База данных / IS_to_STUD / Soft / 2.1.0.17798-Final / Firebird-2.1.0.17798-0_Win32 / doc / sql.extensions / README.update_or_insert

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UPDATE OR INSERT statement
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Function:
Allow to update or insert a record based on the existence (checked with IS NOT DISTINCT) or not of it.

Author:
Adriano dos Santos Fernandes <adrianosf@uol.com.br>

Syntax rules:
UPDATE OR INSERT INTO <table or view> [(<column_list>)]
VALUES (<value_list>)
[MATCHING <column_list>]
[RETURNING <column_list> [INTO <variable_list>]]

Scope:
DSQL, PSQL

Examples:
1. UPDATE OR INSERT INTO T1 (F1, F2) VALUES (:F1, :F2);
2. UPDATE OR INSERT INTO EMPLOYEE (ID, NAME) VALUES (:ID, :NAME) RETURNING ID;
3. UPDATE OR INSERT INTO T1 (F1, F2) VALUES (:F1, :F2) MATCHING (F1);
4. UPDATE OR INSERT INTO EMPLOYEE (ID, NAME) VALUES (:ID, :NAME) RETURNING OLD.NAME;

Notes:
1. When MATCHING is omitted, the existence of a primary key is required.
2. INSERT and UPDATE permissions are needed on <table or view>.
3. If the RETURNING clause is present, then the statement is described as
isc_info_sql_stmt_exec_procedure by the API. Otherwise it is described
as isc_info_sql_stmt_insert.

Limitation:
1. A singleton error will be raised if the RETURNING clause is present and more than
one record match the condition.