Oracle:将序列设置为特定值

Question

我正在使用liquibase来管理我的架构.我有一堆插入语句.我已经硬编码了primary-id号码.完成所有插入操作后,我想将序列值更改为比表中主键的最大值多1.为此,我写了一个PL/SQL,如下所示.但是,当我执行select ArtifactTypes_id_seq.nextval from dual;它时仍然增加0.

SET SERVEROUTPUT ON SIZE 1000000
DECLARE
    sequence_id NUMBER;
BEGIN

    SELECT NVL(MAX(idArtifactType), 0) + 1 INTO sequence_id FROM ArtifactTypes;
    EXECUTE IMMEDIATE 'ALTER SEQUENCE saas.ArtifactTypes_id_seq INCREMENT BY ' || sequence_id;
    EXECUTE IMMEDIATE 'SELECT ArtifactTypes_id_seq.nextval FROM dual';
    EXECUTE IMMEDIATE 'ALTER SEQUENCE saas.ArtifactTypes_id_seq INCREMENT BY 1';
    DBMS_OUTPUT.put_line('Executed "ALTER SEQUENCE saas.ArtifactTypes_id_seq INCREMENT BY ' || sequence_id || '"');
END;
/

DBMS_OUTPUT提供以下输出 -
Executed "ALTER SEQUENCE saas.ArtifactTypes_id_seq INCREMENT BY 71"

我错过了什么？我做错了吗？注意:我尝试从SQLDeveloper执行这些SQL.

Answer 1

所以我发现了这个问题.以下应该是PL/SQL -

SET SERVEROUTPUT ON SIZE 1000000
DECLARE
    sequence_id NUMBER;
    temp_seq NUMBER;
BEGIN
    SELECT NVL(MAX(idArtifactType), 0) + 1 INTO sequence_id FROM ArtifactTypes;
    EXECUTE IMMEDIATE 'ALTER SEQUENCE saas.ArtifactTypes_id_seq INCREMENT BY ' || sequence_id;
    SELECT ArtifactTypes_id_seq.nextval into temp_seq FROM dual;
    EXECUTE IMMEDIATE 'ALTER SEQUENCE saas.ArtifactTypes_id_seq INCREMENT BY 1';
    DBMS_OUTPUT.put_line('Executed "ALTER SEQUENCE saas.ArtifactTypes_id_seq INCREMENT BY ' || sequence_id || '"');
END;
/

以下声明 -
EXECUTE IMMEDIATE 'SELECT ArtifactTypes_id_seq.nextval FROM dual';
已更改为
SELECT ArtifactTypes_id_seq.nextval into temp_seq FROM dual;

它工作了!!

Answer 2

您需要删除序列然后重新创建它,使用STARTS WITH子句分配初始值,例如:

CREATE SEQUENCE saas.ArtifactTypes_id_seq
  START WITH 72;

此外,从序列中选择NEXTVAL会自动将其递增1.