTS ] name SET ( view_option_name [= view_option_value] [, ... ] )
@@ -65,6 +66,24 @@ ALTER VIEW [ IF EXISTS ] name RESET
     
    
 
+   
+    column_name
+    
+     
+      Name of an existing column.
+     
+    
+   
+
+   
+    new_column_name
+    
+     
+      New name for an existing column.
+     
+    
+   
+
    
     IF EXISTS
     

diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c
index 9fa433a975405a88563dcbd4c92ca0a6c2c5d28d..9b5148093b6e84ee894c32131596093078bfb81a 100644 (file)
--- a/src/backend/commands/view.c
+++ b/src/backend/commands/view.c
@@ -276,7 +276,8 @@ checkViewTupleDesc(TupleDesc newdesc, TupleDesc olddesc)
                    (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
                     errmsg("cannot change name of view column \"%s\" to \"%s\"",
                            NameStr(oldattr->attname),
-                           NameStr(newattr->attname))));
+                           NameStr(newattr->attname)),
+                    errhint("Use ALTER VIEW ... RENAME COLUMN ... to change name of view column instead.")));
        /* XXX would it be safe to allow atttypmod to change?  Not sure */
        if (newattr->atttypid != oldattr->atttypid ||
            newattr->atttypmod != oldattr->atttypmod)

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2f7bd662e8a8a91d80165252ba6d07fbc13ddc0e..c5086846decc0b90e346df917386dff0b306c585 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -8777,6 +8777,28 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
                    n->missing_ok = true;
                    $$ = (Node *)n;
                }
+           | ALTER VIEW qualified_name RENAME opt_column name TO name
+               {
+                   RenameStmt *n = makeNode(RenameStmt);
+                   n->renameType = OBJECT_COLUMN;
+                   n->relationType = OBJECT_VIEW;
+                   n->relation = $3;
+                   n->subname = $6;
+                   n->newname = $8;
+                   n->missing_ok = false;
+                   $$ = (Node *)n;
+               }
+           | ALTER VIEW IF_P EXISTS qualified_name RENAME opt_column name TO name
+               {
+                   RenameStmt *n = makeNode(RenameStmt);
+                   n->renameType = OBJECT_COLUMN;
+                   n->relationType = OBJECT_VIEW;
+                   n->relation = $5;
+                   n->subname = $8;
+                   n->newname = $10;
+                   n->missing_ok = true;
+                   $$ = (Node *)n;
+               }
            | ALTER MATERIALIZED VIEW qualified_name RENAME opt_column name TO name
                {
                    RenameStmt *n = makeNode(RenameStmt);

diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 1578568a91cf96ab10d448d82e1801ca4d6d2034..172e00b46ef3f3167bc2503f7c6471b96cec78d0 100644 (file)
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1797,8 +1797,20 @@ psql_completion(const char *text, int start, int end)
        COMPLETE_WITH("TO");
    /* ALTER VIEW  */
    else if (Matches("ALTER", "VIEW", MatchAny))
-       COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME TO",
+       COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME",
                      "SET SCHEMA");
+   /* ALTER VIEW xxx RENAME */
+   else if (Matches("ALTER", "VIEW", MatchAny, "RENAME"))
+       COMPLETE_WITH_ATTR(prev2_wd, " UNION SELECT 'COLUMN' UNION SELECT 'TO'");
+   else if (Matches("ALTER", "VIEW", MatchAny, "ALTER|RENAME", "COLUMN"))
+       COMPLETE_WITH_ATTR(prev3_wd, "");
+   /* ALTER VIEW xxx RENAME yyy */
+   else if (Matches("ALTER", "VIEW", MatchAny, "RENAME", MatchAnyExcept("TO")))
+       COMPLETE_WITH("TO");
+   /* ALTER VIEW xxx RENAME COLUMN yyy */
+   else if (Matches("ALTER", "VIEW", MatchAny, "RENAME", "COLUMN", MatchAnyExcept("TO")))
+       COMPLETE_WITH("TO");
+
    /* ALTER MATERIALIZED VIEW  */
    else if (Matches("ALTER", "MATERIALIZED", "VIEW", MatchAny))
        COMPLETE_WITH("ALTER COLUMN", "CLUSTER ON", "DEPENDS ON EXTENSION",

