Fix dblink_build_sql_insert() and related functions to handle dropped

columns correctly.  In passing, get rid of some dead logic in the
underlying get_sql_insert() etc functions --- there is no caller that
will pass null value-arrays to them.

Per bug report from Robert Voinea.

diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index fba208df639bc58fc4d19b1a855c81b49b7155ce..916cfc79ac54a3a3875ec441d6b6f96acb086f2c 100644 (file)
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -8,7 +8,7 @@
  * Darko Prenosil <[email protected]>
  * Shridhar Daithankar <[email protected]>
  *
- * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.69.2.7 2010/06/15 16:22:33 tgl Exp $
+ * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.69.2.8 2010/06/15 19:04:28 tgl Exp $
  * Copyright (c) 2001-2008, PostgreSQL Global Development Group
  * ALL RIGHTS RESERVED;
  *
@@ -1805,7 +1805,7 @@ get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals
    appendStringInfo(&buf, ") VALUES(");
 
    /*
-    * remember attvals are 1 based
+    * Note: i is physical column number (counting from 0).
     */
    needComma = false;
    for (i = 0; i < natts; i++)
@@ -1816,12 +1816,9 @@ get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals
        if (needComma)
            appendStringInfo(&buf, ",");
 
-       if (tgt_pkattvals != NULL)
-           key = get_attnum_pk_pos(pkattnums, pknumatts, i);
-       else
-           key = -1;
+       key = get_attnum_pk_pos(pkattnums, pknumatts, i);
 
-       if (key > -1)
+       if (key >= 0)
            val = tgt_pkattvals[key] ? pstrdup(tgt_pkattvals[key]) : NULL;
        else
            val = SPI_getvalue(tuple, tupdesc, i + 1);
@@ -1866,10 +1863,6 @@ get_sql_delete(Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals
        appendStringInfoString(&buf,
           quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));
 
-       if (tgt_pkattvals == NULL)
-           /* internal error */
-           elog(ERROR, "target key array must not be NULL");
-
        if (tgt_pkattvals[i] != NULL)
            appendStringInfo(&buf, " = %s",
                             quote_literal_cstr(tgt_pkattvals[i]));
@@ -1909,6 +1902,9 @@ get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals
 
    appendStringInfo(&buf, "UPDATE %s SET ", relname);
 
+   /*
+    * Note: i is physical column number (counting from 0).
+    */
    needComma = false;
    for (i = 0; i < natts; i++)
    {
@@ -1921,12 +1917,9 @@ get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals
        appendStringInfo(&buf, "%s = ",
                      quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));
 
-       if (tgt_pkattvals != NULL)
-           key = get_attnum_pk_pos(pkattnums, pknumatts, i);
-       else
-           key = -1;
+       key = get_attnum_pk_pos(pkattnums, pknumatts, i);
 
-       if (key > -1)
+       if (key >= 0)
            val = tgt_pkattvals[key] ? pstrdup(tgt_pkattvals[key]) : NULL;
        else
            val = SPI_getvalue(tuple, tupdesc, i + 1);
@@ -1953,16 +1946,10 @@ get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals
        appendStringInfo(&buf, "%s",
           quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));
 
-       if (tgt_pkattvals != NULL)
-           val = tgt_pkattvals[i] ? pstrdup(tgt_pkattvals[i]) : NULL;
-       else
-           val = SPI_getvalue(tuple, tupdesc, pkattnum + 1);
+       val = tgt_pkattvals[i];
 
        if (val != NULL)
-       {
            appendStringInfo(&buf, " = %s", quote_literal_cstr(val));
-           pfree(val);
-       }
        else
            appendStringInfo(&buf, " IS NULL");
    }
@@ -2026,30 +2013,49 @@ get_tuple_of_interest(Relation rel, int *pkattnums, int pknumatts, char **src_pk
 {
    char       *relname;
    TupleDesc   tupdesc;
+   int         natts;
    StringInfoData buf;
    int         ret;
    HeapTuple   tuple;
    int         i;
 
+   /*
+    * Connect to SPI manager
+    */
+   if ((ret = SPI_connect()) < 0)
+       /* internal error */
+       elog(ERROR, "SPI connect failure - returned %d", ret);
+
    initStringInfo(&buf);
 
    /* get relation name including any needed schema prefix and quoting */
    relname = generate_relation_name(rel);
 
    tupdesc = rel->rd_att;
+   natts = tupdesc->natts;
 
    /*
-    * Connect to SPI manager
+    * Build sql statement to look up tuple of interest, ie, the one matching
+    * src_pkattvals.  We used to use "SELECT *" here, but it's simpler to
+    * generate a result tuple that matches the table's physical structure,
+    * with NULLs for any dropped columns.  Otherwise we have to deal with
+    * two different tupdescs and everything's very confusing.
     */
-   if ((ret = SPI_connect()) < 0)
-       /* internal error */
-       elog(ERROR, "SPI connect failure - returned %d", ret);
+   appendStringInfoString(&buf, "SELECT ");
 
-   /*
-    * Build sql statement to look up tuple of interest Use src_pkattvals as
-    * the criteria.
-    */
-   appendStringInfo(&buf, "SELECT * FROM %s WHERE ", relname);
+   for (i = 0; i < natts; i++)
+   {
+       if (i > 0)
+           appendStringInfoString(&buf, ", ");
+
+       if (tupdesc->attrs[i]->attisdropped)
+           appendStringInfoString(&buf, "NULL");
+       else
+           appendStringInfoString(&buf,
+                                  quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));
+   }
+
+   appendStringInfo(&buf, " FROM %s WHERE ", relname);
 
    for (i = 0; i < pknumatts; i++)
    {

diff --git a/contrib/dblink/expected/dblink.out b/contrib/dblink/expected/dblink.out
index 5bf8b5e98ab00b97e5d1889ca602c648dc08d2c5..f5503ce692c36440817718438f0eab44729072f4 100644 (file)
--- a/contrib/dblink/expected/dblink.out
+++ b/contrib/dblink/expected/dblink.out
@@ -804,3 +804,40 @@ SELECT dblink_disconnect('dtest1');
  OK
 (1 row)
 
+-- test dropped columns in dblink_build_sql_insert, dblink_build_sql_update
+CREATE TEMP TABLE test_dropped
+(
+   col1 INT NOT NULL DEFAULT 111,
+   id SERIAL PRIMARY KEY,
+   col2 INT NOT NULL DEFAULT 112,
+   col2b INT NOT NULL DEFAULT 113
+);
+NOTICE:  CREATE TABLE will create implicit sequence "test_dropped_id_seq" for serial column "test_dropped.id"
+NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "test_dropped_pkey" for table "test_dropped"
+INSERT INTO test_dropped VALUES(default);
+ALTER TABLE test_dropped
+   DROP COLUMN col1,
+   DROP COLUMN col2,
+   ADD COLUMN col3 VARCHAR(10) NOT NULL DEFAULT 'foo',
+   ADD COLUMN col4 INT NOT NULL DEFAULT 42;
+SELECT dblink_build_sql_insert('test_dropped', '2', 1,
+                               ARRAY['1'::TEXT], ARRAY['2'::TEXT]);
+                          dblink_build_sql_insert                          
+---------------------------------------------------------------------------
+ INSERT INTO test_dropped(id,col2b,col3,col4) VALUES('2','113','foo','42')
+(1 row)
+
+SELECT dblink_build_sql_update('test_dropped', '2', 1,
+                               ARRAY['1'::TEXT], ARRAY['2'::TEXT]);
+                                  dblink_build_sql_update                                  
+-------------------------------------------------------------------------------------------
+ UPDATE test_dropped SET id = '2', col2b = '113', col3 = 'foo', col4 = '42' WHERE id = '2'
+(1 row)
+
+SELECT dblink_build_sql_delete('test_dropped', '2', 1,
+                               ARRAY['2'::TEXT]);
+         dblink_build_sql_delete         
+-----------------------------------------
+ DELETE FROM test_dropped WHERE id = '2'
+(1 row)
+

diff --git a/contrib/dblink/sql/dblink.sql b/contrib/dblink/sql/dblink.sql
index c3984ae54c65838f7f7fcdb2aa619a4a33b1f2e0..77f8210415e7af2d0ff226fa1f7aefd8ffae3196 100644 (file)
--- a/contrib/dblink/sql/dblink.sql
+++ b/contrib/dblink/sql/dblink.sql
@@ -365,3 +365,29 @@ SELECT * from
 SELECT dblink_cancel_query('dtest1');
 SELECT dblink_error_message('dtest1');
 SELECT dblink_disconnect('dtest1');
+
+-- test dropped columns in dblink_build_sql_insert, dblink_build_sql_update
+CREATE TEMP TABLE test_dropped
+(
+   col1 INT NOT NULL DEFAULT 111,
+   id SERIAL PRIMARY KEY,
+   col2 INT NOT NULL DEFAULT 112,
+   col2b INT NOT NULL DEFAULT 113
+);
+
+INSERT INTO test_dropped VALUES(default);
+
+ALTER TABLE test_dropped
+   DROP COLUMN col1,
+   DROP COLUMN col2,
+   ADD COLUMN col3 VARCHAR(10) NOT NULL DEFAULT 'foo',
+   ADD COLUMN col4 INT NOT NULL DEFAULT 42;
+
+SELECT dblink_build_sql_insert('test_dropped', '2', 1,
+                               ARRAY['1'::TEXT], ARRAY['2'::TEXT]);
+
+SELECT dblink_build_sql_update('test_dropped', '2', 1,
+                               ARRAY['1'::TEXT], ARRAY['2'::TEXT]);
+
+SELECT dblink_build_sql_delete('test_dropped', '2', 1,
+                               ARRAY['2'::TEXT]);