java - 在ANDROID SQLite中，是否可以在不将其设置为主键的情况下进行自动增量

Question

我在 Android Sqlite 中创建表时尝试使用 INTEGER AUTOINCRMENT。但它显示错误。但在提供 INTEGER PRIMARY KEY AUTOINCRMENT 时它工作得很好。

我的要求是，带有 AUTOINCRMENT 的列不应该是主键。

db.execSQL("CREATE TABLE " + Table_KOT_ITEMS_TEMP + "(" + col_Item_Name
                + " varchar(40) NOT NULL," + col_Ref_No
                + " int(11) NOT NULL DEFAULT '0'," + col_Table_No
                + " varchar(6) NOT NULL DEFAULT '0'," + col_Kot_No
                + " int(11) NOT NULL DEFAULT '0'," + col_Main_Item_Code
                + " varchar(10) NOT NULL," + col_Item_Type
                + " varchar(10) NOT NULL," + col_Item_Amount
                + " decimal(10,2) DEFAULT '0.00'," + col_Item_Qty
                + " decimal(9,3) NOT NULL DEFAULT '0.000'," + col_No_Of_Persons
                + " varchar(6) NOT NULL," + col_Dum_Unique
                + " varchar(25) NOT NULL," + col_CheckBox
                + " char(5) NOT NULL," + col_Item_Auto_ID
                + " INTEGER PRIMARY KEY AUTOINCREMENT)");

Answer 1

不直接。但您可以创建一个触发器来执行此操作。

 -- Create table
 CREATE TABLE testtbl (
     id INTEGER PRIMARY KEY,
     autoincr DEFAULT NULL,
     otherrow TEXT -- and maybe more
 );
 -- Create helper table
 CREATE TABLE sequence_helper (
     name TEXT PRIMARY KEY COLLATE NOCASE,
     seq INTEGER DEFAULT 1
 );
 -- Fill in the starting number
 INSERT INTO sequence_helper VALUES ('testtbl', 1);
 -- Create the trigger
 CREATE TRIGGER autoincr_testtbl AFTER INSERT ON testtbl FOR EACH ROW BEGIN
     UPDATE testtbl SET 
         autoincr = (SELECT seq FROM sequence_helper WHERE name = 'testtbl')
         WHERE rowid = new.rowid;
     UPDATE sequence_helper SET seq = seq+1 WHERE name = 'testtbl';
 END;

您可能可以通过检查 autoincr 列是否为 NULL 来改进这一点，但您应该了解基本概念。