psql: Show all query results by default

Previously, psql printed only the last result if a command string
returned multiple result sets.  Now it prints all of them.  The
previous behavior can be obtained by setting the psql variable
SHOW_ALL_RESULTS to off.

Author: Fabien COELHO <coelho@cri.ensmp.fr>
Reviewed-by: "Iwata, Aya" <iwata.aya@jp.fujitsu.com>
Reviewed-by: Daniel Verite <daniel@manitou-mail.org>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1904132231510.8961@lancre

contrib/pg_stat_statements/expected/pg_stat_statements.out

@@ -50,8 +50,28 @@ BEGIN \;
 SELECT 2.0 AS "float" \;
 SELECT 'world' AS "text" \;
 COMMIT;
+ float 
+-------
+   2.0
+(1 row)
+
+ text  
+-------
+ world
+(1 row)
+
 -- compound with empty statements and spurious leading spacing
 \;\;   SELECT 3 + 3 \;\;\;   SELECT ' ' || ' !' \;\;   SELECT 1 + 4 \;;
+ ?column? 
+----------
+        6
+(1 row)
+
+ ?column? 
+----------
+   !
+(1 row)
+
  ?column? 
 ----------
         5
@@ -61,6 +81,11 @@ COMMIT;
 SELECT 1 + 1 + 1 AS "add" \gset
 SELECT :add + 1 + 1 AS "add" \;
 SELECT :add + 1 + 1 AS "add" \gset
+ add 
+-----
+   5
+(1 row)
+
 -- set operator
 SELECT 1 AS i UNION SELECT 2 ORDER BY i;
  i 

doc/src/sgml/ref/psql-ref.sgml

@@ -127,18 +127,11 @@ echo '\x \\ SELECT * FROM foo;' | psql
        commands included in the string to divide it into multiple
        transactions.  (See <xref linkend="protocol-flow-multi-statement"/>
        for more details about how the server handles multi-query strings.)
-       Also, <application>psql</application> only prints the
-       result of the last <acronym>SQL</acronym> command in the string.
-       This is different from the behavior when the same string is read from
-       a file or fed to <application>psql</application>'s standard input,
-       because then <application>psql</application> sends
-       each <acronym>SQL</acronym> command separately.
       </para>
       <para>
-       Because of this behavior, putting more than one SQL command in a
-       single <option>-c</option> string often has unexpected results.
-       It's better to use repeated <option>-c</option> commands or feed
-       multiple commands to <application>psql</application>'s standard input,
+       If having several commands executed in one transaction is not desired, 
+       use repeated <option>-c</option> commands or feed multiple commands to
+       <application>psql</application>'s standard input,
        either using <application>echo</application> as illustrated above, or
        via a shell here-document, for example:
 <programlisting>
@@ -3527,10 +3520,6 @@ select 1\; select 2\; select 3;
         commands included in the string to divide it into multiple
         transactions.  (See <xref linkend="protocol-flow-multi-statement"/>
         for more details about how the server handles multi-query strings.)
-        <application>psql</application> prints only the last query result
-        it receives for each request; in this example, although all
-        three <command>SELECT</command>s are indeed executed, <application>psql</application>
-        only prints the <literal>3</literal>.
         </para>
         </listitem>
       </varlistentry>
@@ -4117,6 +4106,18 @@ bar
       </varlistentry>
 
       <varlistentry>
+        <term><varname>SHOW_ALL_RESULTS</varname></term>
+        <listitem>
+        <para>
+        When this variable is set to <literal>off</literal>, only the last
+        result of a combined query (<literal>\;</literal>) is shown instead of
+        all of them.  The default is <literal>on</literal>.  The off behavior
+        is for compatibility with older versions of psql.
+        </para>
+        </listitem>
+      </varlistentry>
+
+       <varlistentry>
         <term><varname>SHOW_CONTEXT</varname></term>
         <listitem>
         <para>

src/bin/psql/help.c

@@ -410,6 +410,8 @@ helpVariables(unsigned short int pager)
 	fprintf(output, _("  SERVER_VERSION_NAME\n"
 					  "  SERVER_VERSION_NUM\n"
 					  "    server's version (in short string or numeric format)\n"));
+	fprintf(output, _("  SHOW_ALL_RESULTS\n"
+					  "    show all results of a combined query (\\;) instead of only the last\n"));
 	fprintf(output, _("  SHOW_CONTEXT\n"
 					  "    controls display of message context fields [never, errors, always]\n"));
 	fprintf(output, _("  SINGLELINE\n"

