Logical Key Assignments
There are two types of logical keys:
TABLE_KEY
This type is comparable only with another TABLE_KEY or a char that has a length of 8 bytes (char(8)).
OBJECT_KEY
This type is comparable only with another OBJECT_KEY or a char that has a length of 16 bytes (char(16)).
If a logical key column is declared as SYSTEM_MAINTAINED, the DBMS Server assigns the values to that column. System maintained logical key columns cannot be updated. If a logical key column is declared as NOT SYSTEM_MAINTAINED, values must be assigned to the column.
In embedded SQL programs, if values are assigned using host variables, the host variables must be char(8)-comparable for TABLE_KEY columns, and char(16)-comparable variables for OBJECT_KEY columns.
Values can be assigned to logical keys, not system maintained, using a hex constant or a string literal. For the format of a hex constant, see
String Literals (see page
String Literals).
Values assigned to TABLE_KEYs must be 8 bytes long. Values assigned to OBJECT_KEYs must be 16 bytes long. The following example inserts the value 1 into a TABLE_KEY column using a hex constant:
INSERT INTO test (tablekey) VALUES (TABLE_KEY(X'0000000000000001'));
The previous statement inserts 7 bytes containing 0, followed by 1 byte containing 1. The value is explicitly converted to a table key using the table_key conversion function.
The following example assigns the value 'abc' (padded to 8 characters for data type compatibility) to a logical key column:
INSERT INTO test (tablekey) VALUES (TABLE_KEY('abc'));