Age Owner Branch data TLA Line data Source code
1 : : /*
2 : : * contrib/spi/insert_username.c
3 : : *
4 : : * insert user name in response to a trigger
5 : : * usage: insert_username (column_name)
6 : : */
7 : : #include "postgres.h"
8 : :
9 : : #include "access/htup_details.h"
10 : : #include "catalog/pg_type.h"
11 : : #include "commands/trigger.h"
12 : : #include "executor/spi.h"
13 : : #include "miscadmin.h"
14 : : #include "utils/builtins.h"
15 : : #include "utils/rel.h"
16 : :
164 tgl@sss.pgh.pa.us 17 :UBC 0 : PG_MODULE_MAGIC_EXT(
18 : : .name = "insert_username",
19 : : .version = PG_VERSION
20 : : );
21 : :
9056 22 : 0 : PG_FUNCTION_INFO_V1(insert_username);
23 : :
24 : : Datum
9231 25 : 0 : insert_username(PG_FUNCTION_ARGS)
26 : : {
27 : 0 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
28 : : Trigger *trigger; /* to get trigger name */
29 : : int nargs; /* # of arguments */
30 : : Datum newval; /* new value of column */
31 : : bool newnull; /* null flag */
32 : : char **args; /* arguments */
33 : : char *relname; /* triggered relation name */
34 : : Relation rel; /* triggered relation */
10186 vadim4o@yahoo.com 35 : 0 : HeapTuple rettuple = NULL;
36 : : TupleDesc tupdesc; /* tuple description */
37 : : int attnum;
38 : :
39 : : /* sanity checks from autoinc.c */
9231 tgl@sss.pgh.pa.us 40 [ # # # # ]: 0 : if (!CALLED_AS_TRIGGER(fcinfo))
41 : : /* internal error */
42 [ # # ]: 0 : elog(ERROR, "insert_username: not fired by trigger manager");
5447 43 [ # # ]: 0 : if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
44 : : /* internal error */
45 [ # # ]: 0 : elog(ERROR, "insert_username: must be fired for row");
46 [ # # ]: 0 : if (!TRIGGER_FIRED_BEFORE(trigdata->tg_event))
47 : : /* internal error */
10105 bruce@momjian.us 48 [ # # ]: 0 : elog(ERROR, "insert_username: must be fired before event");
49 : :
9231 tgl@sss.pgh.pa.us 50 [ # # ]: 0 : if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
51 : 0 : rettuple = trigdata->tg_trigtuple;
52 [ # # ]: 0 : else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
53 : 0 : rettuple = trigdata->tg_newtuple;
54 : : else
55 : : /* internal error */
6792 bruce@momjian.us 56 [ # # ]: 0 : elog(ERROR, "insert_username: cannot process DELETE events");
57 : :
9231 tgl@sss.pgh.pa.us 58 : 0 : rel = trigdata->tg_relation;
10186 vadim4o@yahoo.com 59 : 0 : relname = SPI_getrelname(rel);
60 : :
9231 tgl@sss.pgh.pa.us 61 : 0 : trigger = trigdata->tg_trigger;
62 : :
10186 vadim4o@yahoo.com 63 : 0 : nargs = trigger->tgnargs;
64 [ # # ]: 0 : if (nargs != 1)
65 : : /* internal error */
10105 bruce@momjian.us 66 [ # # ]: 0 : elog(ERROR, "insert_username (%s): one argument was expected", relname);
67 : :
10186 vadim4o@yahoo.com 68 : 0 : args = trigger->tgargs;
69 : 0 : tupdesc = rel->rd_att;
70 : :
10054 bruce@momjian.us 71 : 0 : attnum = SPI_fnumber(tupdesc, args[0]);
72 : :
3224 tgl@sss.pgh.pa.us 73 [ # # ]: 0 : if (attnum <= 0)
8080 74 [ # # ]: 0 : ereport(ERROR,
75 : : (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
76 : : errmsg("\"%s\" has no attribute \"%s\"", relname, args[0])));
77 : :
10054 bruce@momjian.us 78 [ # # ]: 0 : if (SPI_gettypeid(tupdesc, attnum) != TEXTOID)
8080 tgl@sss.pgh.pa.us 79 [ # # ]: 0 : ereport(ERROR,
80 : : (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
81 : : errmsg("attribute \"%s\" of \"%s\" must be type TEXT",
82 : : args[0], relname)));
83 : :
84 : : /* create fields containing name */
3773 andrew@dunslane.net 85 : 0 : newval = CStringGetTextDatum(GetUserNameFromId(GetUserId(), false));
3224 tgl@sss.pgh.pa.us 86 : 0 : newnull = false;
87 : :
88 : : /* construct new tuple */
89 : 0 : rettuple = heap_modify_tuple_by_cols(rettuple, tupdesc,
90 : : 1, &attnum, &newval, &newnull);
91 : :
10054 bruce@momjian.us 92 : 0 : pfree(relname);
93 : :
9231 tgl@sss.pgh.pa.us 94 : 0 : return PointerGetDatum(rettuple);
95 : : }
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