Hi Pavel,
On Tue, Oct 16, 2012 at 6:59 AM, Pavel Stehule <[email protected]>
wrote:
> here is updated patch, I moved lot of code from lexer to command.com,
> and now more \gset doesn't disable other backslash commands on same
> line.
* lexer changes
IIUC, new function psql_scan_varlist_varname scans input and returns a
variable name or a comma at each call, and command.c handles the error
such as invalid # of variables. This new design seems better than old one.
However, IMHO the name psql_scan_varlist_varname sounds redundant and
unintuitive. I'd prefer psql_scan_slash_varlist, because it indicates
that that function is expected to be used for arguments of backslash
commands, like psql_scan_slash_command and psql_scan_slash_option.
Thoughts?
* multiple meta command
Now both of the command sequences
$ SELECT 1, 2 \gset var1, var2 \g foo.txt
$ SELECT 1, 2 \g foo.txt \gset var1, var2
set var1 and v2 to "1" and "2" respectively, and also write the result
into foo.txt. This would be what users expected.
* Duplication of variables
I found an issue we have not discussed. Currently \gset accepts same
variable names in the list, and stores last SELECT item in duplicated
variables. For instance,
$ SELECT 1, 2 \gset var, var
stores "2" into var. I think this behavior is acceptable, but it might
be worth mentioning in document.
* extra fixes
I fixed some minor issues below. Please see attached v10 patch for details.
* remove unused macro OT_VARLIST
* remove unnecessary #include directive for common.h
* fill comment within 80 columns
* indent short variable name with tab
* add regression test case for combination of \g and \gset
* bug on FETCH_COUNT = 1
When FETCH_COUNT is set to 1, and the number of rows returned is 1 too,
\gset shows extra "(1 row)". This would be a bug in
ExecQueryUsingCursor. Please see the last test case in regression test
psql_cmd.
I'll mark this patch as "waiting author".
Regards,
--
Shigeru HANADA
*** a/doc/src/sgml/ref/psql-ref.sgml
--- b/doc/src/sgml/ref/psql-ref.sgml
***************
*** 1483,1490 **** testdb=>
way. Use <command>\i</command> for that.) This means that
if the query ends with (or contains) a semicolon, it is
immediately executed. Otherwise it will merely wait in the
! query buffer; type semicolon or <literal>\g</> to send it, or
! <literal>\r</> to cancel.
</para>
<para>
--- 1483,1490 ----
way. Use <command>\i</command> for that.) This means that
if the query ends with (or contains) a semicolon, it is
immediately executed. Otherwise it will merely wait in the
! query buffer; type semicolon, <literal>\g</> or
! <literal>\gset</literal> to send it, or <literal>\r</> to cancel.
</para>
<para>
***************
*** 1617,1622 **** Tue Oct 26 21:40:57 CEST 1999
--- 1617,1644 ----
</varlistentry>
<varlistentry>
+ <term><literal>\gset</literal> <replaceable class="parameter">variable</replaceable> [ ,<replaceable class="parameter">variable</replaceable> ... ] </term>
+
+ <listitem>
+ <para>
+ Sends the current query input buffer to the server and stores the
+ query's output into corresponding <replaceable
+ class="parameter">variable</replaceable>. The preceding query must
+ return only one row, and the number of variables must be same as the
+ number of elements in <command>SELECT</command> list. If you don't
+ need any of items in <command>SELECT</command> list, you can omit
+ corresponding <replaceable class="parameter">variable</replaceable>.
+ Example:
+ <programlisting>
+ foo=> SELECT 'hello', 'wonderful', 'world!' \gset var1,,var3
+ foo=> \echo :var1 :var3
+ hello world!
+ </programlisting>
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
<term><literal>\h</literal> or <literal>\help</literal> <literal>[ <replaceable class="parameter">command</replaceable> ]</literal></term>
<listitem>
<para>
*** a/src/bin/psql/command.c
--- b/src/bin/psql/command.c
***************
*** 71,77 **** static void printSSLInfo(void);
static void checkWin32Codepage(void);
#endif
!
/*----------
* HandleSlashCmds:
--- 71,86 ----
static void checkWin32Codepage(void);
#endif
! /*
! * Possible states for simple state machine, that is used for
! * parsing target list - list of varnames separated by comma.
