Specifies a validation check for a field. Oracle Rdb evaluates the
conditional expression at run time when the field is stored or
modified.
(B)0[mvalidity-clause =
qwq> [4mVALID[m [4mIF[m qqq> conditional-expr qwq>
mq> [4mNO[m [4mVALID[m [4mIF[m qqqqqqqqqqqqqqqqqqqqj
conditional-expr Specifies a valid conditional expression. This
conditional expression must refer only to the
field being defined. Ask for HELP on Cond_
expr for a complete description of Oracle Rdb
conditional expressions.
1 – Example
In the following example, the SHOW FIELD statement shows the
SEX field, which contains a VALID IF clause. The CHANGE FIELD
statement removes the VALID_IF clause from the SEX field:
RDO> DATA FILE DB$:PERSONNEL
RDO> SHOW FIELD SEX
SEX text size is 1
Description: M, F
Missing value: "?"
Valid: IF SEX = 'M' OR SEX = 'F' OR
SEX MISSING
RDO> CHANGE FIELD SEX NO VALID IF.
RDO> SHOW FIELD SEX
SEX text size is 1
Description: M, F
Missing value: "?"
RDO> ROLLBACK