CREATE TABLE LIKE INCLUDING TRIGGERS

foreign key associated internal trigger won't being copied to new table.  source
table trigger associated comment will copied to new table, if INCLUDING COMMENTS
is specified.
Currently not support CREATE FOREIGN TABLE LIKE. (maybe we should).

discussion: https://postgr.es/m/CACJufxHJAr2FjbeB6ghg_-N5dxX5JVnjKSLOUxOyt4TeaAWQkg@mail.gmail.com
commitfest: https://commitfest.postgresql.org/patch/6087

Author: jianhe-fun

doc/src/sgml/ref/create_table.sgml

@@ -88,7 +88,7 @@ class="parameter">referential_action</replaceable> ] [ ON UPDATE <replaceable cl
 
 <phrase>and <replaceable class="parameter">like_option</replaceable> is:</phrase>
 
-{ INCLUDING | EXCLUDING } { COMMENTS | COMPRESSION | CONSTRAINTS | DEFAULTS | GENERATED | IDENTITY | INDEXES | STATISTICS | STORAGE | ALL }
+{ INCLUDING | EXCLUDING } { COMMENTS | COMPRESSION | CONSTRAINTS | DEFAULTS | GENERATED | IDENTITY | INDEXES | STATISTICS | STORAGE | TRIGGERS | ALL }
 
 <phrase>and <replaceable class="parameter">partition_bound_spec</replaceable> is:</phrase>
 
@@ -672,7 +672,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
         <term><literal>INCLUDING COMMENTS</literal></term>
         <listitem>
          <para>
-          Comments for the copied columns, constraints, and indexes will be
+          Comments for the copied columns, constraints, indexes and triggers will be
           copied.  The default behavior is to exclude comments, resulting in
           the copied columns and constraints in the new table having no
           comments.
@@ -776,6 +776,15 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
         </listitem>
        </varlistentry>
 
+       <varlistentry id="sql-createtable-parms-like-opt-triggers">
+        <term><literal>INCLUDING TRIGGERS</literal></term>
+        <listitem>
+         <para>
+          Any non-internal triggers on the original table will be created on the new table.
+         </para>
+        </listitem>
+       </varlistentry>
+
        <varlistentry id="sql-createtable-parms-like-opt-all">
         <term><literal>INCLUDING ALL</literal></term>
         <listitem>

src/backend/catalog/index.c

@@ -2040,6 +2040,7 @@ index_constraint_create(Relation heapRelation,
 		trigger->initdeferred = initdeferred;
 		trigger->constrrel = NULL;
 		trigger->transformed = true;
+		trigger->trigcomment = NULL;
 
 		(void) CreateTrigger(trigger, NULL, RelationGetRelid(heapRelation),
 							 InvalidOid, conOid, indexRelationId, InvalidOid,

src/backend/commands/tablecmds.c

@@ -13826,6 +13826,7 @@ CreateFKCheckTrigger(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint,
 	fk_trigger->deferrable = fkconstraint->deferrable;
 	fk_trigger->initdeferred = fkconstraint->initdeferred;
 	fk_trigger->constrrel = NULL;
+	fk_trigger->trigcomment = NULL;
 	fk_trigger->transformed = true;
 
 	trigAddress = CreateTrigger(fk_trigger, NULL, myRelOid, refRelOid,
@@ -13872,6 +13873,7 @@ createForeignKeyActionTriggers(Oid myRelOid, Oid refRelOid, Constraint *fkconstr
 	fk_trigger->whenClause = NULL;
 	fk_trigger->transitionRels = NIL;
 	fk_trigger->constrrel = NULL;
+	fk_trigger->trigcomment = NULL;
 	fk_trigger->transformed = true;
 
 	switch (fkconstraint->fk_del_action)
@@ -13933,6 +13935,7 @@ createForeignKeyActionTriggers(Oid myRelOid, Oid refRelOid, Constraint *fkconstr
 	fk_trigger->whenClause = NULL;
 	fk_trigger->transitionRels = NIL;
 	fk_trigger->constrrel = NULL;
+	fk_trigger->trigcomment = NULL;
 	fk_trigger->transformed = true;
 
 	switch (fkconstraint->fk_upd_action)
@@ -20865,6 +20868,7 @@ CloneRowTriggersToPartition(Relation parent, Relation partition)
 		trigStmt->deferrable = trigForm->tgdeferrable;
 		trigStmt->initdeferred = trigForm->tginitdeferred;
 		trigStmt->constrrel = NULL; /* passed separately */
+		trigStmt->trigcomment = NULL;
 		trigStmt->transformed = true; /* whenClause alerady transformed */
 
 		CreateTriggerFiringOn(trigStmt, NULL, RelationGetRelid(partition),

src/backend/commands/trigger.c

@@ -30,6 +30,7 @@
 #include "catalog/pg_proc.h"
 #include "catalog/pg_trigger.h"
 #include "catalog/pg_type.h"
+#include "commands/comment.h"
 #include "commands/trigger.h"
 #include "executor/executor.h"
 #include "miscadmin.h"
@@ -1122,6 +1123,11 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 	/* Keep lock on target rel until end of xact */
 	table_close(rel, NoLock);
 
+	/* Add any requested comment */
+	if (stmt->trigcomment != NULL)
+		CreateComments(trigoid, TriggerRelationId, 0,
+					   stmt->trigcomment);
+
 	return myself;
 }
 

src/backend/parser/gram.y

@@ -783,7 +783,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	TABLE TABLES TABLESAMPLE TABLESPACE TARGET TEMP TEMPLATE TEMPORARY TEXT_P THEN
 	TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSFORM
-	TREAT TRIGGER TRIM TRUE_P
+	TREAT TRIGGER TRIGGERS TRIM TRUE_P
 	TRUNCATE TRUSTED TYPE_P TYPES_P
 
 	UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
@@ -4243,6 +4243,7 @@ TableLikeOption:
 				| INDEXES			{ $$ = CREATE_TABLE_LIKE_INDEXES; }
 				| STATISTICS		{ $$ = CREATE_TABLE_LIKE_STATISTICS; }
 				| STORAGE			{ $$ = CREATE_TABLE_LIKE_STORAGE; }
+				| TRIGGERS			{ $$ = CREATE_TABLE_LIKE_TRIGGERS; }
 				| ALL				{ $$ = CREATE_TABLE_LIKE_ALL; }
 		;
 
@@ -6097,6 +6098,7 @@ CreateTrigStmt:
 					n->deferrable = false;
 					n->initdeferred = false;
 					n->constrrel = NULL;
+					n->trigcomment = NULL;
 					n->transformed = false;
 					$$ = (Node *) n;
 				}
@@ -6148,6 +6150,7 @@ CreateTrigStmt:
 								   &n->deferrable, &n->initdeferred, &dummy,
 								   NULL, NULL, yyscanner);
 					n->constrrel = $10;
+					n->trigcomment = NULL;
 					n->transformed = false;
 					$$ = (Node *) n;
 				}
@@ -18116,6 +18119,7 @@ unreserved_keyword:
 			| TRANSACTION
 			| TRANSFORM
 			| TRIGGER
+			| TRIGGERS
 			| TRUNCATE
 			| TRUSTED
 			| TYPE_P
@@ -18765,6 +18769,7 @@ bare_label_keyword:
 			| TRANSFORM
 			| TREAT
 			| TRIGGER
+			| TRIGGERS
 			| TRIM
 			| TRUE_P
 			| TRUNCATE