Oracle:推迟开始/结束 block 中的约束？

Question

如何在开始/结束 block 内推迟约束？

这有效:

SQL> set constraint t_pk deferred;                                              
Constraint set.

但是相同的语句在开始/结束 block 中失败:

SQL> begin
2  set constraint t_pk deferred;
3  end;
4  /
set constraint t_pk deferred;
    *
ERROR at line 2:
ORA-06550: line 2, column 5:
PL/SQL: ORA-00922: missing or invalid option
ORA-06550: line 2, column 1:
PL/SQL: SQL Statement ignored

Answer 1

您需要使用立即执行:

begin
execute immediate 'set constraint t_pk deferred';
end;