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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:19:15 +0000 |
commit | 6eb9c5a5657d1fe77b55cc261450f3538d35a94d (patch) | |
tree | 657d8194422a5daccecfd42d654b8a245ef7b4c8 /contrib/spi/insert_username.c | |
parent | Initial commit. (diff) | |
download | postgresql-13-upstream.tar.xz postgresql-13-upstream.zip |
Adding upstream version 13.4.upstream/13.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'contrib/spi/insert_username.c')
-rw-r--r-- | contrib/spi/insert_username.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/contrib/spi/insert_username.c b/contrib/spi/insert_username.c new file mode 100644 index 0000000..a2e1747 --- /dev/null +++ b/contrib/spi/insert_username.c @@ -0,0 +1,92 @@ +/* + * contrib/spi/insert_username.c + * + * insert user name in response to a trigger + * usage: insert_username (column_name) + */ +#include "postgres.h" + +#include "access/htup_details.h" +#include "catalog/pg_type.h" +#include "commands/trigger.h" +#include "executor/spi.h" +#include "miscadmin.h" +#include "utils/builtins.h" +#include "utils/rel.h" + +PG_MODULE_MAGIC; + +PG_FUNCTION_INFO_V1(insert_username); + +Datum +insert_username(PG_FUNCTION_ARGS) +{ + TriggerData *trigdata = (TriggerData *) fcinfo->context; + Trigger *trigger; /* to get trigger name */ + int nargs; /* # of arguments */ + Datum newval; /* new value of column */ + bool newnull; /* null flag */ + char **args; /* arguments */ + char *relname; /* triggered relation name */ + Relation rel; /* triggered relation */ + HeapTuple rettuple = NULL; + TupleDesc tupdesc; /* tuple description */ + int attnum; + + /* sanity checks from autoinc.c */ + if (!CALLED_AS_TRIGGER(fcinfo)) + /* internal error */ + elog(ERROR, "insert_username: not fired by trigger manager"); + if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) + /* internal error */ + elog(ERROR, "insert_username: must be fired for row"); + if (!TRIGGER_FIRED_BEFORE(trigdata->tg_event)) + /* internal error */ + elog(ERROR, "insert_username: must be fired before event"); + + if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) + rettuple = trigdata->tg_trigtuple; + else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) + rettuple = trigdata->tg_newtuple; + else + /* internal error */ + elog(ERROR, "insert_username: cannot process DELETE events"); + + rel = trigdata->tg_relation; + relname = SPI_getrelname(rel); + + trigger = trigdata->tg_trigger; + + nargs = trigger->tgnargs; + if (nargs != 1) + /* internal error */ + elog(ERROR, "insert_username (%s): one argument was expected", relname); + + args = trigger->tgargs; + tupdesc = rel->rd_att; + + attnum = SPI_fnumber(tupdesc, args[0]); + + if (attnum <= 0) + ereport(ERROR, + (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION), + errmsg("\"%s\" has no attribute \"%s\"", relname, args[0]))); + + if (SPI_gettypeid(tupdesc, attnum) != TEXTOID) + ereport(ERROR, + (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION), + errmsg("attribute \"%s\" of \"%s\" must be type TEXT", + args[0], relname))); + + /* create fields containing name */ + newval = CStringGetTextDatum(GetUserNameFromId(GetUserId(), false)); + newnull = false; + + /* construct new tuple */ + rettuple = heap_modify_tuple_by_cols(rettuple, tupdesc, + 1, &attnum, &newval, &newnull); + + pfree(relname); + + return PointerGetDatum(rettuple); +} |