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1.sqlite數(shù)據(jù)庫數(shù)據(jù)類型

Integer?varchar(10)?float?double?char(10)?text

2.sql回顧

2.1創(chuàng)建表的語句
create?table?表名(字段名稱?數(shù)據(jù)類型?約束，字段名稱?數(shù)據(jù)類型?約束......)
create?table?person(_id?Integer?primary?key,name?varchar(10),age?Integer?not?null)

2.2?刪除表的語句
drop?table?表名
drop?table?person

2.3?插入數(shù)據(jù)
insert?into?表名[字段，字段]?values(值1，值2......)
insert?into?person(_id,age)?values(1,20)
insert?into?person?values(2,"zs",30)

2.4?修改數(shù)據(jù)
update?表名?set?字段?=?新值?where?修改的條件
update?person?set?name="ls",age=20?where?_id=1

2.5?刪除數(shù)據(jù)
delete?from?表名?where?刪除的條件
delete?from?person?where?_id=2

2.6?查詢語句
select?字段名?from?表名?where?查詢條件?group?by?分組的字段?having?篩選條件?order?by?排序字段
select?*?from?person;

select?_id,name?from?person
select?*?from?person?where?_id=1
select?*?from?person?where?_id<>1
select?*?from?person?where?_id=1?and?age>18
select?*?from?person?where?name?like?"%小%"
select?*?from?person?where?name?like?"_小%"
select?*?from?person?where?name?is?null
select?*?from?person?where?age?between?10?and?20
select?*?from?person?where?age>18?order?by_id

Sqlite數(shù)據(jù)庫基本數(shù)據(jù)類型

sqlite數(shù)據(jù)庫創(chuàng)建

sqlite 查詢語句

select * from person where _id<>1? ? ? ? ==>? ?_id 不等于1

select * from person where name like "%小%"? ? ==>只要中間含有小，前后可以有任意多的字符

select*? from person where name like "_小%"? ==>一個字符后面是小，后面可以有任意多的。

select * from person where name is null? ? ==> 查詢名字為空的

select * from person where age is 10 between 20

select * from person where age >18 order by _id? ==> >18且根據(jù)—id指定排序

sqlite數(shù)據(jù)庫類型

getreadableDatabase與getWritableDatabase的區(qū)別

getReadableDatabase()? getWritableDatabase()

sql 基本回顧

SQLite 數(shù)據(jù)庫增刪改查的方法：

1:調(diào)用execSQL（sql）語句，需要記住正確的sql語句

2:使用api封裝好的增刪改查的操作，填寫方法中對應的條件

1. sqlite數(shù)據(jù)庫類型
   

   Integer????? varchar(10)????? float????? double????? char(10)??????? text

2. sql語句回顧

   2.1.創(chuàng)建表的語句

   create table 表名（字段名稱? 數(shù)據(jù)類型?? 約束，字段名稱?? 數(shù)據(jù)類型?? 約束......）

????????????eg:? create table person(_id Integer primary key,name varchar(10),age Integer not null)

????????????2.2 刪除表的語句

????????????drop table 表名

????????????eg:drop table person

?????????????2.3 插入數(shù)據(jù)

????????????insert into 表名[字段1,字段2......] values(值1,值2......)

????????????eg: insert into person(_id,age) values(1,20)

????????????eg: insert into person values(2,"zj",30)??? //按照表字段的順序插入所有字段的值（不能缺少）

????????????2.4 修改數(shù)據(jù)

????????????update 表名 set 字段 = 新值 where 修改的條件

????????????eg: update person set nam="wzj" ，age=20 where _id=1?? //不加where條件語句表明表中的所有name都修改成“wzj”,age都修改成20

??? ????????2.5 刪除數(shù)據(jù)

????????????delete from 表名 where 刪除的條件

????????????delete from person where _id=2??? //不加where條件語句表明刪除person表中所有字段

????????????2.6 查詢語句

????????????selete 字段名 from 表名 where 查詢條件 group by 分組的字段 having 篩選條件 order by 排序字段

????????????selete * from person;

?????????????selete _id ,name from person;