src/bin/psql/settings.h

@@ -148,6 +148,7 @@ typedef struct _psqlSettings
 	const char *prompt2;
 	const char *prompt3;
 	PGVerbosity verbosity;		/* current error verbosity level */
+	bool		show_all_results;
 	PGContextVisibility show_context;	/* current context display level */
 } PsqlSettings;
 

src/bin/psql/startup.c

@@ -196,6 +196,7 @@ main(int argc, char *argv[])
 	SetVariable(pset.vars, "PROMPT1", DEFAULT_PROMPT1);
 	SetVariable(pset.vars, "PROMPT2", DEFAULT_PROMPT2);
 	SetVariable(pset.vars, "PROMPT3", DEFAULT_PROMPT3);
+	SetVariableBool(pset.vars, "SHOW_ALL_RESULTS");
 
 	parse_psql_options(argc, argv, &options);
 
@@ -1130,6 +1131,12 @@ verbosity_hook(const char *newval)
 	return true;
 }
 
+static bool
+show_all_results_hook(const char *newval)
+{
+	return ParseVariableBool(newval, "SHOW_ALL_RESULTS", &pset.show_all_results);
+}
+
 static char *
 show_context_substitute_hook(char *newval)
 {
@@ -1231,6 +1238,9 @@ EstablishVariableSpace(void)
 	SetVariableHooks(pset.vars, "VERBOSITY",
 					 verbosity_substitute_hook,
 					 verbosity_hook);
+	SetVariableHooks(pset.vars, "SHOW_ALL_RESULTS",
+					 bool_substitute_hook,
+					 show_all_results_hook);
 	SetVariableHooks(pset.vars, "SHOW_CONTEXT",
 					 show_context_substitute_hook,
 					 show_context_hook);

src/bin/psql/tab-complete.c

@@ -4122,7 +4122,7 @@ psql_completion(const char *text, int start, int end)
 		matches = complete_from_variables(text, "", "", false);
 	else if (TailMatchesCS("\\set", MatchAny))
 	{
-		if (TailMatchesCS("AUTOCOMMIT|ON_ERROR_STOP|QUIET|"
+		if (TailMatchesCS("AUTOCOMMIT|ON_ERROR_STOP|QUIET|SHOW_ALL_RESULTS|"
 						  "SINGLELINE|SINGLESTEP"))
 			COMPLETE_WITH_CS("on", "off");
 		else if (TailMatchesCS("COMP_KEYWORD_CASE"))

src/test/regress/expected/copyselect.out

@@ -126,7 +126,7 @@ copy (select 1) to stdout\; select 1/0;	-- row, then error
 ERROR:  division by zero
 select 1/0\; copy (select 1) to stdout; -- error only
 ERROR:  division by zero
-copy (select 1) to stdout\; copy (select 2) to stdout\; select 0\; select 3; -- 1 2 3
+copy (select 1) to stdout\; copy (select 2) to stdout\; select 3\; select 4; -- 1 2 3 4
 1
 2
  ?column? 
@@ -134,8 +134,18 @@ copy (select 1) to stdout\; copy (select 2) to stdout\; select 0\; select 3; --
         3
 (1 row)
 
+ ?column? 
+----------
+        4
+(1 row)
+
 create table test3 (c int);
-select 0\; copy test3 from stdin\; copy test3 from stdin\; select 1; -- 1
+select 0\; copy test3 from stdin\; copy test3 from stdin\; select 1; -- 0 1
+ ?column? 
+----------
+        0
+(1 row)
+
  ?column? 
 ----------
         1

src/test/regress/expected/psql.out

@@ -5078,3 +5078,96 @@ List of access methods
  hash  | uuid_ops        | uuid                 | uuid                  |      2 | uuid_hash_extended
 (5 rows)
 