! */
! typedef enum
! {
! VARLIST_INITIAL,
! VARLIST_EXPECTED_COMMA,
! VARLIST_EXPECTED_COMMA_OR_IDENT
! } VarlistParserState;
/*----------
* HandleSlashCmds:
***************
*** 748,753 **** exec_command(const char *cmd,
--- 757,831 ----
status = PSQL_CMD_SEND;
}
+ /* \gset send query and store result */
+ else if (strcmp(cmd, "gset") == 0)
+ {
+ bool value_is_valid;
+ char *value;
+ VarlistParserState state = VARLIST_INITIAL;
+
+ /* expected valid target list */
+ success = true;
+
+ pset.gvars = NULL;
+ while ((value = psql_scan_varlist_varname(scan_state, &value_is_valid)))
+ {
+ if (value_is_valid && success)
+ {
+ if (strcmp(value, ",") == 0)
+ {
+ if (state == VARLIST_INITIAL ||
+ state == VARLIST_EXPECTED_COMMA_OR_IDENT)
+ pset.gvars = tglist_add(pset.gvars, NULL);
+ state = VARLIST_EXPECTED_COMMA_OR_IDENT;
+ }
+ else
+ {
+ if (state == VARLIST_INITIAL ||
+ state == VARLIST_EXPECTED_COMMA_OR_IDENT)
+ {
+ pset.gvars = tglist_add(pset.gvars, value);
+ state = VARLIST_EXPECTED_COMMA;
+ }
+ else
+ success = false;
+ }
+ }
+ else
+ {
+ success = false;
+ /* but continue, we would to read to eol */
+ }
+
+ free(value);
+ }
+
+ /* final check and target list completation */
+ if (pset.gvars != NULL)
+ {
+ if (success)
+ {
+ if (state == VARLIST_EXPECTED_COMMA_OR_IDENT && success)
+ pset.gvars = tglist_add(pset.gvars, NULL);
+ status = PSQL_CMD_SEND;
+ }
+ else
+ {
+ psql_error("\\%s: syntax error\n", cmd);
+ tglist_free(pset.gvars);
+ pset.gvars = NULL;
+ status = PSQL_CMD_NOSEND;
+
+ }
+ }
+ else
+ {
+ psql_error("\\%s: missing required argument\n", cmd);
+ success = false;
+ status = PSQL_CMD_NOSEND;
+ }
+ }
+
/* help */
else if (strcmp(cmd, "h") == 0 || strcmp(cmd, "help") == 0)
{
*** a/src/bin/psql/command.h
--- b/src/bin/psql/command.h
***************
*** 16,21 **** typedef enum _backslashResult
--- 16,22 ----
{
PSQL_CMD_UNKNOWN = 0, /* not done parsing yet (internal only) */
PSQL_CMD_SEND, /* query complete; send off */
+ PSQL_CMD_NOSEND, /* query complete, don't send */
PSQL_CMD_SKIP_LINE, /* keep building query */
PSQL_CMD_TERMINATE, /* quit program */
PSQL_CMD_NEWEDIT, /* query buffer was changed (e.g., via \e) */
*** a/src/bin/psql/common.c
--- b/src/bin/psql/common.c
***************
*** 816,821 **** PrintQueryResults(PGresult *results)
--- 816,919 ----
return success;
}
+ /*
+ * StoreQueryResult: store first row of result to selected variables
+ *
+ * Note: Utility function for use by SendQuery() only.
+ *
+ * Returns true if the query executed successfully, false otherwise.
