Thread: ECPG insert into table name as a variable
I was doing testing on an app and wanted to make a table name a variable
so I can change it via a config file (instead of re-compile/relink).
like so: EXEC SQL INSERT INTO :tname (host, point, type, cooked) VALUES (:host, :name, :type, :cooked);
This fails ecpg preprocess with "ERROR: syntax error at or near ":tname" whereas if the table
name is specified statically it works fine, like: EXEC SQL INSERT INTO tname (host, point, type, cooked) VALUES (:host,
:name,:type, :cooked);
When I tried hacking the resulting C code (as a test exercise) like:
{ ECPGdo(__LINE__, 0, 1, NULL, "insert into ? ( host , point , type , cooked ) values ( ? , ? , ? , ? )",
ECPGt_char,&(tname),(long)0,(long)1,1*sizeof(char),ECPGt_char,&(host),(long)0,(long)1,1*sizeof(char),
ECPGt_NO_INDICATOR,NULL , 0L, 0L, 0L, ECPGt_char,&(name),(long)0,(long)1,1*sizeof(char), ECPGt_NO_INDICATOR, NULL , 0L,
0L,0L, ECPGt_char,&(type),(long)1,(long)1,1*sizeof(char), ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
ECPGt_char,&(cooked),(long)1,(long)1,1*sizeof(char),ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
ECPGt_char,(starttime),(long)30,(long)1,30*sizeof(char),ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
ECPGt_char,(interval),(long)30,(long)1,30*sizeof(char),ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
it got all funny and didn't work very well (well ok it didn't work at all): pg.pgc:129 SQL Insert failed: Invalid
statementname (null) in line 124.
So, I was wondering am I just missing some obvious way to do this, or
is this not supported at all?
Thanks
--
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Ryan Mooney ryan@pcslink.com
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On Tue, Sep 23, 2003 at 11:12:07AM -1000, Ryan Mooney wrote:
> EXEC SQL INSERT INTO :tname (host, point, type, cooked) VALUES (:host, :name, :type, :cooked);
This is not possible as of now, but of course could be implemented.
> When I tried hacking the resulting C code (as a test exercise) like:
>
> { ECPGdo(__LINE__, 0, 1, NULL, "insert into ? ( host , point , type , cooked ) values ( ? , ? , ? , ? )",
> ECPGt_char,&(tname),(long)0,(long)1,1*sizeof(char),
You need to specify the indicator here as this:
ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
> ECPGt_char,&(host),(long)0,(long)1,1*sizeof(char),
> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
> ECPGt_char,&(name),(long)0,(long)1,1*sizeof(char),
> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
> ECPGt_char,&(type),(long)1,(long)1,1*sizeof(char),
> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
> ECPGt_char,&(cooked),(long)1,(long)1,1*sizeof(char),
> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
> ECPGt_char,(starttime),(long)30,(long)1,30*sizeof(char),
> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
> ECPGt_char,(interval),(long)30,(long)1,30*sizeof(char),
> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,
>
> it got all funny and didn't work very well (well ok it didn't work at all):
> pg.pgc:129 SQL Insert failed: Invalid statement name (null) in line 124.
>
> So, I was wondering am I just missing some obvious way to do this, or
> is this not supported at all?
So far it is not, sorry.
Michael
--
Michael Meskes
Email: Michael at Fam-Meskes dot De
ICQ: 179140304, AIM/Yahoo: michaelmeskes, Jabber: meskes@jabber.org
Go SF 49ers! Go Rhein Fire! Use Debian GNU/Linux! Use PostgreSQL!
No, not like that. But it'd be nice...
No do what you want consider something along the lines of:
snprintf(l_cmd, sizeof(l_cmd), "ALTER TABLE %s ADD COLUMN %s%d FLOAT4 NULL", tables[t].table,
tables[t].column,n);EXEC SQL EXECUTE IMMEDIATE :l_cmd;
or, more useful:
else snprintf(l_cmd, sizeof(l_cmd), "SELECT src.shot, %s FROM %s src WHERE %s IS NOT NULL AND channel = %d",
attribute,table, nullattr, channel);
EXEC_SQL_BEGIN;
/* declare & open */ EXEC SQL PREPARE lofsdb_SelectAttr_stmt FROM :l_cmd; EXEC SQL DECLARE lofsdb_SelectAttr_cur
CURSORFOR lofsdb_SelectAttr_stmt; EXEC SQL OPEN lofsdb_SelectAttr_cur;
and then just treat the CURSOR as normal... But for INSERTs the first
EXECUTE IMMEDIATE will do.
L.
Ryan Mooney writes:> > > I was doing testing on an app and wanted to make a table name a variable> so I can change it
viaa config file (instead of re-compile/relink).> > like so:> EXEC SQL INSERT INTO :tname (host, point, type, cooked)
VALUES(:host, :name, :type, :cooked);> > This fails ecpg preprocess with "ERROR: syntax error at or near ":tname"
whereasif the table > name is specified statically it works fine, like:> EXEC SQL INSERT INTO tname (host, point,
type,cooked) VALUES (:host, :name, :type, :cooked);> > When I tried hacking the resulting C code (as a test exercise)
like:>> { ECPGdo(__LINE__, 0, 1, NULL, "insert into ? ( host , point , type , cooked ) values ( ? , ? , ? , ?
)",> ECPGt_char,&(tname),(long)0,(long)1,1*sizeof(char),> ECPGt_char,&(host),(long)0,(long)1,1*sizeof(char),>
ECPGt_NO_INDICATOR,NULL , 0L, 0L, 0L,> ECPGt_char,&(name),(long)0,(long)1,1*sizeof(char),> ECPGt_NO_INDICATOR, NULL
,0L, 0L, 0L,> ECPGt_char,&(type),(long)1,(long)1,1*sizeof(char),> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,>
ECPGt_char,&(cooked),(long)1,(long)1,1*sizeof(char),> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,>
ECPGt_char,(starttime),(long)30,(long)1,30*sizeof(char),> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,>
ECPGt_char,(interval),(long)30,(long)1,30*sizeof(char),> ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L,> > it got all funny
anddidn't work very well (well ok it didn't work at all):> pg.pgc:129 SQL Insert failed: Invalid statement name
(null)in line 124.> > So, I was wondering am I just missing some obvious way to do this, or> is this not supported at
all?>> Thanks> > > -- > >-=-=-=-=-=-=-<>-=-=-=-=-=-<>-=-=-=-=-=-<>-=-=-=-=-=-<>-=-=-=-=-=-=-<> Ryan Mooney
ryan@pcslink.com > <-=-=-=-=-=-=-><-=-=-=-=-=-><-=-=-=-=-=-><-=-=-=-=-=-><-=-=-=-=-=-=->