????????????selete * from person where _id=1

????????????selete * from person where _id<>1? //_id不等于1

????????????selete * from person where _id=1 and age>18

????????????selete * from person where name like "%z%"

????????????selete * from person where name like "_z%"

????????????selete * from person where name is null

????????????selete * from person where age between 10 and 20

????????????selete * from person where age>18 order by _id

/*
??一、創(chuàng)建一個類MySQLiteOpenHelper繼承SQLiteOpenHelper，實現(xiàn)onCreate和onUpgrade
??方法。
??二、創(chuàng)建常量類Constant，將庫名表名之類的寫進去。
??public?class?Constant?{
????public?static?final?String?DASEBASE_NAME?=?"user.db";
????public?static?final?int?VERSION?=?1;
????public?static?final?String?TABLE_NAME?=?"students";
????public?static?final?String?_ID?=?"_id";
????public?static?final?String?STUDENT_NAME?=?"name";
????public?static?final?String?STUDENT_SEX?=?"sex";
????public?static?final?String?STUDENT_AGE?=?"age";
}
??三、創(chuàng)建數(shù)據(jù)庫管理類，用單例模式獲得幫助類實例。
??public?class?DbManger?{
????private?static?MySQLiteOpenHelper?helper;

????public?static?MySQLiteOpenHelper?getIntance(Context?context)?{
????????if?(helper?==?null)?{
????????????helper?=?new?MySQLiteOpenHelper(context);
????????}
????????return?helper;
????}
}
??四、創(chuàng)建數(shù)據(jù)庫
??private?MySQLiteOpenHelper?helper;
??helper?=?DbManger.getIntance(this);
??SQLiteDatabase?db?=?helper.getWritableDatabase();
*/

public?void?onClick(View?view){
???switch(view.getId()){
??????case?R.id.***:
??????break;
??????case?R.id.***:
??????break;
??????default:
??????break;
???}
}

Android 內(nèi)置

sqlite常用命令：

創(chuàng)建表：create table 表名（字段名 數(shù)據(jù)類型 約束 ，...）

刪除表：drop table 表名

插入數(shù)據(jù)：insert into 表名 [字段,字段]? values（值1，值2...）

????????????????例：insert into person （_id,age）values(1,20)

????????????????或：insert into person (2,"zc",28)

修改數(shù)據(jù)；update 表名 set 字段=新值 where 修改條件

????????????????例：update person set name ="zc",age = 20 where _id = 1

刪除數(shù)據(jù)：delete from 表名 where 刪除條件?

????????????? ?例： delete from person where _id=2

查詢數(shù)據(jù)：select 字段名 from 表名 where 查詢條件 group by 分組字段? having 篩選條件 order by 排序字段?

什么是Sqlite?

小型的，零配置，可嵌入的，開源的，支持事務操作的，無數(shù)據(jù)類型的，程序驅(qū)動的關(guān)系型數(shù)據(jù)庫

Sqlite的介紹：

跨平臺的磁盤文件

代碼量少

api簡單易用

1.sqlite數(shù)據(jù)庫數(shù)據(jù)類型

Integer varchar(10) float char(10) text

2.sql回顧

2.1 創(chuàng)建表語句
?? ?create table 表名(字段名稱 數(shù)據(jù)類型 約束,字段名稱 數(shù)據(jù)類型 約束.....)
?? ?create table person(_id Integer primary key, name varchar(10), age Integer not null)
2.2 刪除表的語句
?? ?drop table 表名
?? ?drop table person
2.3 插入數(shù)據(jù)
?? ?insert into 表名[字段,字段] values(值1,值2.....)
?? ?insert into person values(2,"zs",30)
2.4 修改數(shù)據(jù)
?? ?update 表名 set 字段=新值 where 修改的條件
?? ?update person set name="ls",age=20 where _id=1
2.5 刪除數(shù)據(jù)
?? ?delete from 表名 where 刪除的條件
?? ?delete from person where _id=2
2.6 查詢語句
?? ?select 字段名 from 表名 where 查詢條件 group by 分組的字段 having 篩選條件 order by 排序字段
?? ?select * from person;
???