+ */
+ static bool
+ StoreQueryResult(PGresult *result)
+ {
+ bool success;
+
+ switch (PQresultStatus(result))
+ {
+ case PGRES_TUPLES_OK:
+ {
+ int i;
+
+ if (PQntuples(result) < 1)
+ {
+ psql_error("no data found\n");
+ success = false;
+ }
+ else if (PQntuples(result) > 1)
+ {
+ psql_error("too many rows\n");
+ success = false;
+ }
+ else
+ {
+ TargetListData *iter = (TargetListData *) pset.gvars;
+
+ success = true;
+
+ for (i = 0; i < PQnfields(result); i++)
+ {
+ if (!iter)
+ {
+ psql_error("too few target variables\n");
+ success = false;
+ break;
+ }
+
+ if (iter->name)
+ {
+ if (!SetVariable(pset.vars, iter->name,
+ PQgetvalue(result, 0, i)))
+ {
+ psql_error("invalid variable name: \"%s\"\n",
+ iter->name);
+ success = false;
+ break;
+ }
+ }
+
+ iter = iter->next;
+ }
+
+ if (success && iter != NULL)
+ {
+ psql_error("too many target variables\n");
+ success = false;
+ }
+ }
+ }
+ break;
+
+ case PGRES_COMMAND_OK:
+ case PGRES_EMPTY_QUERY:
+ psql_error("no data found\n");
+ success = false;
+ break;
+
+ case PGRES_COPY_OUT:
+ case PGRES_COPY_IN:
+ psql_error("COPY is not supported by \\gset command\n");
+ success = false;
+ break;
+
+ case PGRES_BAD_RESPONSE:
+ case PGRES_NONFATAL_ERROR:
+ case PGRES_FATAL_ERROR:
+ success = false;
+ psql_error("bad response\n");
+ break;
+
+ default:
+ success = false;
+ psql_error("unexpected PQresultStatus: %d\n",
+ PQresultStatus(result));
+ break;
+ }
+
+ tglist_free(pset.gvars);
+ pset.gvars = NULL;
+
+ return success;
+ }
/*
* SendQuery: send the query string to the backend
***************
*** 943,949 **** SendQuery(const char *query)
/* but printing results isn't: */
if (OK && results)
! OK = PrintQueryResults(results);
}
else
{
--- 1041,1052 ----
/* but printing results isn't: */
if (OK && results)
! {
! if (pset.gvars)
! OK = StoreQueryResult(results);
! else
! OK = PrintQueryResults(results);
! }
}
else
{
***************
*** 1067,1072 **** ExecQueryUsingCursor(const char *query, double *elapsed_msec)
--- 1170,1177 ----
instr_time before,
after;
int flush_error;
+ bool initial_loop;
+ bool store_result = pset.gvars != NULL;
*elapsed_msec = 0;
***************
*** 1133,1138 **** ExecQueryUsingCursor(const char *query, double *elapsed_msec)
--- 1238,1246 ----
/* clear any pre-existing error indication on the output stream */
clearerr(pset.queryFout);
+ /* we would to allow store result to variables only once */
+ initial_loop = true;
+
for (;;)
{
if (pset.timing)
***************
*** 1182,1188 **** ExecQueryUsingCursor(const char *query, double *elapsed_msec)
did_pager = true;
}
! printQuery(results, &my_popt, pset.queryFout, pset.logfile);
PQclear(results);
--- 1290,1312 ----
did_pager = true;
}
! if (pset.gvars)
! {
! OK = StoreQueryResult(results);
! if (!OK)
! {
! flush_error = fflush(pset.queryFout);
! break;
! }
! }
! else if (store_result && !initial_loop && ntuples > 0)
! {
! psql_error("too many rows\n");
! flush_error = fflush(pset.queryFout);
! break;
! }
! else
! printQuery(results, &my_popt, pset.queryFout, pset.logfile);
PQclear(results);
***************
*** 1208,1213 **** ExecQueryUsingCursor(const char *query, double *elapsed_msec)
--- 1332,1339 ----
if (ntuples < pset.fetch_count || cancel_pressed || flush_error ||
ferror(pset.queryFout))
break;
+
+ initial_loop = false;
}
/* close \g argument file/pipe, restore old setting */
***************
*** 1658,1660 **** expand_tilde(char **filename)
--- 1784,1836 ----
return *filename;
}
+
+
+ /*
