dblink_build_sql_delete — builds a DELETE statement using supplied values for primary key field values
dblink_build_sql_delete(text relname,
                        int2vector primary_key_attnums,
                        integer num_primary_key_atts,
                        text[] tgt_pk_att_vals_array) returns text    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.
   
relname       Name of a local relation, for example foo or
       myschema.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_attsThe number of primary key fields.
tgt_pk_att_vals_array       Values of the primary key fields to be used in the resulting
       DELETE command.  Each field is represented in text form.
      
Returns the requested SQL statement as text.
    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.
   
SELECT dblink_build_sql_delete('"MyFoo"', '1 2', 2, '{"1", "b"}');
           dblink_build_sql_delete
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 DELETE FROM "MyFoo" WHERE f1='1' AND f2='b'
(1 row)