sqlite

SQlite数据库存储及增删改查例子

由 家住魔仙堡 提交于 2020-02-02 05:25:52
MainActivity: package com . example . databasetest ; import androidx . appcompat . app . AppCompatActivity ; import android . content . ContentValues ; import android . database . Cursor ; import android . database . sqlite . SQLiteDatabase ; import android . os . Bundle ; import android . util . Log ; import android . view . View ; import android . widget . Button ; public class MainActivity extends AppCompatActivity { private MyDatabaseHelper dbHelper ; @Override protected void onCreate ( Bundle savedInstanceState ) { super . onCreate ( savedInstanceState ) ; setContentView ( R . layout .

java.sql.SQLException: ResultSet closed

由 一世执手 提交于 2020-02-02 03:42:22
问题 I cant not do the further process because I get ResultSet closed while running this code. I am adding the value after 15 row of the sqlite database table and I want to find average value of 15 row and that should be store in ArrayList. Here is the code:- try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully3"); stmt = c.createStatement(); rs = stmt .executeQuery("SELECT TIME,BID

Does not load JDBC Library on ARM by execute Java Applikation

由 半腔热情 提交于 2020-02-01 17:37:05
问题 Ok We have a Java-application "app.jar" in a unix home directory with a external Sqlite Driver Library. - myapp/app.jar - myapp/lib/sqlite-jdbc-3.8.7.jar Device Udoo ARM Cortex V9 simliar to Raspberry Pi. java -version java version "1.8.0_06 Java(TM) SE Runtime Environment (build 1.8.0_06-b23) Java HotSpot(TM) Client VM (build 25.6-b23, mixed mode) Try to run this application failed. java -classpath lib/sqlite-jdbc-3.8.7.jar -jar myapp.jar It seems that the Application cannot find the Library

UniGUI的SQLite数据库(04)

由 为君一笑 提交于 2020-02-01 12:44:26
1]放FDConnection1和FDQuery1到界面上 2]在OnFormCreate事件里写 FDQuery1.Connection := FDConnection1; FDConnection1.LoginPrompt:=false; //取消登录提示框 FDConnection1.Open('DriverID=SQLite;Database=test1.Sqlite3');//test1.Sqlite数据库要与E:\UniGui_Learn\04OnLineIditom\Win32\Debug\Project1.exe位置一致 3]单条数据 FDQuery1.Open('select id,info from atb where id = 11111 ' ); unimemo1.Text:= FDQuery1.fieldbyname('info').asstring; 4]多条数据 FDQuery1.Open(‘select id,name,info from atb where 1=1’);//只读取第一个 unilistbox1.Items.Add( FDQuery1.fieldbyname('name').asstring); unimemo1.Text:= FDQuery1.fieldbyname('info').asstring; FDQuery1.next;

Using foreign keys in sqlite3 for Python

由 天大地大妈咪最大 提交于 2020-02-01 02:49:17
问题 I'm writing a program that creates a sqlite3 database through python. I have one table of Authors (AuthorID, Name) and a second table of books (BookID, Title, AuthorID) I've created these as shown below: Authors = sqlite3.connect('Authors.db') Authors.execute('''CREATE TABLE Authors (AuthorID INT PRIMARY KEY, Name TEXT);''') Authors.close() Books = sqlite3.connect('Books.db') Books.execute('''CREATE TABLE Books (BookID INT PRIMARY KEY, Title TEXT, AuthorID INT, FOREIGN KEY(AuthorID)

Read large file into sqlite table in objective-C on iPhone

由 纵然是瞬间 提交于 2020-01-31 20:36:23
问题 I have a 2 MB file, not too large, that I'd like to put into an sqlite database so that I can search it. There are about 30K entries that are in CSV format, with six fields per line. My understanding is that sqlite on the iPhone can handle a database of this size. I have taken a few approaches but they have all been slow > 30 s. I've tried: 1) Using C code to read the file and parse the fields into arrays. 2) Using the following Objective-C code to parse the file and put it into directly into

Read large file into sqlite table in objective-C on iPhone

由 主宰稳场 提交于 2020-01-31 20:34:31
问题 I have a 2 MB file, not too large, that I'd like to put into an sqlite database so that I can search it. There are about 30K entries that are in CSV format, with six fields per line. My understanding is that sqlite on the iPhone can handle a database of this size. I have taken a few approaches but they have all been slow > 30 s. I've tried: 1) Using C code to read the file and parse the fields into arrays. 2) Using the following Objective-C code to parse the file and put it into directly into

Read large file into sqlite table in objective-C on iPhone

由 こ雲淡風輕ζ 提交于 2020-01-31 20:33:19
问题 I have a 2 MB file, not too large, that I'd like to put into an sqlite database so that I can search it. There are about 30K entries that are in CSV format, with six fields per line. My understanding is that sqlite on the iPhone can handle a database of this size. I have taken a few approaches but they have all been slow > 30 s. I've tried: 1) Using C code to read the file and parse the fields into arrays. 2) Using the following Objective-C code to parse the file and put it into directly into

SQLite数据库---sql语句的基础使用

由 拥有回忆 提交于 2020-01-31 14:26:19
1.什么是SQLite数据库 SQLite数据库是一种轻量级的、嵌入式的、ACID数据库； **轻量级：**没有MySql、Oracle、SQL Server那么大，那么重量级 **嵌入式：**在手机内部的，可以导出 **ACID：**原子性（事务的处理要么一起执行，要么不执行）、一致性（事务使数据库的数据从一个状态到另一个状态）、隔离性（事务并发带来的问题，像脏读、不可重复读、幻读，通过隔离级别来避免，至少要避免脏读）、持久性（当事务提交之后，对数据库中的数据改变是永久性的） 2.SQLite数据库的优缺点 优点： （1）上边说到过的轻量级数据库就是优点之一，还有就是无需配置，高效； （2）动态数据类型：比如说在使用MySql数据库时，在创建表时，要确定每个字段的类型，int、varchar、date等等，在插入该表时，插入的数据要符合创建表时字段的类型；但是SQLite数据库不一样，如果第一次插入int类型数据，第二次插入String类型数据也是可以的。 缺点： （1）因为是单一文件，所以并发性能要差一些；因此在使用SQLite时，所有的表、索引等都是在同一个文件中，在并发查询多张表时效率就很低； （2）网络文件的存储。 3.SQLite数据库的用途 （1）APP运行时数据的保存 （2）离线功能：在没有网络的情况下，可以查看历史记录，将历史数据保存在SQLite数据库； （3

mysql到sqlite数据传输

由 我们两清 提交于 2020-01-31 09:21:27
在实际的工作中需要将mysql数据库表中的数据同步到sqlite对应的表中，主要有两种方法。第一种是使用Navicat里的数据传输，第二种是使用程序来实现。 第一种、程序实现 1、添加sqlite驱动 本项目是通过maven管理，在pom.xml中添加sqlite的驱动包依赖。 < dependency > < groupId > org . xerial < / groupId > < artifactId > sqlite - jdbc < / artifactId > < version > 3.19 .3 < / version > < / dependency > 2、复制模板文件 运用FileUtils来复制模板pad.db文件 String padPath = 'D:\\pad.db' ; FileUtils . copyDirectory ( new File ( padPath ) , new File ( "c:\\pad.db" ) ; 3、建立sqlite连接 从mysql数据库中查询出拼接的字段，传输到sqlite数据库对应的表中。 //建立连接 Class . forName ( "org.sqlite.JDBC" ) ; Connection c = DriverManager . getConnection ( "jdbc:sqlite
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