+ * Add name of internal variable to query target list
+ *
+ */
+ TargetList
+ tglist_add(TargetList tglist, const char *name)
+ {
+ TargetListData *tgf;
+
+ tgf = pg_malloc(sizeof(TargetListData));
+ tgf->name = name ? pg_strdup(name) : NULL;
+ tgf->next = NULL;
+
+ if (tglist)
+ {
+ TargetListData *iter = (TargetListData *) tglist;
+
+ while (iter->next)
+ iter = iter->next;
+
+ iter->next = tgf;
+
+ return tglist;
+ }
+ else
+ return (TargetList) tgf;
+ }
+
+ /*
+ * Release target list
+ *
+ */
+ void
+ tglist_free(TargetList tglist)
+ {
+ TargetListData *iter = (TargetListData *) tglist;
+
+ while (iter)
+ {
+ TargetListData *next = iter->next;
+
+ if (iter->name)
+ free(iter->name);
+
+ free(iter);
+ iter = next;
+ }
+ }
*** a/src/bin/psql/common.h
--- b/src/bin/psql/common.h
***************
*** 21,26 ****
--- 21,34 ----
#define atooid(x) ((Oid) strtoul((x), NULL, 10))
+ typedef struct _target_field
+ {
+ char *name;
+ struct _target_field *next;
+ } TargetListData;
+
+ typedef struct TargetListData *TargetList;
+
/*
* Safer versions of some standard C library functions. If an
* out-of-memory condition occurs, these functions will bail out
***************
*** 62,65 **** extern const char *session_username(void);
--- 70,76 ----
extern char *expand_tilde(char **filename);
+ extern TargetList tglist_add(TargetList tglist, const char *name);
+ extern void tglist_free(TargetList tglist);
+
#endif /* COMMON_H */
*** a/src/bin/psql/help.c
--- b/src/bin/psql/help.c
***************
*** 162,174 **** slashUsage(unsigned short int pager)
{
FILE *output;
! output = PageOutput(94, pager);
/* if you add/remove a line here, change the row count above */
fprintf(output, _("General\n"));
fprintf(output, _(" \\copyright show PostgreSQL usage and distribution terms\n"));
fprintf(output, _(" \\g [FILE] or ; execute query (and send results to file or |pipe)\n"));
fprintf(output, _(" \\h [NAME] help on syntax of SQL commands, * for all commands\n"));
fprintf(output, _(" \\q quit psql\n"));
fprintf(output, "\n");
--- 162,175 ----
{
FILE *output;
! output = PageOutput(95, pager);
/* if you add/remove a line here, change the row count above */
fprintf(output, _("General\n"));
fprintf(output, _(" \\copyright show PostgreSQL usage and distribution terms\n"));
fprintf(output, _(" \\g [FILE] or ; execute query (and send results to file or |pipe)\n"));
+ fprintf(output, _(" \\gset NAME [, NAME [..]] execute query and store result in internal variables\n"));
fprintf(output, _(" \\h [NAME] help on syntax of SQL commands, * for all commands\n"));
fprintf(output, _(" \\q quit psql\n"));
fprintf(output, "\n");
*** a/src/bin/psql/mainloop.c
--- b/src/bin/psql/mainloop.c
***************
*** 327,332 **** MainLoop(FILE *source)
--- 327,340 ----
/* flush any paren nesting info after forced send */
psql_scan_reset(scan_state);
}
+ else if (slashCmdStatus == PSQL_CMD_NOSEND)
+ {
+ resetPQExpBuffer(query_buf);
+ /* reset parsing state since we are rescanning whole line */
+ psql_scan_reset(scan_state);
+ line_saved_in_history = true;
+ success = false;
+ }
else if (slashCmdStatus == PSQL_CMD_NEWEDIT)
{
/* rescan query_buf as new input */
*** a/src/bin/psql/psqlscan.h
--- b/src/bin/psql/psqlscan.h
***************
*** 59,64 **** extern char *psql_scan_slash_option(PsqlScanState state,
--- 59,67 ----
char *quote,
bool semicolon);
+ extern char *psql_scan_varlist_varname(PsqlScanState state, bool *is_ok);
+
+
extern void psql_scan_slash_command_end(PsqlScanState state);
