PostgreSQL 9.3.6 Documentation
Prev | Up |  | Next

# dblink_build_sql_delete

## Name

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 `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_atts`

  The 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.

## 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)

Prev | Home | Next
dblink_build_sql_insert | Up | dblink_build_sql_update