Mysql 两个主键&；自动增量

我有一个MySQL表，有两个字段作为主键（ID和Account），ID具有自动增量。 这将导致以下MySQL表：

 ID    |  Account
------------------
 1     |     1
 2     |     1
 3     |     2
 4     |     3

但是，我预期会出现以下结果（重新启动每个帐户的

自动增量

）：

我的配置有什么问题？我怎样才能解决这个问题

---

谢谢

您所描述的功能只能通过

MyISAM

引擎实现。您需要像下面这样指定

CREATE TABLE

语句：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

创建您的表(
id INT无符号非空自动增量，
帐户id INT未签名非空，
主键（帐户id，id）
)发动机=MyISAM
您所描述的功能仅在使用
MyISAM
引擎时才可能实现。您需要像下面这样指定
CREATE TABLE
语句：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

创建您的表(
id INT无符号非空自动增量，
帐户id INT未签名非空，
主键（帐户id，id）
)发动机=MyISAM
如果使用innoDB引擎，可以使用如下触发器：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

注意！您的分隔符列在上面的sql语句中是#

此解决方案适用于您这样的表，如果您创建它时没有任何自动增量功能，如：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

现在，您可以按如下方式插入值：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

这将导致：

 ID    |  Account
------------------
 1     |     1
 2     |     1
 1     |     2
 1     |     3

如果使用innoDB引擎，可以使用如下触发器：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

注意！您的分隔符列在上面的sql语句中是#

此解决方案适用于您这样的表，如果您创建它时没有任何自动增量功能，如：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

现在，您可以按如下方式插入值：

CREATE TRIGGER `your_table_before_ins_trig` BEFORE INSERT ON `your_table`
FOR EACH ROW 
begin
declare next_id int unsigned default 1;

  -- get the next ID for your Account Number
  select max(ID) + 1 into next_id from your_table where Account = new.Account;

  -- if there is no Account number yet, set the ID to 1 by default
  IF next_id IS NULL THEN SET next_id = 1; END IF;

  set new.ID= next_id; 
end#

CREATE TABLE IF NOT EXISTS `your_table` (
  `ID` int(11) NOT NULL,
  `Account` int(11) NOT NULL,
  PRIMARY KEY (`ID`,`Account`)
);

INSERT INTO your_table (`Account`) VALUES (1);
INSERT INTO your_table (`Account`, `ID`) VALUES (1, 5);
INSERT INTO your_table (`Account`) VALUES (2);
INSERT INTO your_table (`Account`, `ID`) VALUES (3, 10205);

这将导致：

 ID    |  Account
------------------
 1     |     1
 2     |     1
 1     |     2
 1     |     3

什么是CREATETABLE语句和您使用的引擎？什么是CREATETABLE语句和您使用的引擎？