+--
+-- combined queries
+--
+CREATE FUNCTION warn(msg TEXT) RETURNS BOOLEAN LANGUAGE plpgsql
+AS $$
+  BEGIN RAISE NOTICE 'warn %', msg ; RETURN TRUE ; END
+$$;
+-- show both
+SELECT 1 AS one \; SELECT warn('1.5') \; SELECT 2 AS two ;
+ one 
+-----
+   1
+(1 row)
+
+NOTICE:  warn 1.5
+CONTEXT:  PL/pgSQL function warn(text) line 2 at RAISE
+ warn 
+------
+ t
+(1 row)
+
+ two 
+-----
+   2
+(1 row)
+
+-- \gset applies to last query only
+SELECT 3 AS three \; SELECT warn('3.5') \; SELECT 4 AS four \gset
+ three 
+-------
+     3
+(1 row)
+
+NOTICE:  warn 3.5
+CONTEXT:  PL/pgSQL function warn(text) line 2 at RAISE
+ warn 
+------
+ t
+(1 row)
+
+\echo :three :four
+:three 4
+-- syntax error stops all processing
+SELECT 5 \; SELECT 6 + \; SELECT warn('6.5') \; SELECT 7 ;
+ERROR:  syntax error at or near ";"
+LINE 1: SELECT 5 ; SELECT 6 + ; SELECT warn('6.5') ; SELECT 7 ;
+                              ^
+-- with aborted transaction, stop on first error
+BEGIN \; SELECT 8 AS eight \; SELECT 9/0 AS nine \; ROLLBACK \; SELECT 10 AS ten ;
+ eight 
+-------
+     8
+(1 row)
+
+ERROR:  division by zero
+-- close previously aborted transaction
+ROLLBACK;
+-- misc SQL commands
+-- (non SELECT output is sent to stderr, thus is not shown in expected results)
+SELECT 'ok' AS "begin" \;
+CREATE TABLE psql_comics(s TEXT) \;
+INSERT INTO psql_comics VALUES ('Calvin'), ('hobbes') \;
+COPY psql_comics FROM STDIN \;
+UPDATE psql_comics SET s = 'Hobbes' WHERE s = 'hobbes' \;
+DELETE FROM psql_comics WHERE s = 'Moe' \;
+COPY psql_comics TO STDOUT \;
+TRUNCATE psql_comics \;
+DROP TABLE psql_comics \;
+SELECT 'ok' AS "done" ;
+ begin 
+-------
+ ok
+(1 row)
+
+Calvin
+Susie
+Hobbes
+ done 
+------
+ ok
+(1 row)
+
+\set SHOW_ALL_RESULTS off
+SELECT 1 AS one \; SELECT warn('1.5') \; SELECT 2 AS two ;
+NOTICE:  warn 1.5
+CONTEXT:  PL/pgSQL function warn(text) line 2 at RAISE
+ two 
+-----
+   2
+(1 row)
+
+\set SHOW_ALL_RESULTS on
+DROP FUNCTION warn(TEXT);

src/test/regress/expected/transactions.out

@@ -900,8 +900,18 @@ DROP TABLE abc;
 -- tests rely on the fact that psql will not break SQL commands apart at a
 -- backslash-quoted semicolon, but will send them as one Query.
 create temp table i_table (f1 int);
--- psql will show only the last result in a multi-statement Query
+-- psql will show all results of a multi-statement Query
 SELECT 1\; SELECT 2\; SELECT 3;
+ ?column? 
+----------
+        1
+(1 row)
+
+ ?column? 
+----------
+        2
+(1 row)
+
  ?column? 
 ----------
         3
@@ -916,6 +926,12 @@ insert into i_table values(1)\; select * from i_table;
 
 -- 1/0 error will cause rolling back the whole implicit transaction
 insert into i_table values(2)\; select * from i_table\; select 1/0;
+ f1 
+----
+  1
+  2
+(2 rows)
+
 ERROR:  division by zero
 select * from i_table;
  f1 
@@ -935,8 +951,18 @@ WARNING:  there is no transaction in progress
 -- begin converts implicit transaction into a regular one that
 -- can extend past the end of the Query
 select 1\; begin\; insert into i_table values(5);
+ ?column? 
+----------
+        1
+(1 row)
+
 commit;
 select 1\; begin\; insert into i_table values(6);
+ ?column? 
+----------
+        1
+(1 row)
+
 rollback;
 -- commit in implicit-transaction state commits but issues a warning.
 insert into i_table values(7)\; commit\; insert into i_table values(8)\; select 1/0;
@@ -963,22 +989,52 @@ rollback;  -- we are not in a transaction at this point
 WARNING:  there is no transaction in progress
 -- implicit transaction block is still a transaction block, for e.g. VACUUM
 SELECT 1\; VACUUM;
+ ?column? 
+----------
+        1
+(1 row)
+
 ERROR:  VACUUM cannot run inside a transaction block
 SELECT 1\; COMMIT\; VACUUM;
 WARNING:  there is no transaction in progress
+ ?column? 
+----------
+        1
+(1 row)
+
 ERROR:  VACUUM cannot run inside a transaction block
 -- we disallow savepoint-related commands in implicit-transaction state
 SELECT 1\; SAVEPOINT sp;
+ ?column? 
+----------
+        1
+(1 row)
+
 ERROR:  SAVEPOINT can only be used in transaction blocks
 SELECT 1\; COMMIT\; SAVEPOINT sp;
 WARNING:  there is no transaction in progress
+ ?column? 
+----------
+        1
+(1 row)
+
 ERROR:  SAVEPOINT can only be used in transaction blocks
 ROLLBACK TO SAVEPOINT sp\; SELECT 2;
 ERROR:  ROLLBACK TO SAVEPOINT can only be used in transaction blocks
 SELECT 2\; RELEASE SAVEPOINT sp\; SELECT 3;
+ ?column? 
+----------
+        2
+(1 row)
+
 ERROR:  RELEASE SAVEPOINT can only be used in transaction blocks
 -- but this is OK, because the BEGIN converts it to a regular xact
 SELECT 1\; BEGIN\; SAVEPOINT sp\; ROLLBACK TO SAVEPOINT sp\; COMMIT;
+ ?column? 
+----------
+        1
+(1 row)
+
 -- Tests for AND CHAIN in implicit transaction blocks
 SET TRANSACTION READ ONLY\; COMMIT AND CHAIN;  -- error
 ERROR:  COMMIT AND CHAIN can only be used in transaction blocks

