dblink_build_sql_delete
dblink_build_sql_delete
dblink_build_sql_delete - builds a DELETE statement using supplied values for primary key field values
Synopsis
dblink_build_sql_delete(text relname,
int2vector primary_key_attnums,
integer num_primary_key_atts,
text[] tgt_pk_att_vals_array) returns text
Description
dblink_build_sql_delete
can be useful in doing selective
replication of a local table to a remote database. It builds a SQL
DELETE
command that will delete the row with the given
primary key values.
Arguments
-
relname -
Name of a local relation, for example
fooormyschema.mytab. Include double quotes if the name is mixed-case or contains special characters, for example"FooBar"; without quotes, the string will be folded to lower case. -
primary_key_attnums -
Attribute numbers (1-based) of the primary key fields, for example
1 2. -
num_primary_key_atts -
The number of primary key fields.
-
tgt_pk_att_vals_array -
Values of the primary key fields to be used in the resulting
DELETEcommand. Each field is represented in text form.
Return Value
Returns the requested SQL statement as text.
Notes
As of
PostgreSQL
9.0, the attribute numbers in
primary_key_attnums
are interpreted as logical
column numbers, corresponding to the column's position in
SELECT * FROM relname
. Previous versions interpreted the
numbers as physical column positions. There is a difference if any
column(s) to the left of the indicated column have been dropped during
the lifetime of the table.
Examples
SELECT dblink_build_sql_delete('"MyFoo"', '1 2', 2, '{"1", "b"}');
dblink_build_sql_delete
---------------------------------------------
DELETE FROM "MyFoo" WHERE f1='1' AND f2='b'
(1 row)