#endif /* PSQLSCAN_H */
*** a/src/bin/psql/psqlscan.l
--- b/src/bin/psql/psqlscan.l
***************
*** 167,172 **** static void escape_variable(bool as_ident);
--- 167,173 ----
* <xdolq> $foo$ quoted strings
* <xui> quoted identifier with Unicode escapes
* <xus> quoted string with Unicode escapes
+ * <xvl> comma separated list of varnames
*
* Note: we intentionally don't mimic the backend's <xeu> state; we have
* no need to distinguish it from <xe> state, and no good way to get out
***************
*** 183,188 **** static void escape_variable(bool as_ident);
--- 184,190 ----
%x xdolq
%x xui
%x xus
+ %x xvl
/* Additional exclusive states for psql only: lex backslash commands */
%x xslashcmd
%x xslashargstart
***************
*** 628,633 **** other .
--- 630,667 ----
ECHO;
}
+ <xvl>{
+
+ {identifier} {
+ ECHO;
+ return LEXRES_OK;
+ }
+
+ "," {
+ ECHO;
+ return LEXRES_OK;
+ }
+
+ "\\\\" {
+ return LEXRES_EOL;
+ }
+
+ "\\" {
+ yyless(0);
+ return LEXRES_EOL;
+ }
+
+ {horiz_space}+ { }
+
+ . |
+ \n {
+ ECHO;
+ return LEXRES_EOL;
+ }
+
+ }
+
+
{xufailed} {
/* throw back all but the initial u/U */
yyless(1);
***************
*** 1937,1939 **** escape_variable(bool as_ident)
--- 1971,2022 ----
*/
emit(yytext, yyleng);
}
+
+ /*
+ * psql_scan_varlist - scan variable list for \gset command
+ *
+ * Returns next variable name or comma from variable list. When returned
+ * string is not empty and out parameter is_ok is false, then this string
+ * contains unexpected character. Returns NULL, when EOL is detected.
+ */
+ char *
+ psql_scan_varlist_varname(PsqlScanState state, bool *is_ok)
+ {
+ PQExpBufferData mybuf;
+ int lexresult;
+
+ /* Must be scanning already */
+ psql_assert(state->scanbufhandle);
+
+ /* Build a local buffer */
+ initPQExpBuffer(&mybuf);
+
+ /* Set up static variables that will be used by yylex */
+ cur_state = state;
+ output_buf = &mybuf;
+
+ if (state->buffer_stack != NULL)
+ yy_switch_to_buffer(state->buffer_stack->buf);
+ else
+ yy_switch_to_buffer(state->scanbufhandle);
+
+ BEGIN(xvl);
+ lexresult = yylex();
+
+ if (lexresult == LEXRES_OK)
+ {
+ *is_ok = true;
+ }
+ else if (lexresult == LEXRES_EOL && mybuf.len == 0)
+ {
+ *is_ok = true;
+ termPQExpBuffer(&mybuf);
+ return NULL;
+ }
+ else
+ {
+ *is_ok = false;
+ }
+
+ return mybuf.data;
+ }
*** a/src/bin/psql/settings.h
--- b/src/bin/psql/settings.h
***************
*** 9,14 ****
--- 9,15 ----
#define SETTINGS_H
+ #include "common.h"
#include "variables.h"
#include "print.h"
***************
*** 73,78 **** typedef struct _psqlSettings
--- 74,80 ----
printQueryOpt popt;
char *gfname; /* one-shot file output argument for \g */
+ TargetList gvars; /* one-shot target list argument for \gset */
bool notty; /* stdin or stdout is not a tty (as determined
* on startup) */
*** a/src/bin/psql/tab-complete.c
--- b/src/bin/psql/tab-complete.c
***************
*** 856,862 **** psql_completion(char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dn", "\\do", "\\dp", "\\drds", "\\ds", "\\dS", "\\dt", "\\dT", "\\dv", "\\du",
"\\e", "\\echo", "\\ef", "\\encoding",
! "\\f", "\\g", "\\h", "\\help", "\\H", "\\i", "\\ir", "\\l",
"\\lo_import", "\\lo_export", "\\lo_list", "\\lo_unlink",
"\\o", "\\p", "\\password", "\\prompt", "\\pset", "\\q", "\\qecho", "\\r",
"\\set", "\\sf", "\\t", "\\T",
--- 856,862 ----
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dn", "\\do", "\\dp", "\\drds", "\\ds", "\\dS", "\\dt", "\\dT", "\\dv", "\\du",
"\\e", "\\echo", "\\ef", "\\encoding",
! "\\f", "\\g", "\\gset", "\\h", "\\help", "\\H", "\\i", "\\ir", "\\l",
"\\lo_import", "\\lo_export", "\\lo_list", "\\lo_unlink",
"\\o", "\\p", "\\password", "\\prompt", "\\pset", "\\q", "\\qecho", "\\r",
"\\set", "\\sf", "\\t", "\\T",
*** /dev/null
--- b/src/test/regress/expected/psql_cmd.out
***************
*** 0 ****
--- 1,64 ----
+ -- \gset
+ select 10, 20, 'Hello';
+ ?column? | ?column? | ?column?
+ ----------+----------+----------
+ 10 | 20 | Hello
+ (1 row)
+
+ \gset gset_test01, gset_test02, gset_test03
+ \echo :gset_test01 :gset_test02 :gset_test03
+ 10 20 Hello
+ select 10, 20, 'Hello World'
+ \gset gset_test01, gset_test02, gset_test03
+ \echo :gset_test01 :gset_test02 :gset_test03
+ 10 20 Hello World
+ \gset ,, -- error
+ \gset: syntax error
+ \gset , -- error
+ \gset: syntax error
+ \gset ,,, -- error
+ \gset: syntax error
+ \gset -- error
+ \gset: missing required argument
+ \gset gset_test04,,
+ \echo :gset_test04
+ 10
+ \gset ,,gset_test05
+ \echo :gset_test05
+ Hello World
+ \gset ,gset_test06 ,
+ \echo :gset_test06
+ 20
+ -- should to work with cursor too
+ \set FETCH_COUNT 1
+ select 'a', 'b', 'c'
+ \gset gset_test01, gset_test02, gset_test03
+ (1 row)
+
+ \echo :gset_test01 :gset_test02 :gset_test03
+ a b c
+ select 1,2 \gset x,y \\ \echo :x
+ (1 row)
+
+ 1
+ select 1,2 \gset x,y \echo :x \echo :y
+ (1 row)
+
+ 1
+ 2
+ select 1,2 \gset x,y \\ \g \echo :x :y
+ (1 row)
+
+ ?column? | ?column?
+ ----------+----------
+ 1 | 2
+ (1 row)
+
+ 1 2
+ select 1,2 \g \gset x,y \echo :x :y
+ ?column? | ?column?
+ ----------+----------
+ 1 | 2
+ (1 row)
+
+ 1 2
*** a/src/test/regress/parallel_schedule
--- b/src/test/regress/parallel_schedule
***************
*** 109,111 **** test: plancache limit plpgsql copy2 temp domain rangefuncs prepare without_oid c
--- 109,113 ----
# run stats by itself because its delay may be insufficient under heavy load
test: stats
+
+ test: psql_cmd
*** a/src/test/regress/serial_schedule
--- b/src/test/regress/serial_schedule
***************
*** 134,136 **** test: largeobject
--- 134,137 ----
test: with
test: xml
test: stats
+ test: psql_cmd
*** /dev/null
--- b/src/test/regress/sql/psql_cmd.sql
***************
*** 0 ****
--- 1,45 ----
+ -- \gset
+
+ select 10, 20, 'Hello';
+
+ \gset gset_test01, gset_test02, gset_test03
+
+ \echo :gset_test01 :gset_test02 :gset_test03
+
+ select 10, 20, 'Hello World'
+
+ \gset gset_test01, gset_test02, gset_test03
+
+ \echo :gset_test01 :gset_test02 :gset_test03
+
+ \gset ,, -- error
+ \gset , -- error
+ \gset ,,, -- error
+ \gset -- error
+
+ \gset gset_test04,,
+ \echo :gset_test04
+
+ \gset ,,gset_test05
+ \echo :gset_test05
+
+ \gset ,gset_test06 ,
+ \echo :gset_test06
+
+ -- should to work with cursor too
+ \set FETCH_COUNT 1
+
+ select 'a', 'b', 'c'
+
+ \gset gset_test01, gset_test02, gset_test03
+
+ \echo :gset_test01 :gset_test02 :gset_test03
+
+ select 1,2 \gset x,y \\ \echo :x
+
+ select 1,2 \gset x,y \echo :x \echo :y
+
+ select 1,2 \gset x,y \\ \g \echo :x :y
+
+ select 1,2 \g \gset x,y \echo :x :y
+
--
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