src/test/regress/sql/copyselect.sql

@@ -84,10 +84,10 @@ drop table test1;
 -- psql handling of COPY in multi-command strings
 copy (select 1) to stdout\; select 1/0;	-- row, then error
 select 1/0\; copy (select 1) to stdout; -- error only
-copy (select 1) to stdout\; copy (select 2) to stdout\; select 0\; select 3; -- 1 2 3
+copy (select 1) to stdout\; copy (select 2) to stdout\; select 3\; select 4; -- 1 2 3 4
 
 create table test3 (c int);
-select 0\; copy test3 from stdin\; copy test3 from stdin\; select 1; -- 1
+select 0\; copy test3 from stdin\; copy test3 from stdin\; select 1; -- 0 1
 1
 \.
 2

src/test/regress/sql/psql.sql

@@ -1228,3 +1228,41 @@ drop role regress_partitioning_role;
 \dAo * pg_catalog.jsonb_path_ops
 \dAp+ btree float_ops
 \dAp * pg_catalog.uuid_ops
+
+--
+-- combined queries
+--
+CREATE FUNCTION warn(msg TEXT) RETURNS BOOLEAN LANGUAGE plpgsql
+AS $$
+  BEGIN RAISE NOTICE 'warn %', msg ; RETURN TRUE ; END
+$$;
+-- show both
+SELECT 1 AS one \; SELECT warn('1.5') \; SELECT 2 AS two ;
+-- \gset applies to last query only
+SELECT 3 AS three \; SELECT warn('3.5') \; SELECT 4 AS four \gset
+\echo :three :four
+-- syntax error stops all processing
+SELECT 5 \; SELECT 6 + \; SELECT warn('6.5') \; SELECT 7 ;
+-- with aborted transaction, stop on first error
+BEGIN \; SELECT 8 AS eight \; SELECT 9/0 AS nine \; ROLLBACK \; SELECT 10 AS ten ;
+-- close previously aborted transaction
+ROLLBACK;
+-- misc SQL commands
+-- (non SELECT output is sent to stderr, thus is not shown in expected results)
+SELECT 'ok' AS "begin" \;
+CREATE TABLE psql_comics(s TEXT) \;
+INSERT INTO psql_comics VALUES ('Calvin'), ('hobbes') \;
+COPY psql_comics FROM STDIN \;
+UPDATE psql_comics SET s = 'Hobbes' WHERE s = 'hobbes' \;
+DELETE FROM psql_comics WHERE s = 'Moe' \;
+COPY psql_comics TO STDOUT \;
+TRUNCATE psql_comics \;
+DROP TABLE psql_comics \;
+SELECT 'ok' AS "done" ;
+Moe
+Susie
+\.
+\set SHOW_ALL_RESULTS off
+SELECT 1 AS one \; SELECT warn('1.5') \; SELECT 2 AS two ;
+\set SHOW_ALL_RESULTS on
+DROP FUNCTION warn(TEXT);

src/test/regress/sql/transactions.sql

@@ -504,7 +504,7 @@ DROP TABLE abc;
 
 create temp table i_table (f1 int);
 
--- psql will show only the last result in a multi-statement Query
+-- psql will show all results of a multi-statement Query
 SELECT 1\; SELECT 2\; SELECT 3;
 
 -- this implicitly commits: