PostgreSQL 9.4表中的唯一ID

Question

我想在PostgreSQL 9.4表中插入唯一的ID记录。

INSERT INTO ACCOUNT_HISTORY(ID, ACCOUNT_ID, USERNAME, COMMENT, CREATED) VALUES (?, (select ID from ACCOUNT where USER_NAME = ?), ?, ?, CURRENT_DATE) 

表

CREATE TABLE ACCOUNT_HISTORY(
ID INTEGER NOT NULL, 
ACCOUNT_ID INTEGER, 
USERNAME TEXT, 
COMMENT TEXT, 
CREATED DATE 
) 
; 

CREATE INDEX IX_RELATIONSHIP8 ON ACCOUNT_HISTORY (ACCOUNT_ID) 
; 

怎样才能为每一个插入查询唯一的ID？

Answer 1

使用serial：

CREATE TABLE ACCOUNT_HISTORY (
    ID SERIAL, 
    ACCOUNT_ID INTEGER, 
    USERNAME TEXT, 
    COMMENT TEXT, 
    CREATED DATE 
); 

然后，不包括其在insert声明：

INSERT INTO ACCOUNT_HISTORY(ACCOUNT_ID, USERNAME, COMMENT, CREATED) 
    SELECT ID, ?, ?, ?, CURRENT_DATE 
    FROM ACCOUNT 
    WHERE USER_NAME = ?; 

编辑：

如果您在表中有数据（所以你不”不想丢掉它）：

create temporary table temp_account_history as 
    select * 
    from account_history; 

drop account_history; 

CREATE TABLE ACCOUNT_HISTORY (
    ID SERIAL, 
    ACCOUNT_ID INTEGER, 
    USERNAME TEXT, 
    COMMENT TEXT, 
    CREATED NOT NULL DEFAULT CURRENT_DATE 
); 

INSERT INTO ACCOUNT_HISTORY(ACCOUNT_ID, USERNAME, COMMENT, CREATED) 
    SELECT ACCOUNT_ID, USERNAME, COMMENT, CREATED 
    FROM TEMP_ACCOUNT_HISTORY; 

请注意，这也给CREATED一个默认值，所以你不必在随后的插入中包含它。