iOS 数据库(2)

iOS 里面创建SQL语句

    NSString *sql_stmt;
    sql_stmt = @"create table\
    context_group\
    (context_group_id int(5) not null auto_increment,\
    context_group_title varchar(255)  not null,\
    context_group_father_id int(5),\
    \
    \
    \
    UNIQUE (context_group_id),\
    PRIMARY KEY (context_group_id),\
    FOREIGN KEY (context_group_father_id) REFERENCES context_group(context_group_id),\
    )";

** 出现这个错误 **
Error inserting batch: near "auto_increment": syntax error
===

在SQLite里面 INTEGER 才支持自增。
所以需要修改

context_group_id int(5) not null auto_increment

改成

context_group_id INTEGER auto_increment

---

iOS 里面 建表语句

    NSString *sql_stmt;
    sql_stmt = @"create table\
    email\
    (email_id INTEGER PRIMARY KEY auto_increment,\
    email VARCHAR(255)  not null,\
    UNIQUE(email_id))";
    return sql_stmt;

这样是会报错的

    NSString *sql_stmt;
    sql_stmt = @"create table\
    email\
    (email_id INTEGER auto_increment,\
    email_address VARCHAR(255)  not null,\
    UNIQUE(email_id),\
    PRIMARY KEY (email_id)\
    )";

这样才能正确执行

---

NSString *sql_stmt;
    sql_stmt = @"create table\
    tasks\
    (tasks_id INTEGER not null auto_increment,\
    tasks_title varchar(255) ,\
    UNIQUE(tasks_id),\
    PRIMARY KEY (tasks_id)\
    )";

这里会报错
Error inserting batch: near "auto_increment": syntax error
===
not null 和 auto_increment 不能一起用

---

SQLite 里面没有枚举类型
但是你可以这样用:

CREATE TABLE Price (
  PriceId INTEGER       PRIMARY KEY AUTOINCREMENT NOT NULL,
  Name    VARCHAR(100)  NOT NULL,
  Type    CHAR(1)       NOT NULL DEFAULT ('M') REFERENCES PriceType(Type)
);

CREATE TABLE PriceType (
  Type    CHAR(1)       PRIMARY KEY NOT NULL,
  Seq     INTEGER
);
INSERT INTO PriceType(Type, Seq) VALUES ('M',1);
INSERT INTO PriceType(Type, Seq) VALUES ('R',2);
INSERT INTO PriceType(Type, Seq) VALUES ('H',3);