contrib-dblink-build-sql-delete.md

## 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 an 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