INSERT statement with a full select

Derby Reference Manual

129

Derby supports the IDENTITY_VAL_LOCAL function.

Syntax:

IDENTITY_VAL_LOCAL ( )

The IDENTITY_VAL_LOCAL function is a non-deterministic function that returns the most
recently assigned value of an identity column for a connection, where the assignment
occurred as a result of a single row INSERT statement using a VALUES clause.

The IDENTITY_VAL_LOCAL function has no input parameters. The result is a DECIMAL
(31,0), regardless of the actual data type of the corresponding identity column.

The value returned by the IDENTITY_VAL_LOCAL function, for a connection, is the
value assigned to the identity column of the table identified in the most recent single
row INSERT statement. The INSERT statement must contain a VALUES clause on a
table containing an identity column. The function returns a null value when a single row
INSERT statement with a VALUES clause has not been issued for a table containing an
identity column.

The result of the function is not affected by the following:

· A single row INSERT statement with a VALUES clause for a table without an

identity column

· A multiple row INSERT statement with a VALUES clause
· An INSERT statement with a fullselect

If a table with an identity column has an INSERT trigger defined that inserts into another
table with another identity column, then the IDENTITY_VAL_LOCAL() function will return
the generated value for the statement table, and not for the table modified by the trigger.

Examples

ij> create table t1(c1 int generated always as identity, c2 int);
0 rows inserted/updated/deleted
ij> insert into t1(c2) values (8);
1 row inserted/updated/deleted
ij> values IDENTITY_VAL_LOCAL();
1
-------------------------------
1
1 row selected
ij> select IDENTITY_VAL_LOCAL()+1, IDENTITY_VAL_LOCAL()-1 from t1;
1 |2
-------------------------------------------------------------------
2 |0
1 row selected
ij> insert into t1(c2) values (IDENTITY_VAL_LOCAL());
1 row inserted/updated/deleted
ij> select * from t1;
C1 |C2
-------------------------------
1 |8
2 |1
2 rows selected
ij> values IDENTITY_VAL_LOCAL();
1
-------------------------------
2
1 row selected
ij> insert into t1(c2) values (8), (9);
2 rows inserted/updated/deleted
ij> -- multi-values insert, return value of the function should not
change
values IDENTITY_VAL_LOCAL();
1
-------------------------------