diff --git a/src/test/regress/expected/create_view.out b/src/test/regress/expected/create_view.out
index 2fd36ca9a1465c17da401161c68076b478c9f773..9a92629fd79f40e5bead640d921c8e53f4f8d617 100644 (file)
--- a/src/test/regress/expected/create_view.out
+++ b/src/test/regress/expected/create_view.out
@@ -64,6 +64,7 @@ ERROR:  cannot drop columns from view
 CREATE OR REPLACE VIEW viewtest AS
    SELECT 1, * FROM viewtest_tbl;
 ERROR:  cannot change name of view column "a" to "?column?"
+HINT:  Use ALTER VIEW ... RENAME COLUMN ... to change name of view column instead.
 -- should fail
 CREATE OR REPLACE VIEW viewtest AS
    SELECT a, b::numeric FROM viewtest_tbl;
@@ -1189,6 +1190,29 @@ select pg_get_viewdef('vv1', true);
       CROSS JOIN tt6) j(aa, bb, cc_1, cc, dd);
 (1 row)
 
+create view v4 as select * from v1;
+alter view v1 rename column a to x;
+select pg_get_viewdef('v1', true);
+                  pg_get_viewdef                   
+---------------------------------------------------
+  SELECT tt2.b,                                   +
+     tt3.c,                                       +
+     tt2.a AS x,                                  +
+     tt3.ax                                       +
+    FROM tt2                                      +
+      JOIN tt3 tt3(ax, b, c, c_1, e) USING (b, c);
+(1 row)
+
+select pg_get_viewdef('v4', true);
+ pg_get_viewdef 
+----------------
+  SELECT v1.b, +
+     v1.c,     +
+     v1.x AS a,+
+     v1.ax     +
+    FROM v1;
+(1 row)
+
 -- Unnamed FULL JOIN USING is lots of fun too
 create table tt7 (x int, xx int, y int);
 alter table tt7 drop column xx;
@@ -1782,7 +1806,7 @@ drop cascades to view aliased_view_2
 drop cascades to view aliased_view_3
 drop cascades to view aliased_view_4
 DROP SCHEMA testviewschm2 CASCADE;
-NOTICE:  drop cascades to 63 other objects
+NOTICE:  drop cascades to 64 other objects
 DETAIL:  drop cascades to table t1
 drop cascades to view temporal1
 drop cascades to view temporal2
@@ -1818,6 +1842,7 @@ drop cascades to view v3
 drop cascades to table tt5
 drop cascades to table tt6
 drop cascades to view vv1
+drop cascades to view v4
 drop cascades to table tt7
 drop cascades to table tt8
 drop cascades to view vv2

diff --git a/src/test/regress/sql/create_view.sql b/src/test/regress/sql/create_view.sql
index 8c0f45cc5268e846e5b99b909222fb6848ba5d57..be5d90727a9fa41e8145b53e7a6b1ef6fa404c8a 100644 (file)
--- a/src/test/regress/sql/create_view.sql
+++ b/src/test/regress/sql/create_view.sql
@@ -391,6 +391,12 @@ select pg_get_viewdef('vv1', true);
 alter table tt5 drop column c;
 select pg_get_viewdef('vv1', true);
 
+create view v4 as select * from v1;
+alter view v1 rename column a to x;
+select pg_get_viewdef('v1', true);
+select pg_get_viewdef('v4', true);
+
+
 -- Unnamed FULL JOIN USING is lots of fun too
 
 create table tt7 (x int, xx int, y int);